Chimps Belong in Human Genus? 928
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.
Bogus (Score:5, Insightful)
We've only fully mapped the human genome so far. I bet if we fully mapped the chimp genome, we'd see many many more entries in the diff log than we thought.
It's about time... (Score:2, Insightful)
Are you mostly a chimp? Okay, but not me. (Score:2, Insightful)
If you want to believe that you are almost a chimpanzee, that's fine, but I'm not believing. Note that the researchers ignored DNA that is not expressive. That may be a sensible idea, or it may be that the ignored DNA expresses itself in a way that has not been discovered.
Classification System Stinks (Score:5, Insightful)
Our current system for categorizing the inhabitants of this is long outdated and is based largely on phsycal characteristics of the components on the creature, rather than the stuff it is actually made up of.
We find we've had to tweak this existing system to make new species fit. We've even had to add new kindoms! Many species bridge, these categories making them all the more harder to classify.
A better, more accurate, system needs to be devised based on current technologies that classify based on genetic code. The point of a classification system would be to allow us to draw similarities in creatures while studying them based on available data for ones in the same category. A genetic model would be very beneficial for this very reason.
IMHO.
Antropomorphic principle (Score:5, Insightful)
The Antropomorphic principle is the name given by a tendency by us humans to believe that our situation is unique. It goes from believing in our divine origin, to the earth is the centre of the universe (Ptolomeic) to the sun is the centre of the universe (Copernicus), to the current incantation of the big bang (Gamow) with an ever expanding universe.
Placing humans in their own genus seems to fit right along those lines. We are unique, and no other animal deserves to be even close to us...
Someone had to say it... (Score:5, Insightful)
I'm sure the creationists will pitch a fit if chimps are reclassified. I wonder if there would be any legal ramifications regarding the rights of chimps compared to other animals.
Re:Are you mostly a chimp? Okay, but not me. (Score:1, Insightful)
Re:But isn't the real test... (Score:5, Insightful)
Re:Antropomorphic principle (Score:3, Insightful)
Sumner
Re:Are you mostly a chimp? Okay, but not me. (Score:4, Insightful)
So there is no big deal, when some scientist determines humans are mostly chimps. All that s/he says is that the distance between human and chimp species is less than we thought. And mind you, statistically, there was a 50% chance that this study would have said this!
Re:People don't realize.... (Score:2, Insightful)
Yes, and which of us still defecates in his own nest? Evolution is a point of view; it really has nothing to do with how 'advanced' a species is. That term, advanced, is used in reference to our own subjective advancement, and shouldn't be a factor in scientific classification.
If you want to be subjective in your classifications, humans should be seperately classified from chimps, but only because we have more in common (socially) with rats and vermin.
Re:Antropomorphic principle No it's not (Score:3, Insightful)
Take this with a handful of salt (Score:5, Insightful)
Re:Classification System Stinks (Score:5, Insightful)
There's another problem with this though if you want to go strictly genetics for your classification, paleontology.
The vast majority of work done by paleontologists simply cannot use genetics. They are almost completely stuck using comparative physical characteristics. I'm sure that they'll get some things wrong, as far as relations, but like I said, they're mildly stuck.
If you can come up with a unified classification system that satisifies both the paleontology and the genetics crowds, then you might just have more than a few papers and a PhD thesis there...;)
Re: Bogus (Score:5, Insightful)
> We've only fully mapped the human genome so far. I bet if we fully mapped the chimp genome, we'd see many many more entries in the diff log than we thought.
However, the real reason for the bogosity of the claim is that clades aren't defined by thresholds in DNA differences. The tree of common descent is there, but it's somewhat arbitrary how far up from a leaf you go before you reach a node that you call "species", "genus", etc. They are merely labels of convenience, and if we suddenly do or don't find it convenient to put the chimps in the genus Homo it doesn't really tell us anything we didn't already know about the relationships in that branch of the tree. (I have a physical anthropology textbook published ten years ago that already mapped out this branch of the tree according to our current understanding of it, then already based on DNA comparisons as well.)
The real news from this is that by focusing on "functionally important" genes we now know that our "functionally important similarity" is 99.4% rather than the 97.whatever% that we previously got when looking at genes in general.
Mod Parent Up!! (Score:1, Insightful)
Re:They're definitely in the same genus as... (Score:3, Insightful)
WHAT?!?!?! You have much better drugs than I. The conservatives would want the exact OPPOSITE. If chimps were found to be 99.999% the same as humans, the Religious right would be all over it saying it ain't so, because only humans can go to heaven.
problem with Dawkins visual (Score:4, Insightful)
Hrm. Now to me, this sounds likely to perpetuate the "we came from chimpanzees" style of (mis)interpretation not the idea that "we share a common ancestor with chimpanzees". So, to correct that...is the chain 155 miles long, with the common ancestor at 77.5 miles, and than it starts going daughter daughter daughter instead of mother mother mother, or is the 155 to the common ancestor, and then chimps are like 310 miles away instead?
I guess it would be useful to know what the assumptions are for generation length and armspan...
Re:People don't realize.... (Score:3, Insightful)
Uhm, for that matter every single species on the planet has had just as much time to evolve. That is, if you believe in a single common ancestor, which most evolutionary biologists do. Certainly for multicellular organisms, there's somewhere back there a single common ancestor.
Let's put every species in our genus!
Why not put them in the same Genus as us?
Cuz Linnaean taxonomy is an artificial human convention imposed on the world. It's not up to the world to divide itself neatly into kingdom, phyllum, class, order, family, genus, and species. And while most modern taxonomy is debated based on genetic distance, things don't divide up neatly into those slots.
The debate is a pedantic one that has no bearing on how the world works, or really, on our understanding of it.
oh? just scientists? (Score:5, Insightful)
the literary community,
the artistic community,
the philosophical community,
the musical community,
the educational community,
the list goes on...
You shall know them by their works.
Re:Dumb (Score:5, Insightful)
Re:People don't realize.... (Score:2, Insightful)
The problem with that system is how much alike do two creatures have to be in order to be in the same family? If you're not specific enough, you might end up placing hummingbirds and flies in the same family because they both have superb control over their flight characteristics, and they both like sugarwater.
If you're too specific, you'll start separating (as an example from history) people of African descent from people of European descent.
Classifying species based on genotype allows us to trace nature's evolutionary path, and understand biological history accordingly.
Re:It's about time... (Score:5, Insightful)
It's amazing to me that this comment was modded "Insightful". Chimps have had 4-7 million years since we split from a common ancestor (according to the article) and they're still swinging in trees. Humans are reaching for the stars.
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.
As long as we're making bets... (Score:3, Insightful)
I bet religious lunatics like you are responsible for the greatest attrocities ever perpetrated by human beings, smiling and whistling hymns all the while.
I bet that if homo sapiens ever evolves away from religious hocus-pocus voodoo nonsense, the world will be a better place for everyone.
I bet if people were taught that the "theory of evolution" was as scientifically established as the "theory of gravity", there wouldn't be as much refusal to even accept the possibility that it just might be true.
I bet I misinterpreted your post. I bet I went way overboard. I bet I should've posted AC...
Re:It's about time... (Score:3, Insightful)
All of them do, given their ability to sense their surroundings.
> What animal can split the atom?
The sun splits atoms all the time. You don't have to be an animal to do that!
> What animal is loved by God?
I recall a passage in the old testament about how God tried to force the Egyptians to adopt frogs and grasshoppers...so it's gotta be them!
> What animal can build an engine?
Funny, I know millions of humans can't build engines either. But I have seen hamster powered bicycles!
> What animal can love?
Ever seen elephants visit the graves of their loved ones year after year? Ever own a dog?
> What animal can speak?
Quite a few parrots and other bird species are quite capable of speech. Remember that parrot that can speak the names of objects or name an action?
> What animal can appreciate beauty?
Peahens lusting after the prettiest peacocks.
There is a cool species of birds that builds multi-story birdsnests to impress the female birds of the same species. Complete with porch entrances, awnings, the whole works! The best house-builders get the most bird tail.
> What animal can write poetry?
Chimpanzee sign language could be considered poetry. It's probably better than the post-modern crap published in recent years.
> What animal other than man is the utter pinnacle of all creation?
Toxoplasma Gondii...it's the master of humans AND cats! It's the coolest parasite out there...
You forgot a few other questions:
What animal practices altruism?
Vampire bats.
As others have noted... (Score:5, Insightful)
Since then, other systems have evolved, and have been tagged on. In consequence, the current "system" is really a complete mish-mash of differing systems, with no real agreement on what system applies under what circumstance.
To those who advocate DNA-based classification, I'd argue that that only works on still-living species. If we don't have the DNA, we can't do that. So, we'd end up using some other system for those, anyway, which means we'd still be using a hybrid.
The argument that chimps belong to the "homo" group seems valid enough. We're not talking about direct ancestors, but about a common ancestor who is already established as a part of the "homo" group. (Percent then becomes irrelevent. Once you can establish that common ancestor, and establish that said ancestor is already classed as being in the "homo" genus, the rest becomes moot.)
The only rational argument I can see against it is if it can be established that the chimp branch has diverged in some critical way that, even though the divergence is small, would still place it in a different genus. You'd probably want to alter the genus to the verb, rather than the noun, in this case, to show the relationship while acknowledging the difference.
A rose by any other name... (Score:1, Insightful)
What we, the inventor and sole user of the classification system, decide at any point what falls in which category adds nought to the truth of a particular theory, but it goes a long way toward swaying those of no particular interest, and also those with a vested interest, to the ideas of those who make the classification.
Just my 2p.
genes (Score:1, Insightful)
Of course, the chrimbos are going to be annoyed about this. They're generally offended by any suggestion that human beings are descended from the same ancestors as other animals, and particularly sensitive about being reminded that superstitious / religious behaviour doesn't put us that far above pigeons [yorku.ca].
If we had that much in common with chimps (Score:2, Insightful)
Re:if { chimps == homosapiens } .... (Score:3, Insightful)
Re:Bogus (Score:3, Insightful)
Re:Bogus (Score:5, Insightful)
Human-Chimp: 1.45
Human-Gorila: 1.51
Human-Orangutang: 2.98
Gorilla-Chimp: 1.57
Standard errors on these numbers are about 0.2, so the human/chimp/gorilla differences are not statistically significant. The evidence is growing that the human/chimp split is more recent than the gorilla split, but as far as I know this hasn't yet been determined beyond reasonable doubt.
The numbers in the article are only looking at DNA nucliotides in genes, which change much more slowly then the bulk of DNA which is 'junk'. This is because inside a gene, most mutations will be disadvantageous and selected against. The numbers I give above are from non-coding DNA.
Note that even within genes, not all nucleotide substitutions have any evolutionary effect. There are 4 nucleotides (think letters) which come in groups of 3 (codons, think words) giving 64 possible codons to code for 20 amino acids (plus a little punctuation) so most amino acids have several codons that code for them. Therefore even inside a gene, some nucleotide substitutions will be 'synonymous' - they will not change the protien generated from the gene.
For the purpose of saying "How different (functionally) are we from chimpanzees", it makes most sense to look at how different the proteins are - non-coding DNA and synonymous changes within coding DNA have no effect on phenotype (the critter that the DNA builds.)
For the purpose of timing evolutionary branchings, it makes most sense to look at non-coding DNA and synonymous substitutions. This is because the rate at which substitutions/mutations occur at these sites is much less variable than at coding sites. At coding sites, the rate is constrained by evolutionary pressures, and those pressures may not be the same on different lineages.
Anyway, the story looks like a big yawn to me - this isn't anything we haven't known about for years. There's probably lots of interesting stuff in the details, but not the '99.4%' number. Saying this means were in the same genus is pure sensationalism - the concept of genus is more fuzzy than species, and is fairly arbitrary. There is a fair argument that homo and pan are separate genii(?) only because of parochialism, but this data is not a strong reason to change it.
* I'm studying up for my new job in molecular phylogentics. It will be something of a challenge, given that my degrees are in physics and astronomy.
** Book is Molecular Evolution, Li, 1997. Data is from Li et al 1987.
So What? We share 93% of our genes with Field Mice (Score:3, Insightful)
Re:It's about time... (Score:2, Insightful)
Yes, you, the previous poster, and all posters in between are 'ridiculously' and 'obviously' more intelligent than 'just another monkey' *sic*
But there are many hundreds of qualities possesed by Chimps and other species on this planet that we drastically lack.
Don't you find it a bit peculiar that the qualities that you judge to be obviously more important than all others just happen to be the ones you posses?
Re: Bogus (Score:5, Insightful)
Incidentally, this is one reason why creationist blather about speciation is a load of bull - there isn't really a strict definition for speciation on the molecular level. It's a series of events that are well documented, but there isn't one point where you suddenly get a new species. Creationists talk about speciation as if there's a sudden "promotion" or massive change that has to occur, but that really has no basis in reality. Speciation is simply the sum of reproductive isolation and mutation/genetic drift.
Re: It's about time... (Score:3, Insightful)
I once read a description in a science fiction novel that I particularly like. The analogy was made between intelligence and heating water. Below the boiling point, water is just water and can be compared to other bits of water in a fairly nice linear fashion according to temperature. But as the water hits the boiling point, interesting things begin to happen that make it altogether different. Sure, you can continue to compare the boiling water to cooler water according to the common measure of temperature, but the really important differences now lie elsewhere. Temperature becomes only one small part of a whole host of interesting differences.
Yes, this analogy breaks down in a whole bunch of ways, but the central idea is that finding only a tiny difference between human and animal means we just aren't measuring the right thing. And even if we found some common measure, humans have passed a nonlinear threshold across which comparisons don't hold much meaning.
As for who is the fair arbitrator of excellence, exactly whose other opinion are you going to compare with? Yes, both humans and chimps get wet in the water, we both require oxygen, we both ingest plant and animal matter for fuel, we both crap in the woods. But I still maintain that the more interesting factors are the differences, for that's where we will find clues to what makes us human.
"functionally important DNA" == useless study (Score:3, Insightful)
Leaving aside whether they include mitochondrial DNA and other non-coding and yet genetically important chemical units such as the free transposons and stuff floating around, the phrase "functionally important DNA" means that these guys have made a subjective decision about which DNA is important. Given that we know that we don't know for sure which DNA truly is junk and which is useful, that was a fairly stupid thing to do, and essentially renders the work useless.
"Junk" DNA has also been used to track similarities between species (because at least in theory it mutates at a similar rate to "useful" DNA) and the most obvious and reliable conclusion that has resulted is "molecular clocks are useless".
Re:It's about time... (Score:3, Insightful)
But there are many hundreds of qualities possesed by Chimps and other species on this planet that we drastically lack.
Don't you find it a bit peculiar that the qualities that you judge to be obviously more important than all others just happen to be the ones you posses?
Tell you what: you go off and discuss it with a chimp who can debate the point and let us know what you come up with.
It's all in the software (Score:2, Insightful)
It's all in the software.