Tetrapod Zoology

Regular readers will know that I’m not exactly a fan of the idea – discussed here and there in the technical (Russell & Séguin 1982, Russell 1987), popular (Hecht 2007, Socha 2008, Naish 2008) and speculative literature (McLoughlin 1984, Magee 1993) – that non-avian theropod dinosaurs might have evolved into humanoids had they not bought the farm 65 million years ago [image below by Matt Collins].

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The hypothetical (emphasis: hypothetical) evolution of big brains, intelligence and so on among imaginary post-Cretaceous deinonychosaurs is not (in my opinion) all that unreasonable, and I base this assertion on what birds have been doing over the past 65 million years. Look at parrots and corvids. Parrots overlap with primates in brain : body size ratio, intelligence and abilities, and evidence suggests that they (and corvids) have sophisticated emotions that aren’t much different from ours (or from those of other primates; humans are not magic animals different from all the others, but part of a spectrum). You probably heard the recent reports about funeral rites in magpies. This was in the news thanks to the publication of Bekoff’s paper (Bekoff 2009), but stuff like this has been widely reported anecdotally and there’s every reason to take it seriously [Alex the grey parrot (1976-2007) shown below, from wikipedia].

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However… as for the idea that those bird-like dinosaurs might have evolved into bolt upright, tailless humanoids… well, it’s a thoroughly stupid idea and I’m sure you don’t need me to go through the arguments again (see the links below if you’re unfamiliar with them). To put it as succinctly as possible, our body shape is the product of our very specific evolutionary history, and can we be absolutely sure that it’s ‘the best’ body shape for the evolution of big brains or intelligence? Yes or no (I think no), there doesn’t seem to be any indication (either from fossils, or from actual post-Cretaceous dinosaurs, by which I mean birds) that dinosaurs would go this way, big brain or no.

So it’s slightly surprising to see well known evolutionary biologist and author Richard Dawkins take up the mantle of ‘humanoid dinosaur’ supporter in an article Michael Shermer has written for Scientific American. Things started with Shermer’s argument that aliens – if real – will not resemble bipedal primates (he put this forward in a brief youtube video). Dawkins mostly agreed, but also responded with the argument that perhaps the odds aren’t so vanishingly small after all, citing Simon Conway Morris’s opinions and the dinosauroids of the speculative literature in his defence!

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An interpretation of Conway Morris’s argument is that (1) the human body shape really is the best shape for intelligence and sentience, and (2) convergence is so rampant throughout life on Earth that it very likely extends to life on other planets too. Point (2) may be reasonable, but point (1) seems less so. Dawkins is quoted as saying that Conway Morris’s argument “is not to be dismissed”. No, sorry, that’s not how it works. It doesn’t matter if Conway Morris is the world’s bestest ever expert on… whatever he’s the world’s bestest ever expert on: he can still be wrong, or hold questionable opinions, just like the rest of us. If I may use a Carl Sagan quote, there are no authorities, only experts, and there are many who think that Conway Morris’s argument about the inevitability of humans or humanoids is only an opinion, and a dodgy, biased one at that. Our body shape clearly works well for an intelligent, tool-using, sentient animal, but where is the convincing evidence that it is the only possible body shape for such a creature, or the most likely one to evolve in distantly related, or unrelated, organisms? I’m afraid I can’t help but see promotion of ‘magic human syndrome’ in Conway Morris’s arguments (this being the widespread belief that humans are the most wonderful, most perfect creatures in all of existence).

To make it clear, however, Dawkins doesn’t necessarily support or endorse the possibility that non-avian dinosaurs might have become humanoid. Rather, he is merely pointing to the fact that at least a few scientists have speculated on this possibility. But I thought he would have known better, given that these speculations do not really seem justifiable.

For previous articles on ‘smart dinosaurs’, please see…

More on Libya soon, plus more toads and so on. Thanks to Nathan Myers for the heads-up. On the subject of dinosaurs, congrats to Adam Yates on Aardonyx, and to Herman Pontzer and colleagues for their PLoS ONE paper on dinosaur physiology. Empirical support for dinosaur endothermy: what a surprise :)

Refs – –

Bekoff, M. 2009. Animal emotions, wild justice and why they matter: grieving magpies, a pissy baboon, and empathic elephants. Emotion, Space and Society doi: 10.1016/j.emospa.2009.08.001

Hecht, J. 2007. Smartasaurus. Cosmos 15, 40-41.

Magee, M. 1993. Who Lies Sleeping: the Dinosaur Heritage and the Extinction of Man. AskWhy! Publications, Frome.

McLoughlin, J. 1984. Evolutionary bioparanoia. Animal Kingdom April/May 1984, 24-30.

Naish, D. 2008. Intelligent dinosaurs. Fortean Times 239, 52-53.

Russell, D. A. 1987. Models and paintings of North American dinosaurs. In Czerkas, S. J. & Olson, E. C. (eds) Dinosaurs Past and Present, Volume I. Natural History Museum of Los Angeles County/University of Washington Press (Seattle and Washington), pp. 114-131.

– . & Séguin, R. 1982. Reconstruction of the small Cretaceous theropod Stenonychosaurus inequalis and a hypothetical dinosauroid. Syllogeus 37, 1-43.

Socha, V. 2008. Dinosauři: hlupáci, nebo géniové? Svĕt 3/2008, 14-16.

Comments

  1. #1 Dartian
    November 11, 2009

    convergence is so rampant throughout life on Earth that it very likely extends to life on other planets too

    Indeed it does. Haven’t you noticed that in Hollywood movies, not only are space aliens bipedal but they have also usually evolved a language that sounds exactly like English? (If the aliens are friendly, they speak with what sounds like an American accent and if they’re evil, they speak with what sounds like a British accent.) Proof positive of the all-pervasive power of convergence.

    Seriously though, I must confess that I haven’t read any of his books but if Simon Conway Morris* really has said that

    the human body shape really is the best shape for intelligence and sentience

    I can only shake my head in disbelief. That’s data extrapolation on a huge scale, to put it mildly.

    * Pre-emptive reminder: Disagree with his ideas all you want, but please get the man’s name right. His surname is ‘Conway Morris’, not ‘Morris’. (I’ve seen quite a few people get this wrong.)

  2. #2 David Marjanović, OM
    November 11, 2009

    Conway Morris overlooks that convergence is indeed rampant when you subject the same morphology to the same selective pressures, but not at all when you try that with different starting points. For instance, sabre-toothed synapsids evolved again and again, but sabre-toothed sauropsids… diapsids with any kind of distinct caniniform teeth in the maxilla are almost limited to sphenodontines.

    And besides, he’s quite clearly motivated by religion. I’m rather surprised Dawkins didn’t notice. :-)

  3. #3 David Marjanović
    November 11, 2009

    (Oops, wrong choice on the name auto-fill-in.)

    I’ve seen quite a few people get this wrong.

    Why actually doesn’t he use a hyphen?

  4. #4 Thomas R. Holtz, Jr.
    November 11, 2009

    I’ve said before, I guess I’ll have to say it again:

    Avoid the ‘Roid!

    (For those of you who weren’t around in the 1980s, a reference to a series of old Domino’s Pizza commericals, such as http://www.youtube.com/watch?v=bri0SA7FTf4).

  5. #5 Daniella Perea
    November 11, 2009

    I very much agree on the religion thing. It seems to me that most people who endorse “magic human syndrome” are religious and need humans to have a special place in the universe. Not all however. Other people endorse it because they are unaware of data showing that humans are simply not special creatures: they think that our anatomy, emotions, brain size and so on are unique.

  6. #6 Sesu
    November 11, 2009

    One small point.

    “Parrots overlap with primates in brain : body size ratio, intelligence and abilities”

    Brain/body size ratios are hardly the be-all and end all of predicting intelligence. Salticids have very small brains, even in respect to their body size, but have exceptionally complex behavior. I remember a jumping spider researcher telling me that they can do everything a lion can, except roar. Pretty impressive for a brain that fits on the head of a pin!

  7. #7 Darren Naish
    November 11, 2009

    Yes: the largest brains on the planet (in proportion to body size) occur in elephant-nose fishes (and apparently in some hymenopterans, though I can’t find out which ones). The question I was asking is: would post-Cretaceous deinonychosaurs evolve primate-like intelligence?

  8. #8 Darren Naish
    November 11, 2009

    Sorry, the ‘yes’ in comment 7 refers to the “Brain/body size ratios are hardly the be-all and end all of predicting intelligence” in comment 6. As in: yes, I know, thanks :)

  9. #9 Dartian
    November 11, 2009

    David:

    he’s quite clearly motivated by religion. I’m rather surprised Dawkins didn’t notice

    I’m almost sure that Dawkins has noticed (and even commented on it in at least one of his books – The Ancestor’s Tale, perhaps?), but maybe this is at least partly a ‘the enemy of my enemy is my friend’-thing? Conway Morris has been a vocal and pretty aggressive critic of Stephen Jay Gould’s writings, so maybe Dawkins is therefore willing to cut him more slack regarding his religious beliefs?

    Why actually doesn’t he use a hyphen?

    Because he just doesn’t, I’d suppose. Conway Morris is, of course, not the only notable person of UK origin with a multi-part, non-hyphenated surname. For example, I remember being rather annoyed when I recently read a history book where the (American) author kept referring to a British Prime Minister by the surname ‘George’. The author meant, of course, David Lloyd George (who, in spite of his surname, ‘Lloyd George’, was Welsh*).

    * I’ve made the observation that 95% of all Welsh people seem to have the surname ‘Jones’, as this virtually comprehensive list of famous Welsh people clearly shows: Tom Jones, Catherine Zeta-Jones, Vinnie Jones, Griff Rhys Jones, Terry Jones (from Monty Python), Steve Jones (the biologist)…

  10. #10 The Ridger
    November 11, 2009

    The predominance of “Jones” as a surname in Wales comes from the popularity of John as a name in the generation that preceded the UK’s passing a law that forced the Welsh to adopt surnames instead of patronymics.

    Conan Doyle is another without a hyphen. So is Baker Finch (Ian, the golfer).

  11. #11 NoAstronomer
    November 11, 2009

    “The question I was asking is: would post-Cretaceous deinonychosaurs evolve primate-like intelligence?”

    The question I want to ask is : Could pre-Cretaceous deinonychosaurs have evolved primate-like intelligence? The record is sparse enough that it could have happend and we simply wouldn’t see it.

    @Dartian

    There’s a (very) old joke about that. Google “Jones the spy”.

  12. #12 Dave H
    November 11, 2009

    “The question I want to ask is : Could pre-Cretaceous deinonychosaurs have evolved primate-like intelligence? The record is sparse enough that it could have happend and we simply wouldn’t see it.”

    I think that’s a really good point. If worked flints, for example, occurred in Cretaceous deposits, would anyone recognize them for what they are? I imagine they would stand out as tools if they were as sophisticated as Acheulean hand-axes, but perhaps not if they were of the simpler, “Oldowan” type. I imagine that the average Cretaceous geologist or dinosaur paleontologist has little or no expertise on stone tools and might just overlook them. But then again, hypothetical intelligent deinonychosaurs with sickle-clawed feet and a jaw-full of sharp teeth might have had no need of flint tools in the way our hominid ancestors did, in which case what other evidence of advanced intelligence could we expect to survive for 65+ million years?

  13. #13 Kevin Schreck
    November 11, 2009

    By the way, when will we see more of Nemo Ramjet’s wonderful Avisapiens and their artwork? His old website is currently down, and most of the remaining artwork is only on his DeviantArt page.

  14. #14 amphiox
    November 11, 2009

    The thing is, most the supposed advantages of the “humanoid” body shape for an intelligent, social, tool-using species, such as the foreward facing eyes for binocular vision, the free hands for manipulating the world, etc, deinonychosaurs already had! (And they get spared the low back pain and the perils of live-birthing big-headed offspring through a pelvis narrowed by the demands of bipedalism, too)

    So even given a hypothetical scenario wherein a lineage of deinoychosaurs starts to evolve towards primate-like intelligence, I don’t see any likely set of selective pressures that might drive them towards convergently evolving towards an upright humanoid body shape.

  15. #15 Sven DiMilo
    November 11, 2009

    Conan Doyle is another without a hyphen. So is Baker Finch

    Throatwarbler Mangrove.

  16. #16 alanborky
    November 11, 2009

    Surely the reason for the tenacity of the dinohumanoids is because the image used to represent them is invariably suggestive of the so-called greys – so much so, one wonders whether someone’s trying to hint or imply something, especially since some alleged UFO contactees’ve supposedly encountered lizard men?

    I agree with you, though.

    I remember once watching this guy without arms playing the guitar with his feet for the Pope and I instantly knew hands weren’t such a big deal as they’re always made out to be – and I’m an artist and a musician! – and then when I watched the skill with which crows could manipulate things with both their beaks and feet I remembered Gurdjieff’s allegorical account of the race of super intelligent Space Ravens and wondered if he knew more than he was letting on…

    And’ve you ever seen the videos of the skillful and intelligent ways octopuses (octopii) can use their tentacles?

    It’s actually the obsession with the supposed perfection of the human form that’s allowed so many scientists over the years to ignore centuries of anecdotal data concerning remarkable animal behaviour that is only now beginning to be taken heed of.

  17. #17 amphiox
    November 11, 2009

    “Could pre-Cretaceous deinonychosaurs have evolved primate-like intelligence?”

    One argument against, although somewhat weakened by the sparcity of the fossil record, is that even the most intelligent of known pre-Cretaceous deinonychosaurs would have ranked in the lower end of the spectrum among modern birds, at least as estimated by comparing brain/body ratios using endocasts. Since the estimated intelligence of the pre-Cretaceous birds was also on par with that of their dinosaur relatives (and lower than that of their modern descendants), it would suggest that the entire clade had not yet had the opportunity or perhaps the time necessary to evolve the higher intelligence levels achieved by the brightest of the modern birds.

  18. #18 Dave H
    November 11, 2009

    It’s touching to see how the hypothetical dino-hominids in the painting above apparently share the same Flintstones-esque fashion sense that “cavemen” are always given in popular books.

    I look forward to seeing “65 Million Years BC” with a Raquel Welch-alike dinosauroid in a fur bikini, although sadly being a reptile she wouldn’t have the equipment necessary to fill the top half!

  19. #19 amphiox
    November 11, 2009

    Pareidolia, I think, will somewhat increase the odds that we will find another intelligent lifeform to be “humanoid”, inasmuch that we will have a tendency to think of it as humanoid even if it really isn’t.

    Consider that deinonychosaur. It’s got a pair of forward facing eyes, a nose, a mouth with teeth, a tongue. It may have a tuft of fuzzy feathers over the top of its head. It’s got two grasping arms, and two legs. So what if it has a tail and leans over somewhat? You can already consider it to be “humanoid”!

    And think of an octopus. How many times have we seen them portrayed with their mantle projecting upwards like a domed head, their eyes staring forward and the tentacles dangling down like some kind of weird facial hair. If we found a alien species that looks even a bit like that, I suspect we’d call it “humanoid” too.

  20. #20 Chris Greenhill
    November 11, 2009

    On Earth at least, I think at least a near humanoid body plan for an intelligent species occurring may not be completely unlikely, but far from a certainty. As was said, this shape works, and if it works well once it could probably work again.

    In considering the possible body shapes and forms that alien intelligent life may take, it seems that there are so many unknowns and variables. Imagine all the possible strange selective pressures that could drive evolution down wildly different paths on an alien world. Even given the constraints that carbon based life has (needing relatively stable conditions for liquid water for billions of years, certain proportions of other elements, ect.), it seems to me that there’s a myriad of possible selective pressures. Different gravities, atmospheric compositions, even the light from the star the world orbits (would photosynthesizing organisms use carotene rather than chlorophyll if the primary star was a red dwarf). On an ocean only world with no land masses sticking up, you certainly wouldn’t expect a terrestrial humanoid body plan to appear (assuming complex life could even evolve at all on such a world).

  21. #21 Don Cox
    November 11, 2009

    One reason we are bipedal is that the first land vertebrates had only four “legs”. If they had had six, we could have a pair for walking, a pair for wings, and a pair for handling tools; and there would be centaurs and winged horses or (small) dragons.

    But I think the octopus layout is more practical in many ways, except that (IIRC) they have a brain which is a ring around the gut – not good.

  22. #22 David Ullery
    November 11, 2009

    I cannot believe that there are actually people spending more than an hour or two thinking about this.

    I think your own words say it all:

    “To make it clear, however, Dawkins doesn’t necessarily support or endorse the possibility that non-avian dinosaurs might have become humanoid. Rather, he is merely pointing to the fact that at least a few scientists have speculated on this possibility.”

    Remove the word “necessarily”. You are using a popular science figure to get people to read this.

    Crows are smart, have big brains, solve problems. Birds evolved from dinosaurs. They have two legs and walk on them. An upright position, like a human, takes far less energy to walk upright than that of a chimp.

    I read that article in Scientific American too. Move on, unless you are a science fiction writer. Richard Dawkins is not spending time on this, but you put his name in your article so it will pop up in Google. That is my speculation.

  23. #23 stu of the Peak
    November 11, 2009

    The humanoid body plan is partly due to innate human arrogance and partly due to the lack of imagination in Hollywood creature fx departments*. I wonder if in many cases we would recognise sentient life at all simply because it’s so far removed from what we have come to know when looking for the signs of life. A spacecraft we were in might pass through an intelligent gas cloud a light year across that takes millennia to form a thought or move or communicate; it would be as unaware of our presence as we were of it’s.

    *I make an exception for the excellent burrowing Horta.

  24. #24 chris y
    November 11, 2009

    But I think the octopus layout is more practical in many ways, except that (IIRC) they have a brain which is a ring around the gut – not good.

    Quite a sophisticated brain though, by all accounts. Could pre-Cretaceous ammonites have evolved primate-like intelligence?

  25. #25 IanW
    November 11, 2009

    I guess Shermer doesn’t think Octopods are intelligent when he claims that “…only vertebrates actually developed it”?!

    Having said that, there appears to be a lot of “talking past” one-another going on here and it seems to me it’s because of very loose or non-existent definitions. Are Conway Morris, Dawkins, and Shermer all really talking about exactly the same thing?

    There’s a difference between the evolution of significant intelligence, of near-human intelligence, and of something like a human civilization.

    Is the problem that these three “definitions” are being used interchangeably?

    It seems to me that Conway Morris is perhaps taking the position that if our hands played a big part in our development, whereby the use of our hands and our socialization contributed to the growth of our brains, then if other organisms develop human-like civilization, it may well be because they followed a similar evolutionary path: bipedal, tool-using, highly social and so on. It doesn’t necessarily mean that he’s declaring that high intelligence cannot arise under other circumstances, but without having read exactly what he said, it’s hard to tell, and I
    don’t really read him very much these days.

    But look at it this way: primates have only been around for some 65 million years and evolved several species which developed intelligence that we’d consider human-like, whereas the dinosaurs were around for 160 million years or so and (unless, as some have pointed out, we’re arrogantly overlooking the evidence!) never developed anything quite like us.

    Perhaps that’s revealing.

  26. #26 Zach Hawkins
    November 11, 2009

    :(1) the human body shape really is the best shape for intelligence and sentience, and (2) convergence is so rampant throughout life on Earth that it very likely extends to life on other planets too. Point (2) may be reasonable, but point (1) seems less so.:
    Surely the whole aspect of learning is brought about by a body design that has all the things nesicery to learn ie the ability to manipulate items vie a source of control and acute senses.

  27. #27 Stagyar zil Doggo
    November 11, 2009

    Wouldn’t human like intelligence be of limited utility without a human like ability to manipulate tools? And since limbs optimized for tool manipulation are morphologically quite different from limbs optimized for locomotion, isn’t it at least more probably that any such hypothetical intelligent dinosaurs would be bipeds with forelimbs optimized for tool use?

    Of course, this doesn’t preclude a forelimb optimization quite different from human hands, or a very different body plan beyond the bipedality.

  28. #28 Mike Keesey
    November 11, 2009

    Conway Morris overlooks that convergence is indeed rampant when you subject the same morphology to the same selective pressures, but not at all when you try that with different starting points. For instance, sabre-toothed synapsids evolved again and again, but sabre-toothed sauropsids… diapsids with any kind of distinct caniniform teeth in the maxilla are almost limited to sphenodontines.

    Bit unfair to say “maxilla” and thereby disqualify heterodontosaurids, etc., especially since the point is to come up with convergences (i.e., analogies). The presence of a maxilla specifically indicates homology.

    Better way to make the point: osteichthyans have repeatedly evolved caniniform teeth, but no non-osteichthyan has.

  29. #29 Andreas Johansson
    November 11, 2009

    Better way to make the point: osteichthyans have repeatedly evolved caniniform teeth, but no non-osteichthyan has.

    Expressed that way it doesn’t seem like much of a point – most things with teeth are osteichthyans.

  30. #30 Jerzy
    November 11, 2009

    Brain size is not a good predictor of intelligence. Humans actually devote much of their cortex to image processing, and hummingbirds have possibly some of the smallest brains among tetrapods but show some of the more complex bird behaviours, eg. vocal mimicry…

    I think post-cretaceous dinosaurs would evolve primate-like intelligence.

    There is my pet theory. Some scientists rightly noticed, that although mutations are random, maximum complexity of organisms grows with time, and striking degeneration in animals is rare outside parasites.

    I would theorize that maximum intelligence grows with evolution time. That is, although average intelligence of animal kingdom may not change much, there is a subset of active animals where competition and Red Queen selection produces more and more intelligent forms.

    In this thinking, hypothetical evolution of dinosaurs would produce primate-like intelligent forms (and actually it did! Parrot and corvid intelligence is firmly above carnivores and within monkeys, and in few aspects within apes).

  31. #31 amphiox
    November 11, 2009

    #23:

    Budgetary constraints doubtless played an important role in the Hollywood penchant for humanoid aliens. For most of its history, and even today when we have so much CGI and animatronics, the cheapest way to get a whole lot of aliens on screen was to hire some cheap actors and slap some makeup on them.

  32. #32 amphiox
    November 11, 2009

    #27:
    The forelimb/hindlimb thing only applies if the base plan is a tetrapod. If you have more than two pairs of limbs to start with, you have a lot more options for evolving a tool-manipulating appendage. And even among tetrapod vertebrates we see things like prehensile tails, trunks, tongues, beaks, lips, etc that are used to dextrously manipulate the environment.

    As for the theropod dinosaurs, as I and others have previously pointed out, they already are bipedal, and already had forelimbs preadapted for grasping/manipulation.

  33. #33 Darren Naish
    November 11, 2009

    David (comment 22) says…

    I read that article in Scientific American too. Move on, unless you are a science fiction writer. Richard Dawkins is not spending time on this, but you put his name in your article so it will pop up in Google. That is my speculation.

    Yes, I’m sorry, but every now and again I choose to write posts that bring in the hits. You don’t need to criticise me for this: there is plenty more vacuous shite in the blogosphere that would benefit from your thoughts.

  34. #34 mr
    November 11, 2009

    I remember seeing a documentary that featured the dinosauroid when I was about 10 years old. I remember thinking it was stupid even then.

    I also really do not see why Dawkins is calling on this silliness and Conway Morris’s religiously motivated opinions. It just doesn’t seem consistent with any of his other positions to advocate any kind of inevitability for human-like intelligence and form. Did his argumentative streak just run away with him and he felt the need to find something to disagree with Shermer about?

  35. #35 Jim Thomerson
    November 11, 2009

    Some years back (90’s?) there was science fiction story in Analog. We went to the moon and found an abandoned dinosaur colony. The dinosaurs had made it to intelligence and wiped themselves out with atomic war.

  36. #36 Jude
    November 11, 2009

    Biologists squabbling over purely imaginary species bring new meaning to the word “idle.”

  37. #37 William Miller
    November 11, 2009

    @IanW: It goes deeper than that. There are at least four Cenozoic groups (odontocetes, primates, parrots, and corvids) which have evolved vastly higher intelligence than anything we know of from the Mesozoic. Perhaps, for some reason, it was not advantageous in the Mesozoic?

    Would a traditional deinonychosaur body shape allow throwing effectively? I could see them becoming sort of kangaroo shaped, to allow them to throw things with more effectiveness and have a longer reach, but they’d still look more or less dromaeosaurid.

    The truly humanlike facial features are just stupid, though I think we’d perceive anything with a rounded head and big brain as somewhat humanlike.

  38. #38 Dave H
    November 11, 2009

    “Biologists squabbling over purely imaginary species bring new meaning to the word “idle.””

    Hey Jude (sorry, couldn’t resist that)
    I don’t see any squabbling going on here: free-ranging discussion, thought experiments, speculation….yes, all of those. And we do it because we find it interesting. As for genuine squabbling over imaginary beings, we can leave that to the theologians.

    And haven’t you got anything better to do than take cheap shots at us? You sound pretty “idle” yourself.

  39. #39 Stagyar zil Doggo
    November 11, 2009

    Amphiox @32:

    The forelimb/hindlimb thing only applies if the base plan is a tetrapod.

    There were non-tetrapod dinosaurs?

    And even among tetrapod vertebrates we see things like prehensile tails, trunks, tongues, beaks, lips, etc that are used to dextrously manipulate the environment.

    It is possible that one of these non-limbs could evolve dexterity similar to human hands, but if you’re really serious about the intelligent manipulation of environment thing – you know, building A-bombs and stuff – you need at least two of the manipulator thingies. So, forelimbs are still the leading candidates.

    The first image in Darren’s post is unlikely, but the fellow with the long tail holding a stick in the third image doesn’t seem out of the realm of possibility to me.

    As for the theropod dinosaurs, as I and others have previously pointed out, they already are bipedal, and already had forelimbs preadapted for grasping/manipulation.

    Sorry, I didn’t read all the comments upthread carefully. But my argument is not limited to theropods. I’m proposing that any tetrapod which evolves a capability of building A-bombs is more likely to be a biped with dexterous forelimbs than not.

  40. #40 Jerzy
    November 11, 2009

    Film aliens are humanlike because producers feel that the thicker end of audience will not relate to non-humanlike creatures. Even a quadruped will be seen as “a dog”. This is what producers of the excellent “District 9″ said.

  41. #41 Laelaps
    November 11, 2009

    Bah. Don’t listen to the cranks (i.e. #22). I would have done the same thing, Darren, and when Dawkins says something stupid he should be fair game like anyone else.

    And you’re exactly right. The topics of contingency, convergence, teleology, etc. permeate questions of life elsewhere in the universe/how evolution might have gone if x did or did not happen. I would have thought that Dawkins would treat the topic more carefully after debating similar points with S.J. Gould for so many years, but I guess not. Farming out his response to E.O. Wilson and Simon Conway Morris was pretty lame.

    Anyway, I would have done the same thing as you, so don’t let the cranks get you down. As I said in my own brief comment I am using the Dinosauroid to talk about the issues of contingency, convergence, &c. in the conclusion of my book, and I think the fact that people keep citing the Dinosauroid is a good reason to keep questioning the assumptions behind it.

  42. #42 Dustman
    November 11, 2009

    jerzy @ #30 “In this thinking, hypothetical evolution of dinosaurs would produce primate-like intelligent forms (and actually it did! Parrot and corvid intelligence is firmly above carnivores and within monkeys, and in few aspects within apes).”

    Exactly.

    I have a number of corvid friends, I’ll tell them the nice things you said.

  43. #43 Tori
    November 11, 2009

    The whole concept of not-recognizing non-humanoid intellegence strikes me as a bit odd. We are clearly capable of recognizing intellegence in the other forms of life on this planet, be it humanoid or not.

    I think if you saw a hypothetical Avisapiens in the store, a majority of people would recognize that it was sentient. (Especially if you presume it uses tools.) The problem is the vast gap between our ability to recognize something’s intellegence, and our ability to be willfully blind to it. We are members of a species that is still coming to terms with the concept that all the members are equally sentient and gender and skin color doesn’t change that fact.

    Your brain would read Ms. Avisapiens in the grocery store as normal for a moment, before the pattern recognition kicked in. Then it would tag her as an ‘unknown/not of the tribe’ and that’s where it would very shortly get messy.

  44. #44 AD
    November 11, 2009

    Whoof, so many comments already. #25 makes some good points, especially about talking past eachother which seems to happen a lot on the controversial posts.
    I think it is obvious that if dinosaurs did evolve human intelligence, they would still look like dinosaurs and not scaly humans.
    I think hands are definitely necessary to best develop the tool use/brain development feedback.
    William Miller (#37) made a point about the Cenozoic not being a good time for intelligence. Perhaps there is something to that. When I imagine a dinosaur progressing past troodon-level intelligence I imagine something jumping around in trees eating fruit or nuts. A ready-made feast that doesn’t need hunting and killing might encourage large *social* groups, plus you don’t compete with velociraptors, tyrannosaurs and Utahraptors for kills: thus sacrificing or trading predatory adaptations for intelligence adaptations, (prior to development of very advanced intelligence with spears or something), would not leave you at a competitive disadvantage. Plus it seems like all terrestrial (ie excluding whales) animals with high-level intelligences passed through or still exist in a state of heavy dependence on angiosperm fruits (nuts, seeds)!

  45. #45 AD
    November 11, 2009

    OK OK i meant Mesozoic not being a good time for intelligence

  46. #46 een
    November 11, 2009

    With respect to tentacles, I always understood that they would have limitations as effective “limbs” for yer intelligent aliens. Although able to manipulate delicately, and pull, they can’t push. So building and vehicle manufacture and maintenance would be difficult with tentacles.

    I guess the aliens would have to design their buildings and engine compartments with lots of space around, giving enough room for a tentacle to pull from any direction.

  47. #47 AD
    November 11, 2009

    Marine realm always seems to be different- but perhaps echolocation, evolved to sense originally, played a similar role to hands in developing cetacean intelligence, while cooperation to hunt abundant marine resources played a similar role to he angiosperms on land? Ok nuff speculation..

  48. #48 Bret
    November 11, 2009

    It might just be my opinion, but I feel like humans use tools to make up for our inability to do certain things, like kill an animal, but you don’t need to learn to make a spear when you are an advanced hunting machine like a maniraptor.

  49. #49 AD
    November 11, 2009

    #48- Exactly. You do need intelligence to build a spear. Likewise, you DON’T need (high-level) intelligence to be an effective maniraptor. and indeed some hunting adaptations may work crossways to intelligence. One example might be strong jaw muscles constraining the size of the braincase because they wrap around it.

  50. #50 AD
    November 11, 2009

    Great post and topic.

  51. #51 Viergacht
    November 11, 2009

    Oh, I don’t know . . . I have a lingering affection for the dinosauroid.

    It seems equally silly and unimaginative to think dinosaurs with human-level intelligence would look just like big hornbills or parrots. Would it be possible for, say, an alien to look at a shewlike creature and imagine it could evolve into something that looked like us? No, if they’re using the same kind of justifications as the dinosaurid/avisapiens folks are, they’d picture an upright furry thing with a pointy snout and pants. You know, Mickey Mouse.

    My gut feeling is that an intelligent dino descendant wouldn’t look like a birdie OR a scaly human. Without being able to imagine what was going on in its environment for the past 65 million years, we couldn’t know which body shape was more likely, and it would almost certainly be far more divergent and interesting than either imaginary critter.

  52. #52 Nick Gardner
    November 11, 2009

    diapsids with any kind of distinct caniniform teeth in the maxilla are almost limited to sphenodontines

    Crocodyliforms?

  53. #53 Pierce R. Butler
    November 11, 2009

    Davd H @ # 18: It’s touching to see how the hypothetical dino-hominids in the painting above apparently share the same Flintstones-esque fashion sense …

    C’mon, not even a frumpy cavewife like Wilma F would match leopardskin with two shades of solid pink!

  54. #54 Azkyroth
    November 11, 2009

    in which case what other evidence of advanced intelligence could we expect to survive for 65+ million years?

    Synthetic plastics, if they got that far.

  55. #55 Nathan Myers
    November 11, 2009

    Jim Thomerson: That SF writer completely missed the boat by wiping out his sentient dinosaurs with a nuclear war; we would have found the isotopic traces. Far better to have had them divert an asteroid, either miscalculating the effect, or only accidentally provoking the collision. He would have been able to dine out on it for years after Chicxulub crater turned up.

    I find “Hermes to the Ages” by Frederick D. Gottfried, 1980, involving a dinosaur found on the moon in suspended animation. (Is that it?) It was in 1978 that Glen Penfield discovered the crater, and in 1980 that Luis Walter Alvarez proposed that a K-T-aged crater would certainly turn up, but ten years passed before the connection was established.

    Once we get the practical ability to divert asteroids, how long will pass before it gets used in anger?

  56. #56 John Scanlon FCD
    November 12, 2009

    #2:

    diapsids with any kind of distinct caniniform teeth in the maxilla are almost limited to sphenodontines

    What about agamids, David? – Is that your ‘almost’? Various crocodyliforms and dinosaurs (as others have noted) and also many snakes are strongly anisodont (or truly heterodont, with distinct crown morphologies as well as sharply distinct sizes), though the longest upper teeth are usually a few spaces back from the premaxilla-maxilla boundary, and indeed I can think of none that are really saber-toothed.

    #43:

    We are clearly capable of recognizing intellegence in the other forms of life on this planet, be it humanoid or not

    Speak for yourself! It’s only on the internet that no-one can tell you’re a dog. The Turing test is a great thing but only tells us about human-style verbal intelligence, and would not distinguish Alex the parrot from a machine. Meanwhile, vast numbers of humans have been taught to assume that animals have no ‘real’ emotions or thoughts, do not feel pain, and are no more than tools made for humans. Some, but possibly not all, are capable of recognising otherwise.

    #46:

    Although able to manipulate delicately, and pull, [tentacles] can’t push.

    Tentacles can be used to push, by straightening a curve, just like a snake’s body; while they may be less efficient than a limb with rigid bones, that can’t be a problem in principle, or tentacles couldn’t push their own weight away from the head. I thought the main disadvantage is that the lack of discrete joints makes proprioception an intractibly complex problem, hence octopods’ dependence on good binocular vision to know where their tentacles are at any moment. How sensitive is their sense of touch? I don’t recall ever seeing a ‘sensory octopunculus’ diagram based on brain mapping.

    Does anybody know why Dale Russell or his artist ever came up with a tailless dinosauroid? (‘Who ordered that?’) Except for that feature, it would be unexceptionable… and probably not newsworthy. In these days of parsimonious character optimization and the extant phylogenetic bracket, you couldn’t get there from maniraptorans without feathers, and certainly not with neither feathers nor bony tail.

  57. #57 llewelly
    November 12, 2009

    But then again, hypothetical intelligent deinonychosaurs with sickle-clawed feet and a jaw-full of sharp teeth might have had no need of flint tools in the way our hominid ancestors did, in which case what other evidence of advanced intelligence could we expect to survive for 65+ million years?

    Roads, if they built enough of them. Even relatively primitive roads are at least as durable as dino trackways. Modern asphalt and concrete roads could survive in identifiable form at much greater rates. Best of all – modern roads go almost everywhere on land, including many areas that will end up being good for preservation.

  58. #58 Tim Morris
    November 12, 2009

    Oh come now, we all know that a plausible dinosauroid exists, his name is Bigbird. I think the upright part is at least possible, but the whole human supremacy thing is silly. Mind you, upright birds are very intelligent, like penguins.

  59. #59 AD
    November 12, 2009

    Viergacht: Perhaps they would look like giant toadstools. There’s just no way of knowing.

  60. #60 Alan Dixon
    November 12, 2009

    Its obvious that the Humanoid body form is the most common for “High Intelligence”. Nearly all observed occupants of extra-terrestrial craft have Humanoid bodies. Proof or what! Some are indistinguishable from Humans.

  61. #61 Nathan Myers
    November 12, 2009

    On the subject of recognizing sentient life, I feel obliged to call your attention to this:

    Here we all sit with these huge brains we’re so proud of. Using them, we can throw a rock to knock down a bird. We can invent mathematics, and organza, and politics, and hard questions. Meanwhile, the lowly starfish creeps along the ocean floor, eon upon eon, nibbling, nibbling. It has no brain. It has no head to put one in.

    http://www.advogato.org/article/917.html

  62. #62 Dartian
    November 12, 2009

    Brian:

    The topics of contingency, convergence, teleology, etc. permeate questions of life elsewhere in the universe/how evolution might have gone if x did or did not happen.

    Teleology? Apart from Simon Conway Morris, are there still in the 21st century any notable evolutionary biologists who take teleological explanations seriously?

  63. #63 Darren Naish
    November 12, 2009

    Dartian: haven’t you just answered your own question? Brian’s point is that the invocation of the dinosauroid is a manifestation of teleology.

  64. #64 Dartian
    November 12, 2009

    Darren:

    the invocation of the dinosauroid is a manifestation of teleology

    No, not necessarily. Teleology implies design and a purpose (read: god/gods). Evolutionary convergence, even of the extreme kind that we’re talking about here, does not in itself automatically imply that; it is possible – in principle – that biological evolution, on Earth or elsewhere in the Universe, really does follow some yet-undiscovered ‘laws’ that inevitably lead to the eventual evolution of, say, superficially human-like organisms through non-supernatural means. In other words, you can be a logically consistent atheist and still take the ‘dinosauroid’ seriously. What I wanted to know is whether there are any other prominent contemporary biologists besides Conway Morris who subscribe to the out-and-out purposeful (i.e., teleological) version of convergent evolution.

  65. #65 Laelaps
    November 12, 2009

    Dartian; I’m not saying that teleology (in the mode of Conway Morris, Dale Russell, and perhaps others) is a valid concept, just that the idea often pops up in discussions about life elsewhere or how life on earth might have been different. As Darren said, the invocation of the Dinosauroid is a manifestation of teleological assumptions that I think should be addressed.

  66. #66 johannes
    November 12, 2009

    > diapsids with any kind of distinct caniniform teeth in the
    > maxilla are almost limited to sphenodontines.

    There were plenty of crocs with caniniform teeth, some of them true sabertooths, but I don’t know wether their canines (or pseudocanines?) were in the maxilla or in the premaxilla or in some other jaw bone.

  67. #67 Darren Naish
    November 12, 2009

    Dartian writes (comment 64)…

    the invocation of the dinosauroid is a manifestation of teleology

    No, not necessarily.

    I find it hard to think that it isn’t. We’re not, of course, dealing with a real animal and thus a natural instance of convergence: rather, the underlying assumption behind dinosauroids is ‘if these animals evolve big brains/intelligence etc., they would surely have evolved into a human-like shape, because that shape is best’. To restate, the core of the speculation is that the human shape is an inevitability – a goal – even though the lineage concerned is composed of long-tailed, horizontal-bodied, bird-like, cursorial animals that have followed a very different evolutionary path from hominoids. Are you going to tell me that this isn’t teleological?

  68. #68 Dartian
    November 12, 2009

    the underlying assumption behind dinosauroids […] is that the human shape is an inevitability

    But as far as I know, that particular underlying assumption has only been made by one particular individual, namely Simon Conway Morris. I was not disputing that he has teleological convictions. What I enquired was whether any other current professionally active biologist actually shares his extreme philosophical views. Has Dale Russell himself, for example, ever suggested that he does? Or was his dinosauroid only an elaborate yet not-to-be-taken-too-seriously thought experiment? (That is the impression I’ve always had, but I could be wrong.)

    Are you going to tell me that this isn’t teleological?

    Speaking generally and theoretically: No, it doesn’t necessarily need to be teleological (though in practice it usually is). To repeat: In principle, it is possible that the human body form really is universally optimal for a sentient organism, either here on Earth or anywhere else in the Universe. Now, I don’t believe that myself, and I don’t know any serious biologist who does that either (apart from SCM). As far as I know, there is not a shred of actual evidence that supports that view. But it is not an a priori impossible idea. That’s the point I was trying to make in comment #64 (apparently not very well).

    And I must say that I feel a bit uncomfortable discussing philosophical matters. Where is Allen Hazen?

  69. #69 Laelaps
    November 12, 2009

    Dartian; As far as I know Russell has never flatly stated “I have a teleological or goal-oriented view of evolution” but his latest book, Islands in the Cosmos supports the conclusion that he does. (I reviewed it here.)

    In the concluding chapters, especially, Russell casts life as striving upwards to meet potentials laid out for it by a “nonmaterial, creative Reason” outside the boundaries of what we can now detect in nature. Like Conway Morris (who wrote the foreword to Russell’s new book), Russell appears to have a view of evolution heavily informed by his theistic beliefs in which humans (or at least humanoids) must have some kind of privileged status. There is a scientific argument to be had about convergence, optimality, contingency, &c. but from my reading thought experiments like the Dinosauroid simply use scientific language to back up a point taken on faith, namely that humans are exceptional and therefore somehow inevitable.

    As far as I am aware no real explanation has been given by Russell, Conway Morris, or anyone else as to why the Dinosauroid is “optimal”; it is simply enough to say that it is because it looks like us. That, I think, really pinpoints that the Dinosauroid is more about belief in human inevitability based on faith rather than science.

  70. #70 Darren Naish
    November 12, 2009

    I see where you are coming from, Dartian. As for the underlying philosophy behind Russell’s dinosauroid, a few choice quotes…

    “We [Russell & Seguin] evaluated the adaptive meaning of the human form and reassessed the proposition that there is a vanishingly small probability of it being a target for natural selective pressures” (Russell 1987, p. 125).

    “The models were not made with the intent to offend anyone’s philosophical outlook and can be interpreted as an argument that the humanoid form may be a special (nonrandom) solution to the biophysical problems posed by intelligence” (Russell 1987, p. 128).

    “[The dinosauroid] implies that the dinosauroid-humanoid form may have a nonnegligable probability of appearing as a consequence of natural selection within the biospheres of earthlike planets. And that there may be something more to study in the biophysical configuration of man” (Russell 1987, p. 130).

    In the section of Psihoyos & Knoebber (1994) on the dinosauroid, Russell is quoted as beginning with “If you look at mammal skeletons, they are beautiful things”. He continues: “They have so much complexity compared to dinosaurs. Dinosaur skeletons are so crude, by comparison – they’re wonderful in the proper perspective. But my acquaintance with the dinosaurian world just makes me marvel at the modern world. Having studied dinosaurs for thirty years, more or less, I just look at the modern world like a miracle – it is so interesting and so rich, and man is the same way, because – How can I say this? Man is extraordinarily successful” (pp. 251-252).

  71. #71 Dartian
    November 12, 2009

    Brian and Darren, thanks for the information on Dale Russell!

  72. #72 Laelaps
    November 12, 2009

    It may also be worth looking at what Conway Morris had to say about the Dinosauroid in the Horizon documentary “My Pet Dinosaur.”

    What I found most interesting about that portion of the show was that Conway Morris was not proposing a Dinosauroid in place of Homo sapiens. Instead the implication is that the Dinosauroid would have evolved alongside hominins and we would inhabit that earth together. It would seem that, for Conway Morris anyway, not only was the humanoid form inevitable but that our precise species was, as well. Now that’s some hardcore teleology. :)

  73. #73 Darren Naish
    November 12, 2009

    Wow, thanks for the link Brian. I missed that documentary when it was shown and am kind of glad that I did (and I say this as someone who’s spent far too much time thinking about speculative zoology). Just want to say that the two people featured at the very end of the clip were Brent Breithaupt and Don Lessem. I’m sure everyone can already recognise Phil Currie.

  74. #74 Jesse
    November 12, 2009

    Does anyone here remember the part of Stephen Baxter’s book “Evolution” where he proposes an intelligent dino back in the Jurassic?

    I thought the interesting thing he mentions there is twofold: intelligence evolving in a social predator species, and the intelligent dinos being wiped out by the extinction of the “herd” animal, the diplodocus, which served a function similar to elephants.

    He speculated that the reason we don’t see any evidence of them is twofold: the large brained skulls were (relative to primates) thin and delicate, and there weren’t enough of the creatures that any happened to die in a fossil-friendly area (he makes the same case for other fictional ideas he has, such as air whales — if they all die on mountaintops and such there wouldn’t be any fossils). The other issue was the tools — a creature that makes stuff out of wood won’t have anything that lasts long enough to notice.

    Another thing: it is interesting to ask oneself how any creature can manipulate its environment in certain ways without fire. For example, building anything at all out of metal requires some way to smelt it. You need fire for that, even if you are extracting bog iron. Underwater intelligence would be very nearly precluded from inventing metals, unless they lived at the bottom of a deep ocean and could hang around lava vents, but even so…

    If dinosaurs really did evolve intelligence and built an industrial civilization, we would see evidence of use of things like oil or coal, perhaps, in the isotopic content of the carbons, would we not? While most artifacts would likely not last 65+ million years, something like a cut gem would. If the population of said intelligent dinos was in the billions, a few must have died in some fossil-friendly situation, and with their artifacts on them.

    As to recognizing intelligence, (I’ll tip my hat to Baxter here as well) if you had a creature that was an amorphous blob, stuff like counting might not be as important to you… so things like number sequences would only matter to a discrete creature and probably one with digits or something.

    I don’t think intelligence in a predator is precluded by the ability to hunt for food — a social predator species can get by without having the biggest, baddest teeth and claws — see wolves, dogs, and even pirhanas. Wolves hunt co-operatively and aren’t necessarily the hardest biters with the biggest teeth. And they are pretty smart, as these things go.

  75. #75 David Marjanović
    November 12, 2009

    Completely forgot to complain about the plantigrade feet in the first picture. That’s even dumber than all the rest together.

    (And those two convenient holes in the grass cover… what an unsubtle artist.)

    octopii

    Everything, anything, except that! :-)

    Bit unfair to say “maxilla” and thereby disqualify heterodontosaurids, etc., especially since the point is to come up with convergences (i.e., analogies).

    OK. In that case we get heterodontosaurids and diverse crocodylomorphs, but I think that’s it, and I’m not even aware of a saber-toothed crocodylomorph.

    The idea has been floated around that caniniform teeth require a completely akinetic skull. Maybe that’s what’s going on here: given the same selective pressures, osteichthyans with a completely akinetic skull grow long caniniforms, while others turn the entire maxilla into a caniniform region (tyrannosaurids for instance).

    The presence of a maxilla specifically indicates homology.

    Not secondary homology. I can’t find a way to optimize the caniniform maxillary teeth of whatcheeriids as homologous with mine.

    There are at least four Cenozoic groups (odontocetes, primates, parrots, and corvids) which have evolved vastly higher intelligence than anything we know of from the Mesozoic.

    How would we recognize that sort of intelligence in the fossil record?

    you need at least two of the manipulator thingies.

    Or a colleague. :-)

    With respect to tentacles, I always understood that they would have limitations as effective “limbs” for yer intelligent aliens. Although able to manipulate delicately, and pull, they can’t push.

    1) Just wait till they invent the lever. After all, that’s how we push, only our levers (bones) are inbuilt — muscles can only pull.
    2) Alternatively, imagine a hydrostatic skeleton. You can push with your tongue.

    What about agamids, David? – Is that your ‘almost’?

    I suppose so. Though, in reality, my neontological ignorance is showing.

    In snakes, are extra-long teeth ever not involved in poison injection?

    http://www.advogato.org/article/917.html

    advogato.org cannot be found.

    Teleology implies design and a purpose (read: god/gods).

    Really? That’s not how I’ve interpreted the term so far. I thought it only implies that the endpoint (telos) can be predicted in advance, even if it’s due to impersonal laws like, say, Marx’s pseudoscientific theory of history.

    In the section of Psihoyos & Knoebber (1994) on the dinosauroid, Russell is quoted as beginning with “If you look at mammal skeletons, they are beautiful things”. He continues: “They have so much complexity compared to dinosaurs. Dinosaur skeletons are so crude, by comparison – they’re wonderful in the proper perspective. But my acquaintance with the dinosaurian world just makes me marvel at the modern world. Having studied dinosaurs for thirty years, more or less, I just look at the modern world like a miracle – it is so interesting and so rich

    :-O :-o :-O :-o

    What a moron. Compare an elephant or a giraffe or both to Giraffatitan, and weep that the latter is extinct. Compare a lion to Tyrannosaurus, and… just… laugh. The poor lion has conical canines for crying out loud. I could go on for hours.

    Wolves hunt co-operatively and aren’t necessarily the hardest biters with the biggest teeth.

    Indeed. A wolf pack needs hours to kill a bison.

  76. #76 Sven DiMilo
    November 12, 2009

    Alternatively, imagine a hydrostatic skeleton. You can push with your tongue.

    And yet another alternative is a hydraulic extensor system, as in spiders and (totally different) echinoderms.

    In snakes, are extra-long teeth ever not involved in poison injection?

    Heterodon and Xenodon have toad-popping elongated maxillary teeth. Of course they’re also slightly venomous.

  77. #77 Zach Miller
    November 12, 2009

    Anyone remember the awful “Ultimate Dinosaur” book? Half of it was a piece of sci-fi fiction that again invoked the dinosauroid, but replace “dinosaur” with “mosasaur” and you’ll get the idea. Rubbish, absolute rubbish.

    I did like the illustration by Wayne Douglas Barlow, though.

  78. #78 William Miller
    November 12, 2009

    >>How would we recognize that sort of intelligence in the fossil record?

    Well, OK… but nothing Mesozoic has a big brain. Even troodontids are impressive for the Mesozoic, but don’t hold a candle to a lot of Cenozoic things – much less parrots, corvids, dolphins, and primates, which all have comparably high encephalization quotients. Since those groups evolved high intelligence independently, I think it’s reasonable to suggest that encephalization quotient is a decent analogue for intelligence, in vertebrates at least.

    And it’s more than just those groups. Adjusted for body size, tyrannosaurs were smaller-brained than tigers, sauropods were smaller-brained than elephants. Are there any ideas why this is?

  79. #79 Jim Thomerson
    November 12, 2009

    We are constrained in our thinking by knowing that the human form is one which can build a technological civilization. We don’t know that this is true of any other form, we can only speculate. We end up criticizing our speculation of insectoids, or whatever, by arguing that they are not human-like in one way or another.

    I can’t picture an technological civilization built by an aquatic creature. It seems to me that access to fire is a required prerequisite.

  80. #80 David Marjanović
    November 12, 2009

    Adjusted for body size, tyrannosaurs were smaller-brained than tigers, sauropods were smaller-brained than elephants. Are there any ideas why this is?

    Phylogenetic inertia, with mammals coming from a large-headed shrew-shaped ancestor that dinosaurs lack?

    Also, in mammals, the brain/body size ratio increases with size – chimps, humans, dolphins, elephants, and sperm whales are all at the upper end of the range of brain sizes expected for their body size, but not beyond.

  81. #81 Stagyar zil Doggo
    November 12, 2009
    you need at least two of the manipulator thingies.

    Or a colleague. :-)

    That thought did occur to me. Such creatures’ manipulative dexterity would be limited by the data rate at which they are able to communicate fine details of limb position, force and movement intent to each other.

    Think of the co-ordination between limbs required even to say, flake flint, or bind a stone to a wooden handle using twine. Doing these with only one hand along with similarly constrained colleagues is probably possible, but would take much longer even if you developed a communication protocol for it. Though both tasks and anatomy in this thought experiment are human, I suspect the limitation carries over to all dexterous tasks and “limbs”.

    A creature of this type, able to communicate at a data rate high enough to achieve human like dexterity is I suspect, far more unlikely than an intelligent tetrapod with two dexterous limbs.

  82. #82 Carlos
    November 12, 2009

    Why the hell people focus more on sentient dinosaurs beats me. That design should really be more apropriate for a notosuchian.

    And where did the sapient pterosaurs go? Viergacht’s is the only one I’ve seen so far that is convincing!

  83. #83 Allen Hazen
    November 12, 2009

    Re: Dartian, comment #68
    I’m here. Teleological thinking is alive and well in biology: anyone who talks about the “function” of an organ or whatever is thinking teleologically: the function is not necessarily what something DOES, but what it’s FOR. (Aposematic coloring of butterflies has the function of telling birds not to eat them, even if dumb birds sometimes do. Weight makes mountain goats fall, but thatis not its function.) … Of course we have a foundational story about natural selection to explain our use of teleology, so we can say our use of teleological concepts doesn’t commit us to “intelligent designer” creationism. (But in practice we don’t always work out the details: we can — good thing! — identify functions without having to run longterm ecological experiments to identify selective pressures. We do that sometimes– as in the recent (last year or so?) verification that the “horns” of American horned toads have the function of deterring shrike predation– but we don’t always have to.)

    I don’t know Conway Morris’s detailed views (I’ve only read his early book, which seemed like a — deserved — rejoinder to Stephen J. Gould’s “Wonderful Life”). He may be a theist, and he sometimes thinks teleologically. I have no idea whether these are connected in his case. (I think it’s clear that you can think teleologically, at least to a degree, without being a theist. In the other direction, look at Descartes, who was a theist but said in his “Meditations” that since God was infinitely intelligent we finite beings couldn’t work out WHY he did things, and that this showed the worthlessness of teleology in matters of natural science.)

    (Mind you, I also think you can say some good things about orthogenesis, so maybe my opinions should be taken with salt.)

  84. #84 Jerzy
    November 12, 2009

    @Dustman
    You may be serious or joking, in either case read excellent book “Mind of the raven”. I particulary liked descriptions how a group of ravens ALWAYS outsmarts a group of wolves to steal prey.

    Just some comments:
    – cephalopods actually normally manipulate tentacles by bending them in few places, creating an equivalent of joints;
    – tetrapod body plan is actually very unsuitable for a land animal. Most of the weight hangs in thin air between front and hind limbs, straining the flexible backbone contaning unossified discs. When the poor creature uses front legs, the hind ones are unbalanced. Evolutionary, a hexapod is better designed.
    – right point that looking at the fossil, we would have zero indication that dolphins are more clever than elephantfish and monkeys have more complicated behaviour than t-rex.
    – WHY OH WHY nobody thought that underwater animal can control fire on the water surface? Would a sapient dolphin wonder how humans use liquids outside water?

  85. #85 AD
    November 12, 2009

    “Phylogenetic inertia, with mammals coming from a large-headed shrew-shaped ancestor that dinosaurs lack?”

    Well, I don’t see why brain size follows head-size- just look at T-Rex with its massive powerfully built skull. Note that it would seem to be just as easy for early Cenozoic large mammals to develop large body size without concomitant increase in brain size- as seen in Pantodonts and other early Cenozoic mammals. Nevertheless I would be willing to hazard these are still above a dinosaurian encephalization average, and overall there seems there is something about the mammalian bauplan that requires a relatively larger brain, even in early forms, and so big-brain phylogenetic inertia (or in-built requirements) might be an explanation for the typically larger brains of mammals.

    David, you bring up another point- the much larger size of dinosaur herbivores, and the greater deadliness of dinosaur carnovores, perhaps even adjusting for size. One could argue that when dinosaurs evolved in the Triassic they were probably average to above average intelligence compared to the other reptiles. Their subsequent evolution found success mostly in adaptations other than brain size or cleverness, such as large body size, agile and active warm-bloodedness, the use of a crop to break down tough conifers, or deadly weaponry of horns, teeth, and claws. (One could make the same argument about why sharks have never evolved high-level encephalization or intelligence, although some are on the high end for fish). Whereas mammals don’t seem to be as susceptible to the evolution of very large body size, at least on land, but there does seem to be a trend towards larger brain size for mammalian faunal assemblages overall over the Cenozoic. These were the pathways of evolution most exploitable by mammals given the initial conditions.

    I still like the idea that angiosperms, either directly through fruits or indirectly through provisioning of easier-to-digest leaves or fomenting a radiation of tasty insect diversity, played a key role in allowing high-level encephalization and intelligence to arise in birds and mammals. Come to think of it I think it’s been argued elsewhere that fruiting trees, at least, played a key role in developing the large group size and concomitant social competition aspect of primates, for one example, although I have no idea where.

    Ant diversity, beetle diversity, perhaps high encephalization in mammals and birds- what hasn’t the angiosperm revolution accomplished?

  86. #86 AC
    November 13, 2009

    I think Conway Morris’ perspective on this issue, like that of Dale Russell is badly flawed. Regardless of what a persons religous ideas are, the whole idea of optimal design and progress towards intelligence is mistaken. Increasing complexity (as Dawkins advocates) is not the same as progressive evolution.

    Specifically organisms don’t seem to have an open playing field by which anything is possible- there are developmental and phylogenetic constraints which restrict what variation can arise and then be selected for. I don’t see any undertsanding of these constraints in the conception of a “dinosauroid”. We only need to look to the relatively conservative body plans of modern birds to see that the suspiciously human charcteristics of the “dinosauroid” is unlikely at best, if not simply impossible, for natural selection to achieved from a Troodontid ancestor.

  87. #87 Dartian
    November 13, 2009

    Really? That’s not how I’ve interpreted the term so far. I thought it only implies that the endpoint (telos) can be predicted in advance, even if it’s due to impersonal laws

    David (and Allen): Regarding the exact meaning of ‘teleology’, I’ve been following the Merriam-Webster definition:

    Etymology: New Latin teleologia, from Greek tele-, telos end, purpose + -logia -logy[…]
    1 a : the study of evidences of design in nature b : a doctrine (as in vitalism) that ends are immanent in nature c : a doctrine explaining phenomena by final causes
    2 : the fact or character attributed to nature or natural processes of being directed toward an end or shaped by a purpose
    3 : the use of design or purpose as an explanation of natural phenomena

    ‘Design’, ‘purpose’, ‘immanent’, ‘final causes'; the way I interpret it, those terms are not meant to be taken figuratively, but literally*. Hence, I can’t see how you can have real teleology without truly believing in divine influence of some sort. Design automatically implies a designer (who, surely, in this case would have to be a ‘god’). Is this not so?

    * Notice, for example, that 3 says ‘design’, not ‘what looks like design’.

  88. #88 Andreas Johansson
    November 13, 2009

    Also, in mammals, the brain/body size ratio increases with size – chimps, humans, dolphins, elephants, and sperm whales are all at the upper end of the range of brain sizes expected for their body size, but not beyond.

    How can chimps and humans both be at the upper end of the range? Adult size overlaps considerably, adult brain size only in severely pathological cases.

  89. #89 Dartian
    November 13, 2009

    The guy who wrote this upthread:

    you put his name in your article so it will pop up in Google

    Yes, and a very successful strategy it was too.

    Coming soon: Tet Zoo post titled ‘Richard Dawkins and the Neotropical bufonid radiation’ and ‘The Tet Zoo tour of Libya (part III): fossils, Colonel Gaddafi, and Richard Dawkins’.

  90. #90 johannes
    November 13, 2009

    > and I’m not even aware of a saber-toothed crocodylomorph

    David,
    what about *Cynodontosuchus*?

  91. #91 David Marjanović
    November 13, 2009

    there does seem to be a trend towards larger brain size for mammalian faunal assemblages overall over the Cenozoic.

    This (“Marsh’s law”) should be tested. I wonder if it would fare any better than the alleged universal trend for size increase (“Cope’s rule”, never mind Depéret who stated it much more strongly).

    Regarding the exact meaning of ‘teleology’, I’ve been following the Merriam-Webster definition:

    What about 1 b?

    Also, 1 a says “evidences”, a term that only Christian apologists use anymore.

    Adult size overlaps considerably

    Really? I’ll try to find out, but I won’t see the paper I have in mind before close to Christmas.

    what about *Cynodontosuchus*?

    Good point, I’ll try to look it up (which turned out to be surprisingly difficult last time I tried).

  92. #92 Dartian
    November 13, 2009

    David:

    What about 1 b?

    According to that sub-definition, teleology could also be interpreted non-supernaturally, but historically it usually hasn’t been interpreted that way. The concept of ‘immanence’ has intimate theological connotations. And the ‘vitalism’ referred to in 1 b harks back to Henri Bergson’s élan vital, which, as far an explanatory principle goes, is hardly any better than explicit religiosity.

    Also, 1 a says “evidences”, a term that only Christian apologists use anymore.

    Yes, that’s kind of the point, isn’t it? The doctrine of teleology is so hopelessly intermingled with religious (and specifically Christian) philosophy, and it carries so much un-scientific (or even anti-scientific) historical baggage that, in my opinion, biology would be better off to abandon this concept altogether.

  93. #93 Nikola Popovic
    November 13, 2009

    “Humanoid” and “dinosaur(s)” happens to be my least favorite combination of words.

  94. #94 Jesse
    November 13, 2009

    @Jerzy (84)

    I think the problem with manipulating fire at the surface is that you need something that will burn there — like a floating lake of oil or whatever — and then, on top of that, a way to light it.

    That’s an awful lot more steps than watching lightning set something aflame. Also, our land- and air-based ancestors could see fire all around them in volcanoes and forest fires.

    Underwater creatures would not have that. Not saying they couldn’t be really smart, just that technologically they would be limited.

    Harry Harrison in “West of Eden” proposed a bit more realistic evolution of coastal-based dinosaurs developing intelligence, a civilization and even techniques of biological manipulation — but no fire.

    @David (75) – yeah but wolves hunt co-operatively for other things besides bison, as do other predators. They go for the weak and sick in any case. As the old Native saying goes, “The wolf keeps the caribou strong.”

    The feedback loop there is interesting. Stronger, bigger caribou. That means healthier, and ultimately better to eat. Which means even though wolves have to work harder at it, the ones they do get are better for them, in a nutritional sense, you know? As caribou get smarter to avoid wolf packs, and wolves need to get smarter to create more complicated hunting strategies, I could see intelligence developing over time. Especially if the prey animals were putting additional selective pressure on the predators.

  95. #95 xenithrys
    November 13, 2009

    Dave @ 12 might be right. Look at it this way: How much evidence of Homo sapiens‘ intelligence and culture will be available to paleontologists in 64 million years from now? The concrete and steel might last a few thousand years, plastic and glass perhaps rather longer. I’d guess the main evidence in the fossil record will be the mass extinction we’re causing, which might look similar to the one at the K-T boundary.

  96. #96 Nick Gardner
    November 13, 2009

    OK. In that case we get heterodontosaurids and diverse crocodylomorphs, but I think that’s it, and I’m not even aware of a saber-toothed crocodylomorph.

    The idea has been floated around that caniniform teeth require a completely akinetic skull. Maybe that’s what’s going on here: given the same selective pressures, osteichthyans with a completely akinetic skull grow long caniniforms, while others turn the entire maxilla into a caniniform region (tyrannosaurids for instance).

    I think it depends on what we are using to define as ‘caniniform’, I presumed we were talking about something like the ‘ziphodont’ condition. There is a review paper on dentition in notosuchians/ziphosuchians* but I think it makes the situation more complex than needed by introducing some new terms that as far as I can tell, the authors don’t even continue to use in their more recent papers. Many crocodyliforms (and stem-crocodiles in general) have blade-like teeth, and also some have the more rounded but still carinated teeth. Dental morphology is highly diverse within stem-crocodiles as a whole, and there is no really good review of it all as far as I am aware of. There is probably also a lot of convergence between groups (after all, notosuchians/ziphosuchians* might not even be monophyletic– Jouve 2009).

    * a.k.a. ‘gondwanasuchians’, ‘notosuchiforms’, ‘notosuchimorphs’, ‘peirosauriforms’, ‘peirosauromorphs’, ‘terriasuchians’, etc. Ironically, all of these potentially synonymous names were coined in the same paper (Carvalho et al. 2004).

    Before I went on my blogging hiatus this semester, I tried to tackle some of the problems of this here:
    http://whyihatetheropods.blogspot.com/2009/08/knowing-your-crocodyliforms.html

    I tend to play with those names pretty loosely myself. I almost always use Neosuchia to indicate a clade of taxa closer to modern crocs than to Notosuchus (ala Sereno). When I speak of notosuchians, I’m typically referring to all notosuchians except sebecosuchians (baurusuchids and sebecids), this usage is obviously paraphyletic (and maybe even polyphyletic if Jouve’s topology is true). I realize this isn’t anywhere near an ideal solution, nor do I even want it to be a solution.

    Any thoughts or answers to this?

  97. #97 Jim Thomerson
    November 13, 2009

    You might take a look at Ernst Mayer’s thoughts on teleology.

    http://www.clt.astate.edu/aromero/aristotle.teleology.pdf

  98. #98 David Marjanović
    November 13, 2009

    I think it depends on what we are using to define as ‘caniniform’, I presumed we were talking about something like the ‘ziphodont’ condition.

    I mean one or two teeth that are markedly bigger than all others on that bone; if there’s a gradual decrease to normal in tooth size on both sides of the longest tooth, that’s a “caniniform region” (best seen in some varanopids such as Aerosaurus, but also present in, say, Eryops… and in tyrannosaurids there’s no row of equal-sized teeth, so the entire maxillary dentition could be said to be a caniniform region).

    When there’s one caniniform tooth that is extremely long and xiphodont*, that’s a saber tooth.

    * I think this word comes from Greek xiphias = sword, like the xiphoid/xiphisternal process of the sternum; if so, the spelling with z must be an error that can only be explained by English pronunciation. Does someone know better?

  99. #99 Chris M.
    November 13, 2009

    On the brain-size front, as to why the Cenozoic is apparently smarter, there are a couple of things that have occurred to me.

    One, evolutionary inertia, but in the sense of having an established genetic code base for building neural circuits. There’s a definite increase from invertebrates to mammals, in the basic chemical complexity of what neurons are doing in the brain, but I don’t know much myself about the other major groups. I’d love to see some good work looking at human/mammal brains compared to birds, to contrast the neural development paths. Regardless, there’s a big thing in common there.

    Could be that long, continuous run of warm-bloodedness in the lineages for a hundred some million years. When you’re running a body at nearly full tilt all the time, a little bit of extra energy devoted to neural processing carries a much smaller relative cost, compared to a cold-blooded animal. That, and it lets you target that high activity more efficiently. It’s a complicated but relatively less metabolically costly way to improve performance than, say, running the metabolism even faster.

    Anyway, intelligence clearly wasn’t out of the question for descendants of dinosaurs, as the birds show nicely, but it’s pretty ridiculous to think that something with a nice, bipedal design with free arms for manipulation would automatically head back toward us. Humans have only recently arrived at that point ourselves!

  100. #100 Jerzy
    November 13, 2009

    @Jesse (94)
    Water creatures could simply smelt metals on platforms or islands exposed on water surface. Humans have no problem with making water-filled test tubes, baths, pools, canals etc.

    But underwater creatures would find many other things much easier to develop. Electricity eg. would be well known natural force from the time immemorial. Many water animals sense electric activity of muscles and nerves of prey. Perhaps advanced underwater sapients would much earlier and easier develop kinds of interfaces where nervous system directly controls machinery. It might be actually their dominant form of operating machinery.

    Artificial light is also obvious underwater – although domesticated fluorescent invertebrates serving as lamps would be unusual for us.

    Chemistry is also much easier when you smell compounds underwater. Durable construction materials could be made from non-soluble resins instead of metal alloys, as the latter corrode underwater.

    Cultural exchange and globalization is also easy in Earth-like ocean where currents provide free transport routes. Etc. Etc.

    You see how humanocentric is really our view of technology.

  101. #101 Nick Gardner
    November 13, 2009

    I mean one or two teeth that are markedly bigger than all others on that bone; if there’s a gradual decrease to normal in tooth size on both sides of the longest tooth, that’s a “caniniform region” (best seen in some varanopids such as Aerosaurus, but also present in, say, Eryops… and in tyrannosaurids there’s no row of equal-sized teeth, so the entire maxillary dentition could be said to be a caniniform region).

    If that’s what you mean, then you should look at the tooth rows of crocodyliforms like sebecosuchians (great photograph of Baurusuchus here: http://www.faperj.br/images/Baurusuchus/fossil5.jpg ; see also my blog when I discussed a recent paper reviewing some Cenozoic forms http://whyihatetheropods.blogspot.com/2009/08/old-news-but-lot-of-new-names-for.html there are figures of the ‘sebecid’ Barinasuchus from the paper describing it) and peirosaurids.

    Darren actually briefly discussed sebecosuchians here: http://scienceblogs.com/tetrapodzoology/2007/03/move_over_theropoda_sebecosuch.php Though I often forget about this post, to be honest. It is a bit odd that there is a picture of the skull of Uberabasuchus in a discussion of sebecosuchians, but then maybe it makes sense if your topology is that of Larsson and Sues (2007) with ‘Sebecia’ including peirosaurids and oddly enough, Stolokrosuchus.

    I suppose the buzz over crocodyliforms is only going to get more noisy soon as the descriptions of Sereno et al.’s crocs from the Cretaceous Sahara begin to hit the press *cough* “Boar croc” *cough*. Though, those in the know, will be anticipating others =)

    On a much earlier part of the tree, I’ve got to get my hands on some refs concerning Barbarenasuchus

  102. #102 Jerzy
    November 13, 2009

    Actually, prior to farming revolution, only durable traces of intelligence are few figurines and stone tools. Which assumes that intelligence must make tools from chipped stone instead of eg. hardened wood and develop visual art.

    About brain size. Despite larger brain, I see that non-primate mammals show no greater behavioral complexity compared to birds. You have territories, mating fights etc. Because many people assume that dinosaur behaviour was like birds’ I wonder if mammals are really more intelligent than dinosaurs.

  103. #103 andy
    November 13, 2009

    I have to wonder whether human-level intelligence is a strong attractor in the course of evolution. Seems to me that there may be many factors to select against it quite strongly, particularly the energy requirements for powering the brain, and even the typical intelligent species seem to get by without going the whole way to “runaway technology” (or whatever it is we’ve got).

    Leaves the question of what the driving factors behind the evolution of intelligence in humans were: is human intelligence another weird “display structure”, like peacock tails or various crests, bright colors, etc. which came about more through interactions within the species rather than through direct pressure from the environment.

    Then again, I’m not a biologist, so for all I know these questions are nonsense.

  104. #104 Ad
    November 13, 2009

    Jerzy- a few quick thoughts- I think you have convergent evolution for advanced cognition in birds and mammals- birds do it differently- and I think people have looked at homologies between bird and dinosaur brains, as far as we can do that, and concluded that dinosaurs were not as advanced in general. Although to use a totally uncitable reference I remember some scientist on a Discovery channel show talking about troodon having the intelligence of about a modern raptor- which might not be too bad, seeing as these animals can be trained to be fearsome and obedient hunters (gratuitous cool youtube video: http://www.youtube.com/watch?v=T4_4d_99ApE). But to be rigorous one would have to dig out some references on avian dinosaur/non-avian dinosaur braincase comparisons.

  105. #105 AD
    November 13, 2009

    Just to continue the comment thread that will not die: some references for the comments I made earlier about the effect of the angiosperm radiation on:

    beetle diversity:
    https://www.sciencemag.org/cgi/content/full/281/5376/555
    ant diversity:
    http://www.sciencemag.org/cgi/content/full/312/5770/101
    and the evolution of (highly encephalized) birds, bats and primates:
    http://www3.interscience.wiley.com/journal/110487778/abstract
    I’m not sure whether or not I had heard it before, but nevertheless a google search seems to show that the last idea is a legitimate hypothesis/theory about the origins of primates. Perhaps it could be extended to also explain the origins of cognitively advanced birds as well, which often mimic primates in food sources and social group-living?

  106. #106 ad
    November 13, 2009

    I think SciBlog denied my comment because of the internet addresses (whoops, sry Darren), but here is another try

    Just to continue the comment thread that will not die: some references for the comments I made earlier about the effect of the angiosperm radiation on:

    beetle diversity:
    http://www.sciencemag.org/cgi/content/full/281/5376/555
    ant diversity:
    http://www.sciencemag.org/cgi/content/full/312/5770/101
    and the evolution of (highly encephalized) birds, bats and primates:
    www3.interscience.wiley.com/journal/110487778/abstract
    I’m not sure whether or not I had heard it before, but nevertheless a google search seems to show that the last idea is a legitimate hypothesis/theory about the origins of primates. Perhaps it could be extended to also explain the origins of cognitively advanced birds as well, which often mimic primates in food sources and social group-living?

  107. #107 Monado, FCD
    November 13, 2009

    An intelligent dinosaur would not have broad, flattened shoulders like a gibbon, but narrow ones like a cat or a parrot. Far too many people think that intelligence equals upright posture equals human shoulders.

  108. #108 Allen Hazen
    November 13, 2009

    Re: Dartian (at comment #87)–
    What I was thinking of, as “teleological thinking,” was pretty much what (3) in Webster’s says. ((2) is a different usage, related to it. (3) describes someone who says “the heart is FOR pumping blood”; if they are right and that IS the function of the heart, (2) is the fact they are describing.)

    Depending on exactly what you mean by “final cause” (people have been trying to interpret what Aristotle meant for over 2,000 years and STILL haven’t reached agreement!), (1c) may be close to the same as (3): when one speaks of Aristotle’s doctrine of “four causes,” the word “cause” isn’t really appropriate: what we moderns mean by “cause” is closest to Aristotle’s “efficient cause,” and the other three are things it would be very un-idiomatic to call causes in modern English. “Four becauses,” or “for kinds of explanatorily relevant fact” would be better (but who are we to argue with tradition?). “Final cause” is rouglhy “purpose” or “function”.

    Even (1b) can be taken in different ways. “Immanent” is a really muddy piece of philosophical jargon, and is, I think, understood in more and less theological ways. Calling purpose “immanent,” though, if it means anything, means you DON’T think the purpose is a consciously held intention by a thinking and conscous agent. (Some would say that it’s a typical dodge of modern religious thinking to go vague if anyone presses you, and I suspect that sometimes this is what “immanent” is about: one doesn’t feel that it is quite intellectually respectable any more to believe LITERALLY in, say, divine purpose, but one still wants to believe in it somehow: so one says the purpose is immanent.)

    But if I had anything important to say, I guess it was just that teleological concepts (in senses (3), (2), possibly (1c) and maybe even, on some interpretations, (1b)) are independent of theism, and don’t commit you to teleology in sense (1a).

    B.t.w.: My experience (reading student essays when I was trying to teach philosophy to undergraduates) is that Dictionaries are a week reed when it comes to philosophical discussion: dictionary definitions are VERY often approximate, in ways that may not matter to a foreigner learning the language or a native encountering a new word in reading, but that can be disastrous in philosophical discussion. ‘Tho the one you cite seems to be one of the better approximations! ;-)

    (Note: prior comments in this particular conversation are #63 (Dartian), #75 (David Marjanovic), #83 (me) #87 (Dartian), #91 (David Marjanovic), #92 (Dartian))

  109. #109 Andreas Johansson
    November 14, 2009

    Really?

    I’m not chimpologist, but a brief google turns up a lot of weight ranges for male chimps that go up to 70 kg or so. ISTR the average being stated as 50 kg (I’ve also seen 70 but that’s presumably a confusion of maximum and average).

  110. #110 Nathan Myers
    November 14, 2009

    xenithrys has it right: The basic signature of arising sentience is a mass extinction, particularly of larger predators at first, then a holocaust. Unfortunately there are other causes of mass extinction, so it’s not (forgive me) a smoking gun.

  111. #111 Andrea Cau
    November 14, 2009

    Little meta-phylogenetic-nerd comment about the hypothetical evolution of a dinosauroid:
    Russell and Séguin (1982)’s Dinosauroid should not be a derived troodontid. Although Russell used _Troodon_ as its ancestor, when Dinosauroid (based on Russell and Séguin’s ’82 data, including a reconstruction of the skull) is included in a large scale phylogenetic analysis of theropods, it results sister-group of _Confuciusornis_: both share acutely angled rostrum in dorsal view, absence of subnarial process of nasal, robust postorbital forming most of caudal orbital margin, acute rostrodorsal corner of dentary, and complete absence of teeth.
    In conclusion of this absurd comment, the dinosauroid is probably descendant from basal avialians, and may be considered a neoflightless form.
    Is this the effect of taxon sampling artifact? More basal dinosauroids are needed… ;-)

  112. #112 Joe
    November 14, 2009

    Darren, Its difficult to ask this without appearing rude, (which isn’t the intent)but I’d love to see you do a post on an extrapolation from what you think might be the best dinosaur basis for intelligent evolution and what direction it might lead.

  113. #113 Chris M
    November 14, 2009

    Hey Joe, he’s done a bit on that in the nebulous, pre-ScienceBlogs past, especially

    http://darrennaish.blogspot.com/2006/08/bucorvids-post-cretaceous.html

    and

    http://darrennaish.blogspot.com/2006/11/dinosauroids-revisited.html

    Unfortunately, they don’t show up in the “previous articles” section, but they are linked in the articles he links to at the bottom. Good stuff! Spoiler alert, searching “ground hornbills” should also get you there.

  114. #114 Dustman
    November 14, 2009

    wow, there’s so much good conversation here.
    I think my own brain size got a little bit bigger since I started reading this thread. ;)
    jerzy,
    I’m serious in that I agree with the things you’ve been saying. I’m friends with the local “wild” birds but, no, I won’t be trying to explain blog comments to them.

    for what it’s worth, native english speakers often view not speaking english as a sign of low intelligence. no surprise bird intelligence has gone “unrecognized” for so long.
    ok, shutting up and lurking now.

  115. #115 Jim Thomerson
    November 14, 2009

    I think George Gaylord Simpson made a comment to the effect that a bird would consider it an insult to be called “manbrained”.

  116. #116 amphiox
    November 14, 2009

    Some disparate thoughts:

    A certain degree of historical contingency may impact a lineage’s capacity for evolving increased brain size. It could be, for example, that the mammalian neocortex is particularly amenable to rapid expansion over evolutionary time, while the archosaurian lineages might find it more difficult to expand brain sizes, from the point of view of neural development and circuitry.

    Conversely, among avians, the requirements of flight would assert selective pressure against increasing brain size, due to weight and balance constraints.

    On the other hand, anyone who has looked at the cytoarchitecture of the mammalian cortex will note the amount of “empty space” present between the individual neurons and glial cells. Is this arrangement necessary for optimal functioning of the neural circuits, or would it be possible, if appropriate selective pressures were applied, for a brain to be shrunk in size, but maintain the same number of neurons and the same complexity of circuitry, and thus the same sophistication of behavior, but becoming increasing cell density? Neurons is the brains of some of the more intelligent birds, for example, are in many places more tightly packed than in the brains of mammals.

    The superior respiratory efficiency of birds (and most likely their dinosaurian relatives) compared to mammals could allow birds to achieve equivalent intelligence with a smaller brain.

    It may be that for a comparatively less intelligent population facing selection pressure in favor of increased intelligence, the easiest way to evolve increased intelligence is to expand the size of the brain, but that after a certain level of intellect has evolved, with the accompanying complexity of circuitry, intelligence could be maintained or even increased despite new selective pressure in favor of smaller brains, but preferentially preserving the advanced circuitry and organization, even as the overall size of the brain shrank.

    Some more possibly long-lasting legacies of an intelligent species:

    Open pit mining, especially if they went into the bedrock. Could potentially endure for hundreds of millions of years, though perhaps may be difficult to distinguish from natural phenomena.

    Genetic engineering/domestication – relics of past genetic manipulation might be recognizable in the DNA of any descendant forms, again maybe for hundreds of millions of years. One would have to distinguish it from natural mechanisms of lateral gene transfer. Evidence of domestication might be evident in fossil specimens of the domestic species.

    I remain of the opinion that a intelligent, technologically capable theropod dinosaur species would not require any significant anatomical modification from their basic ancestral form other than the modifications of the skull necessary to accommodate an enlarged brain.

  117. #117 Joe
    November 15, 2009

    Thanks Chris for the links….. This time round I put a little intelligence into action, reread the post and I saw Darren had already linked to previous posts at the top of this post too!

  118. #118 Dartian
    November 16, 2009

    Jim (#97): Thanks for the link to Mayr’s paper.

    Allen (#108): Good point about Aristotle; his usage of telos would, of course, have been quite independent of any Christian influences (even though he could/would still have been using that term in a metaphysical sense). And yes, I realise that falling back on dictionary definitions is not an unproblematic approach. In my defence I can only say that this discussion is rather outside my academic comfort zone…

    Andreas:

    a brief google turns up a lot of weight ranges for male chimps that go up to 70 kg or so. ISTR the average being stated as 50 kg (I’ve also seen 70 but that’s presumably a confusion of maximum and average).

    Nowak’s Walker’s Mammals of the World (sixth edition, 1999) gives the following figures for chimp and human weights (the figures for humans, needless to say, are only ballpark figures):

    Pan troglodytes
    -males in the wild, 34-70 kg (up to 80 kg in captivity)
    -females in the wild, 26-50 kg (up to 68 kg in captivity)

    Pan paniscus
    -males, 37-61 kg
    -females, 27-38 kg

    Homo sapiens
    -male worldwide average, about 75 kg
    -female worldwide average, about 52 kg

  119. #119 Dartian
    November 16, 2009

    Dustman:

    for what it’s worth, native english speakers often view not speaking english as a sign of low intelligence.

    A thread like this, and nobody’s mentioned Monty Python yet (well, I kinda did myself in comment #9 but that doesn’t count)! Decades ago, they tested the intelligence of penguins and their capability to answer questions asked in the English language; they found that the scores of penguins were consistently equal to those of a non-English-speaking group of humans.

    Regarding possibly confounding environmental factors, it was also noted that:

    IQ tests were thought to contain an unfair cultural bias against the penguin. For example, it didn’t take into account the penguins’ extremely poor educational system. To devise a fairer system of test, a team of our researchers spent eighteen months in Antarctica living like penguins, and subsequently dying like penguins – only quicker – proving that the penguin is a clever little sod in his own environment.

  120. #120 Graham King
    November 16, 2009

    Does intelligence necessarily imply tool-using that would leave technological relics?
    Consider bower-birds. They select, collect, and PAINT to make mate-attracting ornamental nests. The complexity of those nests could develop enormously further and yet leave no fossil trace. Maybe impressing mates with one’s intelligence (problem-solving ability and innovation) can serve as a key driver of escalating intelligence in a species?
    Perhaps there was asophisticated race of dinosaurian poet/philosophers, their skills in abstraction and metaphor – and music? – honed through a drive to produce ever-more-beguiling love-songs?
    An appreciation of transience as an aspect of beauty (and need to maintain a competitive edge) might make them positively averse to leaving any material record of their intellectual labours. And not all species may feel a need to tinker with and despoil their environment for later generations to inherit and analyse.

    Aliens may be alien in mind and motive as well as physique. We humans readily embrace all kinds of parochialism as if our (present-day) preoccupations had to be a universal norm! when they are not, perhaps even at this moment, even a universal human norm.

    Oh look, who’s this appearing? It’s a naked luminiferous preter-ammonite from the 60th century.. communicating with me by telepathy.. he/she/it’s saying: “What? You hairless apes think you need a machine to travel through time?”

  121. #121 Dartian
    November 17, 2009

    Graham:

    Does intelligence necessarily imply tool-using that would leave technological relics? Consider bower-birds. They select, collect, and PAINT to make mate-attracting ornamental nests. The complexity of those nests could develop enormously further and yet leave no fossil trace.

    Hmm. On the other hand… Termites are not, as far as I know, particularly intelligent (even by insect standards). Yet they construct huge mounds that seem quite sophisticated – certainly far more complex than the bowerbirds’ bowers. And what’s more, termite mounds actually stand a chance of being preserved as fossils; fossil termite nests, some of which are several tens of millions of years old, are known.

    If, in some weird way, all termites had become extinct before modern humans evolved and we couldn’t study them as living organisms, how would we interpret fossil termite mounds? As the products of an “evolutionary experiment” involving sapient arthropods?

  122. #122 Dartian
    November 17, 2009

    Jerzy:

    a group of ravens ALWAYS outsmarts a group of wolves to steal prey

    Wonder how much outsmarting the ravens would dare to try if the wolves could fly too?

  123. #123 AD
    November 18, 2009

    [from Darren: delayed by spam-filter]

    @David, others- I did a little googling on Marsh’s Law, and came up with a few references and tentative conclusions. One, there does seem to be evidence for an overall increase in encephalization in mammalian assemblages over the Cenozoic, at least for Carnivora (Finerelli and Flynn 2009, Finerelli 2008) (www.pnas.org.libproxy.lib.unc.edu/content/106/23/9345.full.pdf; paleobiol.geoscienceworld.org/cgi/reprint/34/1/35)

    BUT, sociality is not sufficient or necessary to explain increasing encephalization within Carnivora.
    An “early modern” :-) paper, Jerison 1970, (www.sciencemag.org/cgi/content/abstract/170/3963/1224) found evidence for increasing encephalization of mammalian assemblages in general over the Cenozoic, although this has been disputed by Radinsky (1978) (www.jstor.org/pss/2460160). Franzosa (2004) counters Jerison (1970) and the earlier “Marsh’s Law” authors on the supposed “reptilian” nature of the theropod brain, rather finding a gradual evolution of the avian-style brain throughout the evolution of theropods (repositories1.lib.utexas.edu/bitstream/handle/2152/1145/franzosajw504611.pdf). This conclusion is supported by Kundrat (2007), who found the putatively secondarily flightless Conchoraptor to be encephalized within the range of modern avians (while Archaeopteryx is on the low side) and to have more resemblance to derived avian brains than to archaic avialans such as Archaeopteryx. Overall, however, the main similarities stressed in these papers between non-avian and avian dinos is that they have similarly advanced sight and coordination-related brain centers, a conclusion also reached for a comparison between avians and pterosaurs (a paper many are probably familiar with, and which touches on phylogenetic inertia) (Witmer et al. 2003) (www.nature.com/nature/journal/v425/n6961/abs/nature02048.html).

    So, we have multiple maniraptorans falling within the EQ of modern birds, but nothing to suggest the evolution of even Carnivoran level intelligence- although if they had persisted for another 30 million years, perhaps? But even on the topic, the highest levels of intelligence, which begin to approach hominid intelligence are not Carnivorans (exception maybe pinnipeds) all found within lineages that directly depend on angiosperm fruits (in the broad sense of the word), with cetaceans being the exception (but hey, the ocean is a different environment with different constraints- e.g., largest animal ever known is marine).

    It appears that sociality is not sufficient (or even necessary) for the development of advanced encephalization, at least in Carnivora, so the search for the necessary qualities/circumstances for the evolution of advanced intelligence continues. One might still say sociality is a required component for the evolution of the most advanced levels of intelligence- so perhaps that depends on the type of sociality, or sociality contingent on other factors; and also, it depends how “intelligent” or encephalized you are talking about.

  124. #124 AD
    November 18, 2009

    A belated apology/explanation to Viergacht for my sarcastic comment, which was undeserved, but it annoys me when people say things like “we have no idea what could have happened”, as if evolution was some string of non sequitors. It’s also not very scientific, to say “oh, we’ll never know” while ignoring the available predictive hypotheses or evidence, or the possibility of evidence that remains to be gathered or hypotheses developed.

  125. #125 Nathan Myers
    November 18, 2009

    All nuanced considerations aside, I blame Scientific American for taking the opportunity to reproduce, once again, that absurd graphic with other than derisory caption and title. What’s next, drawings of the elaborate Martian canals, plied by exquisitely alien-looking barges? A lone plesiosaur’s neck arching gracefully above the Loch’s surface? Stephen Hawking standing after sucking down a homeopathic remedy? “Cannot be ruled out“, the headlines will read.

  126. #126 Dartian
    November 20, 2009

    AD:

    the highest levels of intelligence, which begin to approach hominid intelligence are not Carnivorans (exception maybe pinnipeds) all found within lineages that directly depend on angiosperm fruits (in the broad sense of the word), with cetaceans being the exception

    Elephants are also an exception to that. Proboscideans are almost certainly primitively browsers, and the modern species eat mainly leaves and grass; fruits are a relatively minor component of their diet. The diet-intelligence relationship, if there even is one, clearly is very complex.

  127. #127 Jerzy
    November 20, 2009

    @Dartian
    Well, ravens are equally successful stealing food from eagles.

    BTW – recent Handbook of Mammals of The World has interesting data from lions, hyenas and wolves. Taken together they suggest that driving force in predator sociality may be not hunting cooperation, but cooperation in defence of carcasses.

    @Nathan Myers
    Martian canals should not lose place to dinosauroid! Let’s start our own meme. What about an article that climate change will force gigantic irrigation projects? And some colorful illustration of supposed Martian canals? There is at least one talented artist on this blog!

  128. #128 Ilja Nieuwland
    November 28, 2009

    Our own position necessarily makes us rather intelligence-centric when determining what we see as anatomical advantages, and our teleogocial mental setup makes it difficult to look upon intelligence as the eventual outcome of any evolutionary development. Yet ‘extreme intelligence’ is quite a rare phenomenon, as are situations in which such intelligence provides a selective advantage. Usually, gains in other areas are much more advantageous, and although sometimes these require a greater degree of processing power (as with social and locomotory skills) it is not a given.

  129. #129 Devonian
    December 3, 2009

    “Open pit mining, especially if they went into the bedrock. Could potentially endure for hundreds of millions of years, though perhaps may be difficult to distinguish from natural phenomena.”
    Interestingly, I’ve read at least one anecdotal account of a prehistoric mine being discovered (in a book on the paranormal, of all things). However, the source is… less than reliable…

  130. #130 Spencer
    December 27, 2009

    If I had to put money on a SPECIFIC alien body plan and evolutionary history, I’d go with the humanoid, simply because its always better going with a known than an unknown. That being said, it’s also easy to believe an alien is likely to be a non-humanoid, but that wouldn’t be a SPECIFIC proposal, any of which is more likely to be wrong. It’s still fun and productive to reason through the how and why of a hominid form and possible convergences and divergences in body-form and lineage.
    A great hominid argument would be that the human lineage has always inhabited a demanding peak niche and this niche naturally transforms into the other. From gibbonoid, to primate, to peak arborial predatory warmblooded generalist, to clawed tetrapod, all the way to a fish (i.e. a muscular tube with an ouchy clamp on the end)

  131. #131 Charles Benjamin
    January 4, 2010

    Convergent evolution is the first thing that struck me as I read this. The best examples are probably the similarity of body shape in fish, ictheosaurs, and dolphins. Four very different genus of creatures separated by millions of years of evolution, adapting to the same watery environment. Human beings have a semi-aquatic biological characteristic which I imagine is related to the length of time we spend in the womb: slightly webbed hands which help stabilize us within the amniotic fluid of the womb.
    In terms of another genus of creature evolving into a bipedal form with long arms and hands that could grasp objects, the dinosaurs, in the form of struthiomimus and the raptors, had already achieved this. However, they had the avian form of bipedality, not the human form. But it confers the same advantages. There is a height advantage in being able to see danger coming from farther distances. Arms no longer needed for movement, can reach forward and grab prey whilst running at the same time, or indeed carry prey whilst moving, to a safer location for consumption for example. This could later be adapted to holding tools whilst moving (the primate grasp was initially used for holding onto branches, and only later adapted to using tools). There’s no reason to imagine that the raptors wouldn’t have evolved into intelligent bipedal (if not strictly humanoid) beings. Perhaps some of them had evolved into beings with comparable levels of technology to us, or better, and fled the Earth before the impact that wiped out most life 65 million years ago. Uh oh, really straying into the realms of science fiction now :)

  132. #132 David Marjanović
    January 5, 2010

    slightly webbed hands which help stabilize us within the amniotic fluid of the womb

    Where did you take this remarkable assertion from?!?

    There is a height advantage

    Well, no, because the dinosaurian form of bipedality keeps the body horizontal.

    Perhaps some of them had evolved into beings with comparable levels of technology to us, or better, and fled the Earth before the impact that wiped out most life 65 million years ago.

    That should have left evidence of the kinds mentioned above.

  133. #133 AD
    January 20, 2010

    Hey back to the whole intelligence thing:
    @Dartian, others: a 2001 PoRS-B (??) paper suggesting the common link between the large brains of hominids, odontocetes, and proboscideans is an emphasis on “extreme mutual dependence based on external threats from predators or conspecific groups”, so back to the whole social intelligence thing. So perhaps the diet(specifically fruits, nuts) is important to high encephalization/intelligence inasmuch as it foments a social structure like these three groups have. Also, given the earlier-linked-to PNAS paper that suggested that a lack of correlation between high sociality and encephalization among carnivorans, perhaps it is necessary to split hairs about what KINDS of social structures are required to reach peaks of encephalization, and perhaps diet plays a role in encouraging the ‘right’ social structures to arise.
    Anyway I think the main point of interest here is the suggestion that sociality plays a key role in the evolution of hominid, African gray, odontocete, and proboscidean-level intelligence.

    links:
    PoRS-B: http://bit.ly/7x9Age
    PNAS Carnivora paper: http://bit.ly/6WUWOU

  134. #134 Dartian
    January 21, 2010

    AD:

    a 2001 PoRS-B (??) paper

    Actually, the paper you link to is from 2007. As for the abbreviation of Philosophical Transactions of the Royal Society B*, the journal itself uses Phil. Trans. R. Soc. B.

    * Not to be confused with its sister journal, Proceedings of the Royal Society B (a.k.a. Proc. R. Soc. B.).

    Anyway, thanks for the reference, I wasn’t aware of that paper. Will read.

    suggestion that sociality plays a key role in the evolution of hominid, African gray, odontocete, and proboscidean-level intelligence

    Even at the risk of slightly moving the goalposts, I can’t help but to note that sociality is probably not the explanation for why cephalopods (AFAWK the only non-vertebrate clade that evolved ‘high’ intelligence) became so smart…

  135. #135 AD
    January 22, 2010

    Whoops, that was an utter fail on the reference- year, journal name, abbreviation, etc. Although I am aware of the proper abbreviations, I was just trying to compact it.

    Yeah, I guess there are several levels of intelligence there, and I would say that including cephalopods moves the goalposts, since the group I mean when talking about near-hominid-level intelligence includes odontocetes, chimps, and proboscideans (perhaps also crows and african grays) excludes carnivorans (which as noted do not follow a sociality-encephalization correlation) and so that group would exclude cephalopods as well. On that topic, I guess it is debated how intelligent cephalopods are; you hear “smart as dogs” but I have also heard that they are really just good at solving particular problem types, like opening things.

    I think however we are talking about several types of intelligence in these comments however: some are asking about encephalization quotients in the dinosaurian era and how they compare to modern birds and mammals; some are talking about dinosaurian vs modern bird and mammal intelligence, meaning African grays and chimps, which really are their own superstar class amongst birds and mammals; and then some are talking about the notion of humanoid-level intelligence in the Mezazoic, what form it would take and (oddly, in my view) whether it could have existed without leaving evidence. In my most recent post I am talking about what conditions have allowed evolution of superstar-level intelligence, not just relatively high intelligence eg of carnivorans. So as far as dinosaurs go, you’re right they probably had to at least get to carnivoran level before we can start talking about superstar level. I am not talking about whether eg angiosperms were necessary to get dinosaurs to carnivoran-level, but rather whether they might have helped foment something closer to crow, dolphin or chimp level. But at this point I guess we don’t know enough about what the proximate factors are in evolving high-intelligence to begin to rigorously look at what might have “set the stage” for these proximate factors/requirements to be able to play out.

  136. #136 AD
    January 23, 2010

    Speaking of carnivoran encephalization, I think it would be interesting to look at encephalization of pinnipeds in relation to sociality, as did the PNAS paper for canines.

  137. #137 AD
    January 25, 2010

    Probably talking to myself here, but did anyone catch the recent Scientific American article on evolution of hairlessness in hominids? It presents a convincing argument of how hairlessness was a prerequisite to evolving other human characteristics, like a striding bipedality and large brains that are sensitive to overheating, among other factors. You begin to wonder how many degrees of freedom there really are in evolving an organism with hominid-level intelligence, at least when starting from a terrestrial mammal bauplan.

  138. #138 Eikin Kloster
    February 3, 2010

    I think we’d have to focus on the circumstances that do privilege a growing intelligence up to technological level. One of the turning points of intelligence VS physical power that I see is being able to use spears. Spears are the first weapon to give clear advantage to humans over other predators. And the movement we make when throwing spears look suspiciously similar to the one apes such as gibbons do when moving on tree branches. So perhaps being able to swing on branches is a constraint on developing a spear based fighting style. Not so hard to imagine a non-avian theoropod living an arboreal life and developing a primate-like body plan.

    I do think the dinossaurid is an exageration, too within the average human proportions. It could be more like an Eva from Evangelion, with subtle but striking differences from the human canon.

  139. #139 Eikin Kloster
    February 4, 2010

    All other lines of high intelligence that we know might have perched on one of those inescapable localized peaks on Dawkin’s Mount Improbable. Even humans might have reached a localized peak. Intelligence only grows when more intelligence is advantageous for reproduction. That is clearly not the case with us presently, since the brightest people, on average, reproduce the least.

    It is interesting to consider that in a way technological level intelligence is a rarity even among humans. We all know how to use some level of technology, but how many of us can actually develop technology? Less than 1% of us probably. Maybe closer to 0.1%. How many of us can, for instance, really understand the algorithms for solving Rubik’s cube? I know I can’t. I have to memorize the algorithms, and when I forget them, I have to memorize them again. I can’t find them on my own. I can only wonder the abyss that exists between my type of intelligence and the type of intelligence of a true Rubik’s cube solver.

  140. #140 thesnizzle
    March 7, 2010

    ALL HAIL DAWKINS AND HIS GIANT MAGICAL A! I can’t wait until the government mandated atheist worship centers are put into place, so we can all commune in the glory of ATHEISM!

  141. #141 HunterJE
    December 31, 2010

    As cool as convergent evolution is, this idea that any two species evolving into a similar niche, regardless of background, will invariably end up with a similar body plan just doesn’t line up with facts; if it did, kangaroos would look a lot more like antelope than they do.

  142. #142 metridia
    February 1, 2011

    Some more cool intelligent-maniropteran visuals…if they haven’t already been suggested

    http://www.robotblood.com/2008_09_01_archive.html

  143. #143 Bryce
    May 3, 2011

    The picture of the Dinonychus(I am sure I am spelling that wrong but whatever)holding a spear is hilarious. He or she has got big claws and sharp teeth and yet is holding a silly piece of wood. From my very elementary understanding of our elementary understanding of human evolution a changing climate forced a once tree based creature to survive on a savanna, we were and still are the nerd species who needed to fashion a sharpened stick to survive, something we only barely did. Dinonychuses were plenty smart hunting in packs takes a lot of thought and strategy, they used what they had well and what they had were built in weapons. Using what you got well is sort of a common sense definition of smart. Our evolution was an accident although even that word is wrong because it has moral judgement, if a species is surviving it is being “smart”. I suppose there was a potential for some kind of evolution similar to ours to take place during the catastrophe that killed the dinosaurs. It sounds like that evolution was birds, also our most ancient mammal ancestors of course. To say if only Dinosaurs had a bit more time is also silly. They had plenty of time and did a very impressive amount of evolving. The size and sophistication of those beasts of the Cretaceous Period the ones we tend to love the most was probably their undoing. For slightly different reasons we have an even bigger appetite than those massive Dinosaurs which should worry us. its animals like cockroaches and ants and maybe rats who are best prepared for another extinction event to take place.

  144. #144 David Marjanović
    May 4, 2011

    From my very elementary understanding of our elementary understanding of human evolution a changing climate forced a once tree based creature to survive on a savanna, we were and still are the nerd species who needed to fashion a sharpened stick to survive

    Almost. Near the top left corner of this page, there’s a search engine. Enter “spear” and click on the first result.

    A savanna is not necessary for inventing the spear.

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