A little more than halfway through the horror novel The Relic, a blood-spattered tale of a monster lurking in the bowels of the American Museum of Natural History, the scientist Greg Kawakita shows off his evolutionary extrapolation program to his colleague, Margo. It is a complex analysis system designed to take two DNA samples and spit out a hypothetical intermediate creature, essentially extrapolating what their common ancestor must have been like. In a test run, Greg has the computer scrutinize the DNA of a chimpanzee and a human;
Intermediate form morphological characteristics:
Gracile
Brain capacity: 750cc
Bipedal, erect posture
Opposable thumb
Loss of opposability in toes
Below average sexual dimorphism
Weight, male, full grown: 55kg
Weight, female, full grown: 45kg
Gestation period: eight months
Aggressiveness: low to moderate
Estrus cycle in female: suppressedThe list went on and on, growing more and more obscure. Under "osteology," Margo could make out almost nothing.
Atavistic parietal foramina process
Greatly reduced iliac crest
10-12 thoracic vertebrae
Partially rotated greater trochanter
Prominent rim of orbit
Atavistic frontal process with prominent zygomatic processThat must mean beetle browed, thought Margo to herself.
Diurnal
Partially or serially monogamous
Lives in cooperative social groups"Come on. How can your program tell something like this?" Margo asked, pointing to monogamous.
"Hormones," said Kawakita. "There's a gene that codes for a hormone seen in monogamous mammal species, but not in promiscuous species. ... The program uses a whole arsenal of tools - subtle AI algorithms, fuzzy logic - to interpret the effect of whole suites of genes on the behavior and look of a proposed organism."
Fuzzy logic, indeed, but while this is science fiction Richard Dawkins apparently believes it is possible to gain insight into what our last common ancestor with chimpanzees was like through similar methods. In response to the 2009 Edge question "What will change everything?" Dawkins replied (in part);
1. The discovery of relict populations of extinct hominins such Homo erectus and Australopithecus. Yeti enthusiasts notwithstanding, I don't think this is going to happen. The world is now too well explored for us to have overlooked a large, savannah-dwelling primate. Even Homo floresiensis has been extinct 17,000 years. But if it did happen, it would change everything.
2. A successful hybridisation between a human and a chimpanzee. Even if the hybrid were infertile like a mule, the shock waves that would be sent through society would be salutary. This is why a distinguished biologist described this possibility as the most immoral scientific experiment he could imagine: it would change everything! It cannot be ruled out as impossible, but it would be surprising.
3. An experimental chimera in an embryology lab, consisting of approximately equal numbers of human and chimpanzee cells. Chimeras of human and mouse cells are now constructed in the laboratory as a matter of course, but they don't survive to term. Incidentally, another example of our speciesist ethics is the fuss now made about mouse embryos containing some proportion of human cells. "How human must a chimera be before more stringent research rules should kick in?" So far, the question is merely theological, since the chimeras don't come anywhere near being born, and there is nothing resembling a human brain. But, to venture off down the slippery slope so beloved of ethicists, what if we were to fashion a chimera of 50% human and 50% chimpanzee cells and grow it to adulthood? That would change everything. Maybe it will?
4. The human genome and the chimpanzee genome are now known in full. Intermediate genomes of varying proportions can be interpolated on paper. Moving from paper to flesh and blood would require embryological technologies that will probably come on stream during the lifetime of some of my readers. I think it will be done, and an approximate reconstruction of the common ancestor of ourselves and chimpanzees will be brought to life. The intermediate genome between this reconstituted 'ancestor' and modern humans would, if implanted in an embryo, grow into something like a reborn Australopithecus: Lucy the Second. And that would (dare I say will?) change everything.
[Dawkins' response was taken from here, as his answer does not appear on the official Edge webpage.]
I am not going to consider points 1 and 2 in detail. I too sincerely doubt that there is any other species of hominin hiding in some uncharted part of the world, nor can I imagine how a natural human-chimpanzee hybrid could ethically be produced even if biologically possible. (And what would such an experiment show that we cannot already glean from DNA on paper?). Points 3 and 4 are more interesting, even if they are fundamentally flawed.
The problem with #3 (a specially-designed "chimera") is that scientists would be combining different percentages of human and chimpanzee DNA to produce a particular result. I imagine that the percentages could be tweaked this way or that (assuming this is possible at all) to get the recipe "just right." Too ape-like? Throw in some human DNA. Too human-like? Some more chimpanzee genes will fix that. Rather than working with pencil or paint these "artists" would be trying to reconstruct a creature via genetics and their own biases would certainly shape the product of their endeavor. (And then there's the question of what to do with the "rejects.") Even though Dawkins is primarily considering ethics on this point the next one makes it clear that what he has in mind is the creation of a proxy for the last common ancestor of chimpanzees and humans.
Indeed, point 4 is what made me think of Kawakita's program in The Relic. Dawkins is assuming that if you start with two living organisms and think up (or engineer) a creature intermediate between the two you automatically have a fair approximation of the last common ancestor between them. This is sloppy logic, at best, and even Charles Darwin recognized that this mode of reconstruction was fraught with problems. In On the Origin of Species Darwin wrote;
In the first place it should always be borne in mind what sort of intermediate forms must, on my theory, have formerly existed. I have found it difficult, when looking at any two species, to avoid picturing to myself, forms directly intermediate between them. But this is a wholly false view; we should always look for forms intermediate between each species and a common but unknown progenitor; and the progenitor will generally have differed in some respects from all its modified descendants.
This is why the fossil record is so important (even though Dawkins belittles it in the beginning of The Ancestor's Tale). Fossils provide important tests of what we hypothesize based upon present conditions, and Darwin was right to emphasize that in our search for the form of common ancestors we are looking for creatures intermediate between a particular organism and an unknown ancestor, not between living species.
Let's apply this to human evolution. There are presently three hominids (Orrorin, Ardipithecus, and Sahelanthropus) that are in competition for either the oldest human or closest to the last common ancestor of humans and chimpanzees. It is very difficult to tell where each belongs. Does each represent an early human, a chimpanzee-line hominin, or a hominid that is close to the human-chimpanzee last common ancestor but not a hominin itself (like how Proconsul is a catarrhine close to apes but not an ape itself)? From the available evidence, however, none of these creatures appears to be "intermediate" between living humans and chimpanzees. If one of them is (or is close to) the last common ancestor they rend Dawkins' proposal useless.
Furthermore, I can only wonder why it would be intellectually profitable to create a test-tube "humanzee" hybrid. Scientists could prove that they could make one, surely, but it could not be justifiably stated that we have brought the human-chimpanzee LCA "back to life." The ethical questions of how to treat such a creature also need to be considered. As Craig Stanford stated in his book Significant Others given our present state of understanding it is questionable to keep apes in captivity and unethical to use them for medical research. Surely the scientists who would create a humanzee hybrid would not want to just look at it, but how do you ethically care for a human-engineered aberration that has never existed before?
I find Dawkins' humanzee thought experiment rather strange. Is this not the man whom many people currently identify as the public face of evolutionary science? Perhaps so, but in his ruminations on what might "change everything" he appears to have fallen into a trap that Darwin had recognized 150 years ago. Combining chimpanzee and human DNA, no matter how you try to do it, will not resurrect our last common ancestor with them. The branching pattern of human evolution would not lead us to expect otherwise, and the real clues as to the appearance of the human-chimpanzee LCA are probably still locked in the rock of Africa.
[Hat-tip to moneduloides]
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Perhaps the kindest thing to do would be to assume the Dawkins was not proposing actual biology, but was commenting on ethics. Those who hold human life to be "sacred" have little solace in science.
From the way I read Dawkin's piece, I don't think he's actually concerned with accurately reconstructing our LCA with chimpanzees (he even refers to only an 'approximate' reconstruction himself) for scientific gain - his point, rather, seems to be providing practical proof of the interrelatedness of humans and other animals: "Theoretically we understand this. But what would change everything is a practical demonstration..."
So he doesn't seem to claim that a lot of scientific knowledge could be gained by creating such a hybrid, but that it could serve as visible, tangible evidence - it would hammer the point home in a way that more abstract evidence can just not do. "It would change everything" thus probably refers to society at large, not science in this context.
See? Scientists can't agree on evolution whatsoever, so that just goes to show that evolution is false, and obviously the Bible tells the true origins of mankind!
/Poe
There is a story that a group of researchers partied too much, and impregnated a female chimpanzee with human sperm. The female chimp showed every sign of early pegnancy. The group sobered up and dosed the chimp with hormones. The pregnancy, if any, terminated. I heard the story, compete with names, from someone who heard it from someone who was there. Sorry, I don't remember any of the names.
I vaguely remember a 50's or 60's novel about Australopithicenes being enslaved. I think the hero impregnated a female to demonstrate that they were the same species as us and thus should not be enslaved. He may have been on trial for bestiality.
Reconstructing character states (e.g. genes) in the LCA of two extant species is actually very slightly more complex, as outgroup comparison is necessary. Darwin could sense that intuitively (it seems), but not articulate it. Dawkins knows it, of course, but that is not what he was talking about; the 'everything' that would be changed by the possibilities he mentions is the view that humans are a separate moral order in an essentialist way (due to being created separately from 'animals', 'ensouled' post-hoc, or whatever).
This sounds like a cross between "Jurassic Park" and "Frankenstein." Though I'm a fan of Dawkin's writing,this "humanzee" concept is morally questionable, impractical, and even if it was successful, would probably end up telling you nothing in the end.
Interesting stuff. I'll be honest - I've never read any of Dawkins' books from cover-to-cover, not because they weren't interesting, things just got in the way.
I think it is true that he is the public face of evolution for an awful lot of people. It would be comforting to know if the views of the "face of evolution" actually jive with current evolutionary thinking.
Your post implies, to me anyhow, that Dawkins and/or Edge were hiding his response. However, the article was posted on Richarddawkins.net since 10 January.
I'm with John Scanlon on this. The "everything that would be changed" in Dawkin's example, was clearly the perception of humans as being distinct from their close "animal" relatives. (It also would seem that this is a bit of a poke at those who still maintain anthropomorphic views
Just some a quick comment on "working from paper" in point 4: Realistically, you wouldn't get far as development is a process and too little is known about the interactions between the factors encoded in the genome. While the genome might encode the elements in the process, it is the interplay of the factors across space (different cells, polarity gradients, etc), time, etc., that make the process work. Furthermore, different cell types effectively have different genomes, in that different sets of genes are available for expression at different levels.
A humanzee wouldn't be a great model of a human ancestor since chimps aren't ancestral to humans . . . and don't they have more genetic variation that human populations (just not as visible to the naked eye)?
Can bioinformatics algorithms do something like this already - ie given a set of current nucleotide sequences construct a "most likely last common ancestor"? Or is the problem generally too underconstrained to be soluble?
> The problem with #3 (a specially-designed "chimera")
> is that scientists would be combining different
> percentages of human and chimpanzee DNA to produce
> a particular result.
A chimera is not an organism with a single population of cells with hybrid DNA, but an organism with with two or more populations of of genetically different cells that originated in different zygotes. The human and chimp cells in Dawkins' (mercifully) fictional chimera would have their original, unaltered DNA.
csrster,
(Before I start, realise I'm simplifying horribly and generalising wildly in writing this to try reduce it down to a few words. I'm going to use computer engineering as an example, just guessing that you know a little about that.)
The point I was trying to make is that knowing an ancestral sequence wouldn't be enough. Growth of an animal (insect, plant, whatever) is a process and you can't "predict" that process from the sequence by itself. Maybe one day, but that day will be a very long way off!
People are trying early efforts to model smaller, simpler systems, like the developmental of small parts of the body or the early stages of the development of an embryo. This work starts with already knowing what are the molecules controlling the development of the part of the body being studied. You can't figure that out from genome sequences on their own. The model then uses data on how these molecules interact. This also cannot be worked out from the genome sequences on their own.
As a hypothetical example, you would want to know all the homones used, what receptors they bind to, and the strength which they bind, then the genes that those hormone receptors "turn on" or "turn off", what these genes make, what they bind, and so on. None of this information can be gotten from the genome sequence by itself.
(Optimists will say "yet"! In principle one day we may be able to. One day a long time from now, though.)
There are more complications, but I think I've given enough already to get you started. I could make up analogies, but I hope you can follow this as it is.
Marek,
Current research is invariably a little further ahead, but also less certain. It's one of the frustrations of scientists: seeing tentative science reported as (near) certainty. Dawkins at least will know when to back off and wait up until the rough edges are knocked out.
Whoops, remove my second sentence. (I'm going to use computer engineering as an example, just guessing that you know a little about that.) I decided to drop the analogy and write directly. Bad editing: I have to rush back to work, etc.
As far as I remember, the humanzee thought experiment was more about undrawing the line between human and the other great apes. Really a discussion about questionning the cultural aspect of delineating humans as really more special than the other apes.
So I guess it was more a take on reconsidering the place of great apes as living beings both on a biological ground and from a cultural perspective.
I wish we could know about humanzee. But this is considered so unethical... The striking thing is that most people will consider it unethical because, you know, human and chimps are more than just different (closely related) species. While the only worry in my opinion is that if the humanzee is able to fully develop, and if it is able to develop conscience, then he/she will have to face the fact of his/her existence being the result of a scientific experiment.
People with whom I discuss my almost lack of negative feelings about the humanzee experience make another scare move when I tell them that whenever we would do the experiment, we should try to have many individuals so that humanzees would feel less lonely. I wouldn't feel threatened coexisting with another intelligent species personnally (people do like dolphins and elephants a lot after all, right?), while I would find this very fascinating. Welcome new friends!
Ethics, did you say ethics? :-)
"I vaguely remember a 50's or 60's novel about Australopithicenes being enslaved. I think the hero impregnated a female to demonstrate that they were the same species as us and thus should not be enslaved. He may have been on trial for bestiality."
That would be "Les animaux dénaturés" by French novelist Vercors. Don't know if there's an English title; but it was adapted, rather poorly from what I heard, into a movie called "Skulduggery".
It's about the discovery of a species of "apemen" called the Tropis (from "anthropoid"). Are they human or not? If they are, they have rights, but if not, they can be bought and sold, exploited, or killed. All the usual philosophical definitions of humankind are tried, but they give no clear answer. So the hero impregnates a female Tropi, kills the baby once it's born, and denounces himself. And the court has no choice but to settle the debate by deciding whether he's a murderer or not (of course the trial has nothing to do with bestiality as it is not punished by the law).
Really a fine book.
Some comments on hybrids from experience with fish hybrids. When you examine the hybrids, you find for some characters they are like one parent or the other. For others, they are intermediate. For yet others they extralimital or novel. Hybrid vigior sort of thing; consider mules.
Yes, thats the novel I was thinking of. I recall reading it in paperback, in English.
Wow, Dawkins seems to be catching a lot of criticism from the blogosphere this week; Iâve gone several rounds defending his Mt. Improbable analogy at another site.
Anyways⦠My interpretation of the article pretty much coincides with the majority opinion expressed here, that Dawkins was speculating as to advances that would force humans to redefine their relationship with nature. The intent of the Edge article was to generate interest through shock and awe â Iâd say it worked!
I read Ancestorâs Tale a while back â I donât recall any belittling of fossil evidence. Seems strange that Dawkins would belittle fossils, but Iâll have another look. Iâm guessing that it was during the âMitochondrion Eveâ discussion???
Johnny, from what I remember the belittling of fossils was more to do with the misconception that the fossil record is the only evidence of evolution, and therefore gaps in the fossil record = failure of evolution. He said that even if there were no fossils, we would still have overwhelming evidence for evolution.
Basically, fossils are cool, but they aren't everything.
I will speak of yetis etc.
At present our knowledge of bipedal apes is based on what we've learned of hominins, but not all bipedal apes have been hominins. Based on eye-witness reports and photographic/film evidence, yetis and similar animals show features not seen in or extrapolated from such physical hominin remains as we've found.
O.K. - I'm following you now...
Thanks jefrir
From the drift of your many posts, it seems you are dealing with the other guy's gay-tinted debate, on his terms and on his ground... You are fighting him from the insides of his lies...
Step out of his box, and fight him with your own terms and grounds, from truth...
Quote: "I wonder if the creationists are evolving?"
_____________________________________________________________
They can't... Their whole world began a month before "Christ", and ends in "Armageddon", a few years from now.. making Life and evolution a two thousand year start to finish process.. "then there is nothing"... And the weird of it, is that they are actually building their own insane Armageddon for themselves (and for us, whether we want it or not), they are desperate to fulfill insane prophesy, minute by minute, just to prove their lies are correct.. lead by America's insane Inquisition against non-believers and drug using people, because those basic mind stimulants make people see the truth through religion's lies... They are destroying the planet to prove themselves correct.. believing Life is bad, and Death is good... What they deem "evil" they are desperately trying to destroy, which is pretty much all of Life... They even pray in hell, to their pretend gods... Christianity is like a bunch of naked natives, stoned on kavakava and bio-anesthetics, dancing up a fever around a great bonfire, painted in colored muds, screaming obscenities at every thing that isn't just like them... They live in a Box.. the bottom of their box is "Hell".. the top of their box is "Heaven".. the sides of their box is "life began in a seven day project", and "life ends in a "Judgment day", when the rotted corpses of good people and the bad people all crawl-up from their graves, and fly into their lovely heaven... Everything else in Life is considered to be garbage to them... They treat everything not like them to be evil garbage... It be Insanity as big as it gets...
Religion has put the brakes on evolution to prevent anything new from happening ever again, so they won't have to process new thoughts.. because their religion conditioning makes their heads hurt when they think beyond 7% mind usage... They are destroying the planet because their religion makes their heads hurt when they try to think truth beyond their bible's lies... Their religion needs them to kill evolution, because evolution means that there might not be a place in the future for religion.. so religion has prevented the future from occurring... Religion wants everything to remain as it is forever.. is what is killing humanity, because religion believes that Death is preferable to Life...
They can't... Their whole world began a month before "Christ", and ends in "Armageddon", a few years from now.. making Life and evolution
An humanzee would not change anything. Not much would be really known, and for people that see humans as somehow inherently separated for animals, that would be just a monstrosity made by heathens playing god. Probably they would split on whether it was a poor man or just an animal, the same way they once were (albeit there is still some small divergence on that) regarding black people as humans, descendants of Adam (even thought maybe cursed) or pre-adamic souless beasts, just like the others created before Adam. For the non-neo-medieval part of the world, that would be just an immense scandal of bioethics, more than anything else.