Quiz time! What's wrong with this paragraph?
Sometimes life takes a creative leap that's almost miraculous. Nobody knows how this happens, and it can never be predicted. You'd never know, looking at a reptile's round, hard, shiny scales, that they could genetically morph into feathers. Paleontologists know that they did, however, and finding the very first dinosaur that sprouted feathers is one of the great discoveries waiting to happen.
I think we all know what's a bit off here: whoever wrote this seems to have completely missed out on what has become almost a commonplace observation: lots of dinosaurs were feathered, and we've got plenty of fossils with feather impressions. Recently, I mentioned the spectacularly weird Epidexipteryx, and if you want more, look at this article about Juravenator starki. Juravenator was not feathered — and that's what made it unusual, that it was a lineage nested among many other species that were known to be feathered. Look at all the feathered coelurosaurs in this chart!
Next question: who made this dopey comment? A hint: he's known for saying dopey things, and has pontificated on evolution before, with a similar degree of ignorance.
Give up?
It's Deepak Chopra. He's trying to make a metaphor, that the Obama administration will be an evolutionary breakthrough, but all he manages to do is sound like an uninformed dweeb.
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*headdesk* The stoopid, it hurts. How can I eat dinner after that tripe?
Oh yes, I used to teach. Carry on.
So it's just business as usual for him then? Mr "science stole the word quantum from me"
Like Julia Sweeny said (regarding Chopra and his claims about quantum mechanics) "Deepak Chopra is full of SHIT!"
Just as a side note, Deepak Chopra is referenced in the New Futurama Film, "Bender's Game".
That was the moment of the film.
What a coincidence. I'm currently in the middle of a debate with a Deepak follower about (Deepak and Quantum Physics).
PZ, can you invent some strong Deepak-Antidote? We can inject that into all the people poisened by this man. I used to be a victim of his crap. And not to metion Maharishi Mahesha Yogi too. Read the debate here:
http://hinduatheist.blogspot.com/2008/11/hijacking-quantum-physics-for-…
Hmmm... Now I know where the really bad, sciency sounding dialog for the character Mohindar Suresh in Heroes comes from.
Read that again:
So do we know already which was the very first dinosaur that sprouted feathers? If we don't, then Chopra's statement is valid.
Oh, I almost forgot to invite everyone to come & bust the Chopra & Quantum Physics bubble? There is abuse hurled at "Dawkinsian jokers stuck in Newtonian age". Are you one of them?
http://hinduatheist.blogspot.com/2008/11/hijacking-quantum-physics-for-…
Follow the link and read the rest. No it is not valid.
Also, there should be a comma after the first word in the paragraph.
@ #8 -
Well, thats a loaded question. The first dinosaur fossil showing evidence of feathers was, if I recall, Sinosauropteryx prima found ~1994. As for the earliest example of a feather... Albertosaurus is probably the best bet there - though feathers are inferred from other features rather than directly observed.
Of course that's just the oldest one we know of - there could well be earlier specimens that we have yet to discover. That's the problem with Chopra's statment - there is no first feathered dinosaur, only the earliest example we can find. There may well be older examples out there. In fact there is even evidence for feathers in animals predating the dinosaurs!
I have been calling this slime Deepcrap Chopper since I first heard of his moronic puking, and there is no need to change his moniker or my opinion. A moron who I lump with Dinesh DiCrappa. Morons in the flesh and brains.
Deep [6 p]ak Choppra's statement, in context, can have the meaning PZ has ascribed to it- that Dinosaurs with feathers have not yet been found. Choppra is his usual vague and nebulous self. I never knew evolution took 'creative' leaps, I thought unique combinations of characters allowed colonization of new adaptive niches.
Is quote mining one of your hobbies cm :P?
Reading the rest, it looks like he misunderstood Archaeoraptor's "missing link" hype. Still, I agree with cm that what he's anticipating is the fossil of the first feathered dinosaur (which is what he believes Archaeoraptor was supposed to be), not the first fossil of a feathered dinosaur to be found.
Compared with Chopra's usual confusions, that's not too bad.
"it's the next stage in human evolution!"
I have a real problem with this statement, how do feathers eventuate into flight?
No, see, you guys don't get it. He doesn't mean scientific evolution, he means Pokemon evolution. This country is going to sprout feathers and evolve into Obamanation as soon as we reach level 15.
There are even more than that PZ. I recently compiled a list on my blog:
http://archosaurmusings.wordpress.com/2008/10/25/the-feathered-dinosaur…
Even if you exclude Archeopteryx, there are at least 17 species.
The whole idea of a metaphor is to make things simpler for your audience to understand. However, Deepak Chopra's metaphors seem to use advanced scientific concepts (e.g, quantum mechanics, evolutionary biology,etc.) which most laymen have little knowledge of. It seems like he is just using these scientific concepts to intimidate his audience. He is also implying that his ideas have as much weight as the scientific theories he cites, which they obviously don't.
I had a religion teacher in high school who did the same thing. She cited Newton's 3rd law, every action has an equal and opposite reaction, to try and get the point across if you do something really bad to someone their reaction will also really bad. This is probably true in most cases, but most the students in the class hadn't taken physics yet so why bring it up? I also remember hearing her abuse relativity with some sort of "it's all relative" argument.
Is quote mining one of your hobbies cm :P?
Not that I was aware of, but I hope so: I need hobbies.
Deepak was spewing crap about the purpose of the universe on seesmic today. He's really, really good at spewing crap.
Chopra is a master at selling woo.
Anyone who claims to have a line on the true meaning of life and spirtuality and then sells that "truth" for thousands of dollars a pop at private retreats in La Jolla, California to rich anorexic women with perfectly streaked hair, too many plastic surgeries and driving Escalades and Navigators is pawning some seriously expensive snake oil.
In primary school, I had a teacher who tried explaining that law. Her interpretation? If you push against a rock, no matter how heavy the rock is you will still move it. That didn't make sense to me then, but I lacked the knowledge to explain why. Then when I got to high school and did physics in year 10, I became armed with the knowledge that could rationalise why I knew she was wrong.
#16
I just hunted down my "favorite" Mohinder voice over bit:
When evolution selects its agents, it does so at a cost. It makes demands in exchange
for singularity. And you may be asked to do something against your very nature.
Can we count the number of things wrong with that statement? And that's in only two sentences. My roommates never understood why I had to leave the living room until the voice over was done... Though to be fair, this might simply be an example of consistent characterization. The man was dumb enough to go roadtripping with a serial killer.
PZ, Do you think it is worth your time to debate this guy? But can you seriously expose his mis-understandings on biology and evolution? Dawkins interviewed him for his program. It is pity that many people fall victim to his herbal therapies, astrology predictions and quantum mumbo-jumbo. I bet he gets paid to be on CNN and other channels. Sometimes, I even wonder if he himself is aware that he is bullshiting.
"Juravenator was not feathered -- and that's what made it unusual, that it was a lineage nested among many other species that were known to be feathered."
Um, the idea that, "Juravenator was not feathered" is speculation at best. It is actually rather piss poor speculation as well..
ah, the less we think we know about something the more mystical pseudobullshit (yes... that's right... not even real bullshit) we can interject. let's not forget. this is also how politicians work. insert nationalistic for mystical.
Turn the page. If it doesn't sound like he's not talking about Lamarckian evolution on it I will eat my hat*.
*Jk
Chopra is the Oprah of New Age obscurantist doo-doo. Next he'll be touring with that other quackatronic David Hawkins.
P.Z., why u hurt head?
Almost sounded like an excerpt from a new X-men trailer
Too bad nature isn't so cooperative and doesn't divide everything into neatly organized categories. For there to be a "first" feathered dinosaur, there needs to be widespread agreement on when a non-feather becomes a feather, so even if the fossil record ends up being complete (ha!), it's going to be a long time before the fights over which is the "first" feathered animal dies down ...
Quiz time! What's wrong with this paragraph?
Well, for one thing, the sloppy language confounds evolution with development. Individuals don't evolve, populations do.
@20 aye. well put.
I would agree it's invalid, but not for the reason you say. On the one hand, if you were able to classify all indivudual animals as either "feathered" or "not feathered", there would have to be a first (even if some feathered animals were not decended from the first).
On the other hand, there were obviously borderline animals, that had some sort of feathery-scaly thing going on. So the statement was similarly dumb to someone saying "wow you've grown tall since I saw you 5 years ago. I would have liked to have seen the moment it happened"
Off-topic, but PZ, I was hoping you'd tell me if that was you I saw in the Lincoln HyVee buying beer the other weekend.
Since you were in Kearney, and all. You didn't mention anything about being in Lincoln (and, jealousy that lame Kearney enjoys a PZ talk but UNL gets no love?) but I saw someone I thought was you.
If it was, I was the guy in the green hat checking your blog on his iPhone trying to see if you had said anything about being in Lincoln. :D
I don't know about you guys, but one of the saddest days of my life was when I found out just how much the makers of Jurassic Park got the velociraptor wrong. Imagine my appalled horror when I discovered they were only a few feet tall and had feathers. It's like the kid in the film said all along. Nothing but a big turkey.
Frodo, but doesnt the discovery of the Utah Raptor make it all better?
PULL OUT THE GIANT FONTS.
It's Origin of Species Day. Hooray!
Published on November 24, 1859!
http://en.wikipedia.org/wiki/On_the_Origin_of_Species
got an error you guys missed:
that's because they didn't. feathers are fundamentally unrelated to reptilian scales, and evolved from hair-like structures.
further, it's actually sort of backwards: scales evolved from feathers. genetic tests on chicken embryos have shown that it's the addition of a single gene that is responsible for transforming a bird's foot-feathers into scutes, the broad flat scales on the top of the bird's feet. this backs up the fossil evidence, with foot feathers on microraptor and some evidence that archaeopteryx's ancestors probably had them too. on modern birds, these scales have a completely different chemical composition than the round, reptilian scales on the bottoms of their feet.
"scales evolved from feathers."
Again,, wild speculation that the scutes/scutellae and such evolved from feathers. Certain aspects of development, and how we can alter develop, has made some people speculate that scutes evolved from feathers.
This is still wild speculation at this point as their reasoning assumes too much...
Earlier today I found a site called "Big Think." Videos explaining stuff. Well produced videos. I thought it was the perfect site for someone like a P.Z. Myers to hang out. They have Lisa Randall. There were a couple of good researchers from Pfizer. Wow, wouldn't Ken Miller be good here, Niles Eldredge, Andy Ellington . . . you sorta get the picture. (You can see my post here:
http://timpanogos.wordpress.com/2008/11/24/the-value-of-science/ )
Then I did a search for "evolution." The first two vids are Chopra making a case for intelligent design.
Big Stink. That would be a better name until they clean it up. And then you confirm it here.
Chopra's extending his stupid from biology to politics. Wonderful.
Not this frigging guy again! I went to my mother's book club meeting this weekend, where we discussed Randy Pausch's 'The Last Lecture'. It was interesting, in an appalling sorta way: I thought the book and his lecture was fantastic and incredibly inspiring in a very real way. The other 5 women, not so much. They thought it was OK, but not a terribly exciting story, and proceeded to settle on 'getting back on track' by reading Deepak's '7 spiritual laws of success' or some crap like that for their next book. I politely declined their invitation to return for the next meeting. I find it so sad when people, including my mother, get so sucked into this crap... such a waster of time!
Summary of his bigthink evolution video:
Evolution includes (in addition to random mutations and natural selection) quantum leaps in creativity. Hence we should include a creative element since consciousness is all pervasive and transcends space and time.
**Arrrgghhhh**
I saw it sometime ago and wondered why no body talks about these things..
I just thought I'd mention that if you anagram 'Deepak Chopra', you get 'He poked a crap.'
Thank yew.
I have similar issues on my blog forthesakeofscience with a creationist named Jack.
lago, it's pretty simple. you remove one gene, and the structures that normally turn into scutes instead turn into feathers.
since ontogeny has something to do with phylogeny, this means that birds first grew feathers on their feet, and that scutes were then a secondary adaptation of those feathers. and the fossil record backs this idea up.
it's not "wild speculation." there are two different lines of evidence behind it.
"lago, it's pretty simple. you remove one gene, and the structures that normally turn into scutes instead turn into feathers."
I get the "idea" but the idea is an oversimplification of what goes on both in development, and in the evolution of novel morphology. Morphological changes happen by both the activation of novel genes, and the differential expression of genes previously present.
In other words, the gene expression that was nullified could just as easily been utilized as suppressors that inhibit the expression of novel morphology not suppressed in other regions during development, that are actually novel. Once the stop gait was removed, the novelty spread to regions were such novelty had been earlier protected from.
To simply pick the pathway the authors did, was extremely speculative, as they are deciding with certainty what is not illuminated between numerous options.
Or, indeed, "poke head crap". Not sure which one works best ;-)
@arachnophilia
So originally birds had feathered feet, no biggy, lots of extant birds do too. So how then do you get unfeathered feet subsequently? If a mutation inhibits feathers then you get an oven ready bird without feathers. If you want to do featherless feet you either have to coopt some genes that are on only in ankles/feet (difficult) or you aquire a new gene (New Scientist has a nice article on all the latest known mechanisms to get new genes without lateral transfer) and bolt that on top.
None of this argues that scutes evolved from feathers, the only possible thing you can conclude is that if you inhibit feather formation then scutes are the default. Like if you remove SRY you get females regardless of the present of the rest of the Y chromosome.
The disappearance of a feature does not necessarily mean the removal of the relevant genes, usually because most genes in complex organisms do more than one thing. Vis that you can make Hen's teeth by recombination with mouse epithelium. Chickens didn't lose the ability to make teeth, they just lost the signal to do so. Ditto scutes. It is far more parsimonius than that scutes evolved from feathers.
I can't believe Microsoft chose him for one of their "I am a PC" ads.
Actually... given the quality of Microsoft's advertising, I can.
CHOPROLITE - (cho'-pro-lite) noun
A piece of the fossilized fecal matter that passes for thought in the strata of Deepak's infinitesimal cerebral cortex.
I'm Sparticus- sorry, it seems so natural a response
nice milo. And what substance would you call that which sits inside Groppi's cranial cavity?
"So originally birds had feathered feet, no biggy, lots of extant birds do too. So how then do you get unfeathered feet subsequently?"
Ok, scutes evolved before birds did so why would the oldest known bird need to have feathered feet?
"Like if you remove SRY you get females regardless of the present of the rest of the Y chromosome."
Male and female are not evolutionary descendants from one another in tetrapods. You are dealing with a hermaphroditic past where one aspect in stimulated while repressing another that is also present. To paraphrase this into our discussion, scutes could very well be basal, and modifications of scutes could have evolved, with differential expression brining about different outcomes by both novel gene expression, as well as suppression, and induction methods. This does not show feathers and scutes, or male-female, to be basal to one another in this discussion...
"Chickens didn't lose the ability to make teeth, they just lost the signal to do so. "
No one ever said they did lose an ability. The fact is, genes can be lost, or modified in how they are expressed, and this can happen differently in different regions of the body by numerous methods, including novel gene suppression.
"It is far more parsimonius than that scutes evolved from feathers."
So, what did you exactly say that showed this?
But PZ, Deepak is rich and you're not. Proof positive that there is no god. Deepak is a master of technobabble and most of his readers and fans are too clueless to notice.
I'm fairly certain that Oprah is the Oprah of New Age obscurantist doo-doo. To my knowledge she has popularised Chopra's nonsense, The Secret and Jenny McCarthy's would-be-indigo-parent, antivax bollocks.
...feathers also evolved before birds. the first dinosaur that we call a bird, archaeopteryx lithographica, had quite well developed flight feathers. they didn't just pop into existence.
feathers also probably evolved before flight. a dinosaur might have needed them for warmth, or display. and recent wind-tunnel testing suggests that microraptor needed its foot-feathers to generate enough lift to not go crashing to the ground everytime it jumped off a tree.
i'm not sure how you can arrive at that idea. that's completely backwards. the study shows that feathers are the default condition, because it takes a mutation to supress them. scutes are a secondary characteristic. not something that was there, went away, and came back again. the gene makes the feathers become the scutes, not makes the feathers go away.
#27
Agreed. If we had a fossil of a bird with integument preserved only on the legs covered with scales, we wouldn't conclude that the bird was completely featherless. Only that the preserved parts were.
The first dinosaur fossil showing evidence of feathers was, if I recall, Sinosauropteryx prima found ~1994. As for the earliest example of a feather... Albertosaurus is probably the best bet there - though feathers are inferred from other features rather than directly observed.
Okay, this is a bit OT and rather nitpicky, but I'd like to guard against creotard quote mining. Why are you saying that the best, earliest example of dinosaur feathers is Albertosaurus?
A. I must have missed the paper where they found feathered Albertosaurus fossils (phylogenetic inference doesn't equal data). Seriously, if I did somehow miss such an article, please point me to a citation.
B. Albertosaurus (ignoring any Gorgosaurus issue) comes from rocks that date to the upper Campanian or (perhaps) lower Maastrichtian (uppermost Cretaceous), so we're talking an age range in the neighborhood of 74-70Ma.
C. Sinosauropteryx or no Sinosauropteryx, Archaeopteryx is both a theropod dinosaur and one which possessed feathers. It comes from the Upper Jurassic. There's some disagreement about the specific system, but we're taking rocks on the order of 155-150Ma. That's about twice as old as Albertosaurus. Rather earlier.
#58
Has anyone tested crocodilian scutes to see if they can be coaxed to turn into something feather-like? If this happened, we'd have a strong case that scutes evolved from feathers. It would also lend credence to the hypothesis that protofeathers evolved in the common archosaurian ancestor of dinosaurs, pterosaurs and crocodiles, and were subsequently lost in some lineages.
"...feathers also evolved before birds. the first dinosaur that we call a bird, Archaeopteryx lithographica, had quite well developed flight feathers. they didn't just pop into existence."
I did not say they just popped into existence. It was you that said: "So originally birds had feathered feet, no biggy, lots of extant birds do too." not I. I was only responding to the weird non-sequitur you had come up with stating that the first birds had feathered feet due to your logic. They may have had feathers on their ankles and feet, or not. I do not get how it was relevant to the conversation, or how your logic even pointed to the suggestion, let alone mine.
"feathers also probably evolved before flight. a dinosaur might have needed them for warmth, or display. and recent wind-tunnel testing suggests that microraptor needed its foot-feathers to generate enough lift to not go crashing to the ground everytime it jumped off a tree."
First, I really do not need a lesson in extreme basics. Next, nothing you have said indicates what evolved from what."Needing" does not indicate a source for feathers, or a selective force for deriving scutes from a feather precursor. Also, more relavant to the conversation, Scutes are found in crocs, dinosaurs and birds, and the dino-croc split is almost certainly way before birds showed up. Are you implying crocs, or their ancestors, used to have feathered hands and feet? If you are to be consistent, I think you must.
"i'm not sure how you can arrive at that idea. that's completely backwards. the study shows that feathers are the default condition, because it takes a mutation to supress them. scutes are a secondary characteristic. not something that was there, went away, and came back again. the gene makes the feathers become the scutes, not makes the feathers go away"
Genes are expressed to make morphology by both the expression of genes in a region, as well as the suppression of genes in a region. If genes were allowed to mutate in a separate region due to a lack of certain genes being suppressed there, when they were suppressed in the past, (hence allowing the selection for other genes to effect the regional outcome) then a novel structure could have evolved in one region, from a previous trait, and still remain what it was in other regions of the body unchanged. If those older suppression genes are inhibited, the novel structures could be then expressed in the previously unexpressed region (as in the wall has come down). To some, this might appear as default, when in reality there is no way to know that by this information* alone. Stating so is simply an overly simplified understanding of development, and not good science to assume with so little in the way of clarification.
*as in the repressing of a gene leaving a totally different trait.
"Has anyone tested crocodilian scutes to see if they can be coaxed to turn into something feather-like?"
No, no one has that I have heard of, but this is not a damnation of the possibility that feathers were first. In birds, both scutes and feathers have been present for millions of years, and are still expressed, but feathers, if they were ever were in the crocodilian ancestral lineages (as in crocs, and their pre-croc ancestors), they have obviously been lost for quite some time, and the genes that might have been responsible could have just mutated too much to now express feathers as a "default."
The paper does not show that the new gene (note the difference from a simple mutation) is necessary and sufficient for scute formation. It only shows that if you inhibit feathers you get scutes. This of itself does not allow you to conclude that they are derived secondarily from feathers.
Also I was not making an evolutionary point with my examples. I was pointing out that the molecular basis of uncovering default states is well known in other systems. You will need far more than this to persuade me that scutes are a more derived characteristic than feathers. Especially in an animal with reptilian ancestors.
When I think of dinosaurs, I STILL have a problem imagining them with feathers.
The toys and cool things of my youth are just still that strong, you know?
Knowing that velociraptors had feathers and were roughly the size of a turkey (but with a much larger tail), kinda ruined the whole Jurassic Park experience for me.
It just makes the filmmakers look rather ridiculous.
..though not as ridiculous as mister Chopra.
Right... So.. Scales, sweat glands, feathers, mammary cells, and hair cells come from the same basic tissues, right? But.. What the hell is Deepak Chopra on in the rest of it? I mean... presumably it was fluffy scales -> downy fluff -> fluff onna stick -> featherrs, right? It's not that weird, and there's no clearcut point at which the scale becomes a feather - it's a continuum.
Does that ad really say "Give seed."?
I did that once for some extra money... It was easier than giving blood.
First of all, by "the very first feathered dinosaur", Chopra really does mean the first to be found, not the first one that ever existed. Evidence? He cites the 1998 hoax as evidence that no feathered nonavian dinosaur has been discovered yet.
(And in doing so, he ignores the fact that the hindlimbs and tail of that hoax, which belong to Microraptor, have feathers preserved.)
What?
Not at all, that's how. "Historical inevitability" is Marxism, not the theory of evolution.
It was not feathered on part of the tail. For the rest of the body we don't know.
Which in turn are just elongate scales that grew off the body surface.
Now, mammalian hairs are probably something different...
I just spent the last half hour thinking positive thoughts about the hair on my cat evolving into feathers. It didn't work. The previous hour was spent trying to think her hair into scales.
Perhaps I just don't have Depak's mind power, or I'm not positive enough, but how the hell can I research scales to feathers if I can't conjure a starting point?
Are you sure his technique actually works?
"Sometimes life takes a creative leap that's almost miraculous. Nobody knows how this happens, and it can never be predicted."
Wasn't this the premise for the X-Men movies?
You'd never know looking at light that it could morph into matter. Yet it can.
You'd never know looking at solid wax that it could morph into a liquid that pores like water, or a gas that would burn in a wick and give us light. Yet it can--and anyone who knows more than a smattering about Descartes knows of this example.
You would never know looking at a tadpole that it could turn into a frog, and still it does.
In other words, one really can't look at something and, without any knowledge from experience, know what can become of it. Looking at a feather, it's really not at all hard to see how it could evolve from scales, since both are of much the same materials, and share significant form as well.
And evolution simply does what it does, sort through unexpected (not always totally unexpected, to be sure, but the entire set is not expected) mutations. Takes a sheer moron not to realize why evolution isn't exactly predictable. Is society predictable? Is ecology? Complex systems aren't predictable, and only a tard like Chopra would point to each complex system and gawp at its unpredictability.
Glen D
http://tinyurl.com/2kxyc7
Deepass Chopstick strikes again!
I may not understand evolution correctly. I am not a scientist.
But you all seem to be very lenient ol' Deepak; even you yourself PZ.
In the first three sentences, he makes three bad errors.
First is that life "take a creative" leap (notice he )
"Sometimes life takes a creative leap that's almost miraculous. Nobody knows how this happens, and it can never be predicted."
From what I understand, biologists DO know "how it happens". It is evolution by random variation plus natural selection.
The quote also seems to imply that these "miraculous creative leaps" are always advantageous, which from what I understand, is not the case at all.
The other error is 'it can never be predicted'; I understand that the exact "leap" can never be predicted, but the fact that a leap can and will occur is absolutely predictable.
I also noticed that in the article, he never says the word "evolution".
Forgive me if this question was already asked in the previous 71 comments (I'm supposed to be working so I don't have time to read them all:)
If Juravenator was not feathered but is nested within species that are feathered, isn't our nested hierarchy broken and common descent falsified for this particular grouping of animals? I always make a big deal about the consistency of the nested hierarchy we can group species as evidence for common descent, so how is it we are ignoring when that hierarchy is broken?
Obviously Deepak is much smarter than all of us because he is wealthier than all of us. That's how I know Miley Cyrus is smarter than we are.
If Juravenator was not feathered but is nested within species that are feathered
Juravenator is a genus. It's not going to be nested within a species.
And if whales lack a covering of fur or hair (I believe all have a few hairs, but you'd not know that if all we had were their bones) yet are nested within "mammals" which have fur and/or hair, does that falsify the predictions of evolution that nested hierarchies will be visible (where lateral gene transfer is not common)?
Organisms may very well lose features, often without too much difficulty. I am not sure how anyone knows that Juravenator doesn't have feathers (skin impressions?), but I am quite sure that they don't know that there were absolutely no feathers on it at any stage in life. Yet what if it had absolutely no feathers on it at any stage in life? Maybe it lost them because it lived where it was extremely hot, much as appears to be the reason why we lost most of our hair.
It's evolution, meaning that things change. Nested hierarchies are not dependent upon every feature being shared, but by one or more distinctive feature. Thus, blind cave fishes continue to group with sighted fishes.
Glen D
http://tinyurl.com/2kxyc7
I suppose the whale example is a good one. I guess when I read it I assumed the Juravenator genus had normal dino scales, so that the idea that a feathered dino had its feathers morph back into scales seemed a bit unreasonable, though as I type this I am betraying my lack of experience with paleontology because given all we have is fossilized bones I don't know how paleontologies know anything about dinos. Maybe they didn't have normal scales, just not feathers either.
One criticism laid on me by creationists is that we don't actually have a nested hierarchy, we claim we do and then explain away every exception by assuming a morphological feature was lost (or worse, one was evolved along a different path). I usually brush this off and yet do get a bit concerned when in fact we do seem to be doing that very thing. I guess at the morphological level, things can be misleading, especially when you only have fossils. It is on the genetic level that will most likely not lie, ie if a species lost some trait, but is nested within a group with that trait, they had better still have the genetics to produce it, just broken, such as our ability to create Vitamin C. And as for convergent evolution, I hope all examples show clearly that similarity is superficial, with structures built with different materials and with a different underlining genetic basis revealing its historical development.
(written by someone neck deep in the religious community, having accepted common descent, and wishing every example was crystal clear to defend why I am a heretic)
Or for a better example, think of legless lizards. If you went just by the lack of legs, you'd classify them as snakes or some other "characteristic" legless organism.
But they're morphologically lizards (snakes are believed to have evolved from lizards, too, but much earlier, and so they have independently-evolved characteristics not shared with lizards). It isn't legs that make a lizard, it's a whole morphology (cladistically, though, it's generally a single feature that determines each branching, I believe).
Features may be gained and lost during the course of evolution. What is important is that lizards branched off from snakes at some point, and have evolved independently of them since. A loss of legs to adapt to certain environments is just a normal part of evolution.
Glen D
http://tinyurl.com/2kxyc7
"It was not feathered on part of the tail. For the rest of the body we don't know."
I don't care that part of the tail was shown to be unfeathered, as this does not point to an, "unfeathered dinosaur." Heck, if only the top of the head had feathers we would refer to it as, "feathered."
If we look at reconstructions of feathered dinosaurs as far back as the 80s, we often see many examples with the tails unfeathered, and the back, neck, and head feathered.
The paper was not about the fact that, "some regions were not feathered," on the animal, but that they were hypothesizing that the whole of the animal wasn't.
In short, I do not understand your response to what I said as being a clarification of anything on the issue discussed.
"I suppose the whale example is a good one. I guess when I read it I assumed the Juravenator genus had normal dino scales, so that the idea that a feathered dino had its feathers morph back into scales seemed a bit unreasonable,"
What we see as feathers and scutes, nature simply may see as scutes and their alter egos. For example, birds can be bred where regions become feathered where they usually are not, and so on. Also, different feather types can be altered into other types so feather type on similar regions of the same species of bird need not be uniform.
In other word, maybe we should not look at scutes and feathers as ancestral traits to one another. Instead it may be better for us to see them as different expressions of the same general set of genes, which end results appear morphologically different to us.
Evolutionary groups are based on many shared features, not just one. Most birds fly, penguins don't--but a million other aspects of anatomy, physiology and behavior show that penguins should be grouped with birds. Snakes don't have legs, but we can still see why their closest relatives are lizards, which do.
Common descent would be falsified if there were significant suites of features that gave conflicting indications of ancestry. If penguins had cold blood and live birth with placentas and various bacterial genes and used chitin instead of keratin--or something like that--it would start to look like they couldn't reasonably be situated anywhere on the evolutionary tree.
David M,
I don't think that's why he's citing the 1998 hoax. (He doesn't actually clarify his argument in that sentence, after all--he just says Archaeoraptor "fits the bill" for whatever it is.) I think he believes Archaeoraptor was claimed to be the first feathered dinosaur which ever existed. (Which it wasn't, of course, but it was claimed to be a missing link between flying and non-flying feathered dinosaurs. He probably misunderstood that claim.)
Which would be really really dumb. Not that Chopra isn't capable of that, but I'm willing to apply the principle of charity on this one.
But it may very well have had normal dino scales, since birds never lost their scales. In fact, scales and feathers share much of the same developmental pathway in birds, so that chickens can be bred up to grow feathers on their legs and feet where scales had been growing. This is one reason why it isn't all that shocking to understand feathers having evolved from scales--feathers actually use genes of scale development to develop.
But we do have it, and many creationists don't claim otherwise--Behe even accepts it without any design reason for it. One reason is that these nested hierarchies were found prior to evolutionary theory being developed, by Linnaeus. While it is true that he continued to use analogous, and not just homologous, features in his classification scheme, homologies dominate to a degree that most of the basic outlines of his nested hierarchies remain today, if somewhat modified.
I do not see that we do so at all. Even Paley remarked on how sea mammals are alike to land mammals:
Surely it does not, although Paley might have been able to argue it at the time.
Seriously, don't get distracted by the specific details that they try to make support their ideas. The fact is that we have creationists pointing to the remarkable similarities between animals with dramatically different lifestyles. Paley couldn't think of a design reason for it, so he tried to claim that the Creator was following a "general plan," which hardly explains why said Creator followed quite different plans for the fairly dolphin-like ichthyosaur. Evolution explains it well. Design, not at all.
Only for certain characteristics. I like to bring up pterosaur wings next to bat and bird wings (hint, they're all quite different, both due to ancestry and to different evolutionary histories), since they show how there is absolutely no "common authorship" (there are some deep homologies, however) between the modifications of all three types of wings.
No, you cannot demand more of the record than is reasonable. While it is nice to see the vestiges of the past in our chromosome #2 (vestiges of telomeres in the middle, indicating the fusion of two chromosomes which occurred), and the broken vitamin C gene, there is nothing that would preclude either from being lost. The evidences are not single, you cannot have to demand that evidence for every change exists, but we know that the record of change is very extensive and very strong.
But they do, although you have to consider that the convergent evolution of the bat wing includes deep homologies as well. The cephalopod eye, also, is considered to be the result of "convergent evolution" (and the homologies there are very ancient and deep, thus not accounting for its similar form), and it happens to have blood vessels on the back side of the retina. Now we have adaptations which compensate for our "wrong-sided" evolution (the fovea is fairly clear of vessels), and actually see better than does an octopus, at least at the fovea, and birds have a pecten that is even better at compensating. But clearly the evolutionary differences are enormous. There's very few ways of making a lens, though, hence our eyes are fairly similar in form to cephalopod eyes.
Here's some of what I have blogged on the matter (have to paste in the addresses, since I don't want to be blocked for having more than one link in my post):
behefails.wordpress.com/2008/10/22/theres-a-reason-why-all-vertebrate-wings-are-modified-legs-of-their-terrestrial-ancestors/
behefails.wordpress.com/2008/10/20/evolution-of-adaptive-immunity-v-complexity-evolves-isnt-copied/
behefails.wordpress.com/2008/10/16/evolution-of-adaptive-immunity-iv-lawful-accidents-of-heredity-visible-in-adaptive-function/
behefails.wordpress.com/2008/10/11/evolution-of-adaptive-immunity-iii-it-has-the-marks-of-irreducible-randomness/
behefails.wordpress.com/2008/10/07/evolution-of-adaptive-immunity-i-phylogeny/
I like the first address above, since it asks the question for which no IDist has ever given me an answer--why are all vertebrate wings modified legs of their terrestrial ancestors? Or in other words, why do even bird wings "nest" with dinosaur legs, and not with the wings of other vertebrates? There is no design sense to that at all, while it is exactly what evolution demands in that context.
And the last one shows some of the molecular divergences found in the immune system. This is important because, as evolution predicts, there is no repetition of complex molecules (lateral transfers of genes are a different kettle of fish).
I disagreed above with the contention that molecular evidence must always be in evidence for changes. But what is a reasonable test is that the evidence that we do have must nest properly within organisms like most vertebrates, which typically do not transfer genes laterally.
Glen D
http://tinyurl.com/2kxyc7
haha...what a chump. im set to get the archaeopteryx fossil for my second tattoo. donations...anyone?
Glen,
Thanks for the links. I will take a look at them.
Pete
Scales, as opposed to feathers, are preserved on part of the tail and I think just above the feet. Nothing is preserved on the rest of the body, so we don't know that it wasn't feathered there.
Convergence and reversals are expected from the mechanisms of evolution (mutation, selection). When you apply Ockham's Razor, you find that a nested hierarchy remains nonetheless. Suppose Juravenator really did lack feathers all over its body: so what, feathers are just one character -- one character cannot tell us much about relationships; we must look at the whole animal (or at least at everything that's left of it).
One feature could be enough, but that doesn't happen often, especially not when your data matrix is actually big enough to be halfway reliable. That's because the fossil record is famously incomplete.
I wasn't defending the interpretation by Göhlich & Chiappe. I was attacking it. Precisely as you say, finding scales on part of the tail does not mean the whole body lacked feathers.
Would surprise me.
No, it merely means he doesn't read Nature.
(...And that he should read Nature instead of shooting his mouth off once again.)
Bingo.
You could have kept the http:// part and thus turned the addresses into clickable links. The ScienceBlogs software only looks for <a> tags.
Which one? There are ten (partial and complete) skeletons known so far.
I must be mildly dyslexic - when I first saw the header on this entry, I thought it said "Ignoring Flatulence" - quite apposite, really.
"I wasn't defending the interpretation by Göhlich & Chiappe. I was attacking it. "
Wow, I sooo did not get that. It really looked like you were trying to explain to me their reasoning.
not that i'm aware of, but i'd be very interested to see that.
clearly not, it's got capitals in it.
well, depending on what you call a bird, they did. microraptor had them, and archaeopteryx has indications that its ancestors probably did. (close examination shows flight feathers above the ankles, similar to microraptor)
because the idea that feathers evolved from scales is untrue. if anything, scales evolved from feathers. but the avian feathers on birds today are unrelated to the reptilian scales on lizards. it's a common claim that feathers evolved from scales; they didn't.
you don't see gliding distance as a selective factor in small arboreal dinosaurs?
wasn't intended to. but the secondary loss of foot feathers is pretty easily explained by a more terrestrial lifestyle. those things had to get in the way on the ground.
it's possible that (very primitive) feathers are a basal archosaur trait. it would explain quite a lot, actually. the other archosaur we haven't mentioned yet also seemed to have a sort of furry body covering.
those aren't velociraptors in jurassic park. they're deinonychus, which is a good deal bigger. but also probably had feathers. velociraptor is also not found in north america. the name mixup comes from greg paul's book, "predatory dinosaurs of the world" where he identifies the two as synonyms, and goes with the earlier name. the irony here, of course, is that paul rather consistently depicts all of his "velociraptors" with feathers. so crichton evidently read the book, without looking at the pictures.
*groan*
so "first feathered dinosaur" here means the "first feathered dinosaur that is not also a bird." how... silly. lots of feathered dinosaurs have been found. some of them birds, some of them not.
yeah, that's just silly. and... we have better specimens of microraptor now too.
different kind of scales. the scutes can become feathers, but the reptilian kind of scales on their feet cannot.
Lago (That be me) said: "I do not get how it was relevant to the conversation"
Arach responded: "because the idea that feathers evolved from scales is untrue. if anything, scales evolved from feathers. but the avian feathers on birds today are unrelated to the reptilian scales on lizards. it's a common claim that feathers evolved from scales; they didn't."
My response: There is NOTHING that I said that had claimed feathers evolved from standard reptilian scales. I always referred to the subjects as, "scutes and feathers." Your response to me does not make a lick of sense.
you also said above: " if anything, scales evolved from feathers. "
My response: There is also no evidence for this whatsoever, and this does not make a lick of sense either. Your own argument says how scales and feathers are not related to one another, unless you are inconsistent and using scales as a vernacular for scutes here despite your previous statements that attempts to separate the word usage.
Lago said: "Needing" does not indicate a source for feathers,"
Arach responds: "you don't see gliding distance as a selective factor in small arboreal dinosaurs?"
My response: The above implies you are stating feathers first evolved to assist gliding in small arboreal dinosaurs. If you do not believe this is claimed above, please re-read all the comments up until this point that preceded the above statement. Yes, I know you have given previous reasons not related to flight and gliding for the selective origin of feathers, but that does not take away from the above statement that clearly suggests otherwise. Also, needing still does not give a source, only possibly a selective pressure once a source is in place and actively producing the variations being selected upon.
Lago said: "or a selective force for deriving scutes from a feather precursor."
Arach responded: "wasn't intended to. but the secondary loss of foot feathers is pretty easily explained by a more terrestrial lifestyle. those things had to get in the way on the ground."
My Response: Again this implies feathers evolving in the trees first, and for an arboreal lifestyle, and it does so for the ancestors of all crocs, as well as all dinosaurs. Is this really your position? Evidence for if so? It also does not explain why you had brought up the "wind tunnel tests" on M. gui? In the context of our discussion on which came first, scutes or feathers, how are these tests relevant? It also does not explain how the secondary loss of feathers on the feet of feathered theropods got transferred to crocs, since, in your argument, scutes are derived after the fact, not before? Can you see this flaw? There is no way for you to save this argument without stepping on everything else you have claimed in numerous ways. If need be, draw-out what you have claimed on paper and see what a mess it is.
Lago said: "Also, more relavant to the conversation, Scutes are found in crocs, dinosaurs and birds, and the dino-croc split is almost certainly way before birds showed up. Are you implying crocs, or their ancestors, used to have feathered hands and feet? If you are to be consistent, I think you must."
Arach responded: "it's possible that (very primitive) feathers are a basal archosaur trait. it would explain quite a lot, actually. the other archosaur we haven't mentioned yet also seemed to have a sort of furry body covering."
Sure it is possible, but evidence for? And please stop using the, "default argument," without first answering to the flaws I pointed out in that position.
yall all have way to much time on your hands...
I got where the misunderstanding lies: in comment 70, where I answered to
, I agreed with this quote and explained why: while Göhlich & Chiappe speculated that the animal was featherless all over, we don't actually know that -- we only know it had scales on part of the tail (and apparently part of the legs).
I sometimes do that (agreeing with a quote rather than disagreeing with it). :-)
What arboreal dinosaurs?
Not necessarily -- perhaps it was possible to fold them away to some degree. Keep in mind the phalangeal proportions and toe claw curvatures of Microraptor are just barely on the scansorial side of things.
You too. After all, you just read a blog post and 94 comments.
(Surely you don't want to imply you commented without reading all previous comments?)