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Chimps Belong in Human Genus?
Bradley Chapman writes "I found this interesting story from Discovery News about our ties with chimpanzees. Excerpts: 'Chimpanzees share 99.4 percent of functionally important DNA with humans and belong in our genus, Homo, according to a recent genetic study.
Scientists analyzed 97 human genes, along with comparable sequences from chimps, gorillas, orangutans and Old World monkeys (a group that includes baboons and macaques). The researchers then took the DNA data and estimated genetic evolution over time. They determined that humans and chimps shared a common ancestor between 4 and 7 million years ago. That ancestor diverged from gorillas 6 to 7 million years ago.'" Genus is the next step up from species, if you recall your taxonomy. Humans are the only living species in genus homo, currently.
to see if they can make babies?
What I have always wondered -- if you can cross a Horse, zebra, or donkey -- couldn't you cross a human with a chimp? Has anyone ever tried this?
Is there some web page out there that has information on this?
I am curious.
Not that I am curious enough to try :)
Agreed. Another question, one they didn't address, is how far removed from other apes we are. 99.4% of a couple quadzillion genes still leaves a lot of genes that define us as humans. And if an orangutan is 89.7 % (an arbitrary number on my part) the same as a human, that speaks somewhat to the relativity of the 99.4% number of the chimp. Also, how far off are we from one another?
Having said all that, I think that all the ape species deserve somewhat more respect than we've been giving them...
The Spoon
Updated 6/28/2011
The question is, while they evolved, did their genome evolve in a direction similar enough to our own to warrant including them in the genus homo?
To me, it just seems to be an argument debating the differences between genotype and phenotype.
What's this Submit thingy do?
Its interesting that we decide they belong in our Genus and not that we belong in theirs.
t
Actually, it doesn't matter whether we use only Homo or Homo and Pan for the lineage of chimps&humans, since both genera include a monphyletic lineage. For phylogenetic taxonomy, it's matter of taste, mostly. MY taste is that there is no need to introduce changes.
Supergenus Gorilla
* Genus Gorilla
- Gorilla gorilla
Supergenus Homo
* Genus Homo
- Homo sapiens
- Homo neardenthalensisâ
- Homo habilisâ
- Homo erectusâ
[- Homo demens (e.g. Bush & al.)]
*Genus Pan
- Pan troglodytes
- Pan paniscus
[Caveat emptor: I did this from memory, there might be a mistake somewhere]
The fact is, it doesn't mean a thing to use genus, supergenus, or subgenus. What matters is that the lineage chimps&humans is monophyletic, that is, that chimps and bonobos are more closely related to us than to gorillas or orangutans.
``L'imagination au povoir.''
I'm sure the creationists will pitch a fit if chimps are reclassified.
Any purist creationist gets annoyed if you just say DNA... but they're easily discredited. The intelligent ones will simply shrug because it doesn't matter in the slightest as far as their faith/belief goes. The middle majority will be disquieted by it at the very least, which is probably true for how most people will feel regardless of their creationist/evolutionist/whatever leanings.
I wonder if there would be any legal ramifications regarding the rights of chimps compared to other animals.
Certainly various animal rights activists will use this as a rallying cry to stop experimentation on chimpanzees. Of course, you can make the counter argument that because they are the closest to us genetically they are also some of the best test subjects. Unless, of course, the aforesaid activist would like to volunteer for stage 1 drug testing... no? Didn't think so.
OK, we're better at manipulating our environment than chimps. But that's just one evolutionary adaptation among many. All our non-slackerness has bought us is a few thousand years of population runnup (practically an eyeblink, on the evolutionary time scale), which will probably be followed by an even faster dieback, as we overrun our resource base and saturate our environment. Not the most impressive evolutionary accomplishment!
1) You are obviously correct.
2) Species is most often defined: If two animals can and do interbreed, then they are the same species.
So, they argue, timber wolves and huskies are physically separated, if not genetically separated, and are thus different species. Huskies and poodles are not physically separated, so they are not different species.
Of course, this is a ludicrous argument, because poodles/huskies/great danes etc. were all recent man-made breeding experiments, derived from wolves under 5000 years ago. If they're really all that separate, they've only been separate momentarily.
There are no trails. There are no trees out here.
Speech is a misnomer. They are able to communicate via hand signs (ASL, for instance) if trained.
They are able to lie and insult others.
They seem to get to 3 years old intelligence and stop there.
http://www.cwu.edu/~cwuchci/quanda.html: Washoe, the most accomplished signer, has a vocabulary of 240 "reliable" signs...The chimps use the signs both singly and in combination with other signs in multiple-sign utterances. So far, one of the longest utterances observed has been a sentence of seven different signs...They have demonstrated an ability to invent new signs or combine signs to metaphorically express something different, for example: calling a radish CRY HURT FOOD or referring to a watermelon as a DRINK FRUIT. In a double-blind condition, the chimpanzees can comprehend and produce novel prepositional phrases, understand vocal English words, translate words into their ASL glosses and even transmit their signing skills to the next generation without human intervention.
..., but think that putting humans and chimps in the same genus is pushing matters slightly.
Why? I don't see why they should be either separate or included. Genus is supposed to be a grouping that is inclusive on ancestry, but I don't know of any standard that says just how similar to species have to be to be considered a part of the same genus. So I can see a genus consisting or merely humans, of humans and chimps, or of humans, chimps, and gorillas. Once you get past that, you are basically including all primates (what's the sense of including oragutangs but not gibbons?). But nowhere do I see a clear dividing line.
If we say a genus should be larger than merely one species, then Chimps should be included... but what's the basis for that?
I think we've pushed this "anyone can grow up to be president" thing too far.
Creatures even more closely related to humans, actually our ancestors, are also classified in a seperate genus. The Australopithicines are our earliest ancestors following the divergence of chimps from our lineage. They, though closer, are in a seperate genus, so it makes little sense to classify chimps into the same genus as we are.
Ever watched any behavioral studies on chimpanzees?
It might frighten you how much of their behavior they have in common with us.
Chimpanzees have been observed
- participating in sex for pleasure (oral and otherwise),
- organizing hunts for food (they happily kill and eat other monkeys or smaller animals),
- teaching their young how to use tools (slowly and conscientiously - not haphazardly expecting the kid to just "pick it up")
- physically assaulting (and sometimes killing) a fellow group member for no discernible reason.
Sound familiar? It should. Just check out your regular TV news shows to have a keen understanding of the human savagery mirrored in chimp society.
Yeah, I think they are worthy of being included in our genus.
blue
This is kinda old news, it was covered in the book The Third Chimpanzee by Jared M. Diamond. He talks about the similiarities in the genome, plus the differences that do exist in other traits. He maintains that chimps, bonobos and humans belong in the genus Trogolodyte, but humans made the genus Homo because they didn't really want to think of themselves so close to the chimps. Really interesting book though.
Not just another kingdom - but a taxonomic level above kingdom has been added. This is the domain level, and was introduced because of the research of Carl Woese. He found, through genetic sequence comparisons, that non eukaryotic organisms (prokaryotes) are comprised of two groups (bacteria and archae) that are as different from one another as both are to eukaryotes. A good picture and explanation can be found here.
The strength of the old taxonomic systm is that it is extensible, but it depends on a few suppositions which have been shown to be false. One of the suppositions is that there are a finite number of well-definable species which were created and will always remain exactly the same. Charles Darwin questioned this supposition by pointing out species which appeared to be transitional, and which were extremely difficult to classify in one category to the exclusion of another. Such were usually called "subspecies" and were presented as evidence for the theory of natural selection in The Origin of Species. Darwin theorized that these subspecies were in the process of changing from one form to another.
Evolution poses a serious problem to a finite taxonomic system. After Darwin's theory was widely accepted, biologist began viewing biological diversity as a spectrum rather than as quantized sets. So how do you classify a spectral array? The electromagnetic spectrum is broken into regions, like IR, UV, microwaves, radio waves, the visible spectrum, etc. These boundary regions are not well-defined and tend to change from textbook to textbook. That's sort of what phylogenists are doing these days. Most have given up on unambiguous categorization, and are concentrating instead on making taxonomy consistent with evolutionary descent. Each taxonomic group should (theoretically) descend from a common ancestor. That's harder than it sounds, but genetic data is a powerful tool in figuring out lines of descent. Genetic data has provided quite a few surprises so far about who's related to whom.
"... you need to interbreed them. If they can produce male and female fertile offsprings, then they are same species."
... but it seems that it can happen which means the above test isn't 100% accurate.
I saw something on Animal Planet the other day where a baby Tiger-Lion mix was born and was fertile. They noted how this was extremely uncommon
> It should be obvious to any cretin that there is a definite qualitative difference between human and chimp, indeed between human and all of (observable) nature. And that supposedly insignificant quality makes all the difference. The fact that we cannot (yet) measure its true magnitude in scientific terms does not make it any less ridiculously obvious. No human is just another monkey. Not even you.
So, is the chimpanzee intellect more similar to the human intellect or to the sea slug intellect? Or to the intellect of a rock, since you want to make us special with respect to "all of nature"?
Were merely an extremum along one dimension of measure that we're inordinately proud of. Chimps probably scoff because we don't have thumbs on our feet, and rocks because we're so fragile. Who's the fair arbitrater of excellence?
Sheesh, evil *and* a jerk. -- Jade
"99.4% of a couple quadzillion genes still leaves a lot of genes that define us as humans."
I think 99.4% is pretty damn close, for a moderate number of randomly choosen genes. Since it's scientific research, one would think the (independent) referees of the paper will have looked at the STDEV. It was published, so that should be OK. We will not find anything closer (on this planet, that is).
Your comparison is wrong. A computer is build on the logic of on (1) or off (0). This number of states does not say *anything* about the complexity you can build with it. Think about 35.000 genes (the approx number of human genes). Think about all combinations, think about regulation and feedback loops between these genes. Think about transformation from DNA into protein and other structures, creating cells, creating organs, creating an organism. Think about interaction with the environment of all of this stuff.
Maybe then you will start to appreciate that the number of genes doesn't mean a lot. Hell, one could build something rather incomprehensibly complex with just a couple of hundreds of genes.
As for judgement which organism is more evolved, human or man, well that depends who's side your on. Philosophy: there is no wright or wrong to things - it is just the interpretation of the observer. There is no good measure for complexity. If you measure it by succes of a species, bacteria would win. They far outnumber us and any other living organism.
IANAL, but imagine a beowulf cluster of in Soviet Russia all your belong are base to us welcoming the new SCO overlords.
ISTR hearing that one of the most commonly shared, and least mutated, genes known has something to do with how DNA gets coiled up into chromosomes.
Those are the histone proteins, and you are exactly right about them being the most conserved genetic sequences. Only makes sense, since DNA double-helices are only have variations in lengths and on the inner sides of the strands, and any changes in the histone structure can affect anything the cell tries to do (replicate, produce proteins). Just about any biochem or molecular biology text will reference that, but I read it in either Voet & Voet or Lewin Back In The Day.
Additionally, the similarities between humans and any eukaryote are enough to make you feel either very unimpressed about your genes or very impressed with the differences that small things can make, especially in combinations with each other and a nice long developmental stage.
"Bugger this, I want a better world." - Jenny Sparks
Well, his distinction made sense to me. If you can produce viable offspring, then it's the same species. IE: a dog is of the same species as a dog, regardless of breed. In short, you can breed a dog with another dog of any breed, and the offspring will be able to produce offspring.
His definition of genus would be one step removed from that - if the genetic similarity is close enough to produce offspring, but not viable offspring - IE: a mule or the end result of mating a dog with a coyote. You get offspring, but they can't further reproduce.
I agree with you that it really is a more abstract distinction, I just thought that his definition seemed logical.
Species is, in practice, also arbitrary. It is not unheard of for subspecies A & B to interbreed, subspecies B & C to interbreed, but A & C to be unable to interbreed. This fuzziness is consistant with, and predicted by, neo-darwinism. Otherwise, multiple members of a new species would have to spontaneously appear in the same generation or die without reproducing.