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Well I'll Be A Monkey's Uncle
killproc writes "A new report suggests that interbreeding between humans and chimpanzees happened a lot more recently than was previously thought. The report, published in the most recent issue of the journal Nature, estimates that final break between the human and chimpanzee species did not come until 6.3 million years ago at the earliest, and probably less than 5.4 million years ago."
"The Nature paper joins a wave of work showing that the lines between species are hazy ..."
This is the critical point that creationists who blather on about "macroevolution vs. microevolution" (a distinction without a difference) and "nobody has ever observed a speciation event" (just not true) willfully miss. Species lines are imposed by observers after the fact; they are not inherent in the nature of living organisms.
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
What this shows is that there was likely interbreeding between the ancestor line of humans and the ancestor line of chimpanzees. Unfortunately, all the headlines I've read skip that distinction and dive right into "humans and chimps interbred." They were not either modern humans or modern champanzees, and were likely much closer in genetics and appearance than we are to modern chimps, even though even now we are very close genetically after 5 million years of divergence.
I think I'll stop here.
That being said, I don't think we descended from chimps. I've made a rather lengthy arguement about this before and I'm not sure I totally want to get into again, but I just don't believe humans came from chimps.
Dude, nobody thinks humans are descended from chimps. Chimps and Humans have a common ancestor (and now the divergence line is a little more blurred).
There are shills on slashdot. Apparently, I'm one of them.
I hate to quibble, but the summary is not quite right. It isn't like there were chimpanzees, humans evolved "up" from chimpanzees, and the chimpanzees remained the same. This isn't how evolution works. What happened was that a single species broke into two separate species. Both species continued to change and evolve. A chimpanzee has done just as much "evolving" as a human has, it just went in a different direction. Whatever the case though, if you were to compare a chimpanzee ancestor to a human and a modern chimp, you would find that you are looking at three very different species.
I am not saying that human evolution isn't teh pwn, but keep in mind that things don't "branch" like in a tree where the original branch remains. When things branch they move off in different directions and the original species before the branch is lost.
You mistake in the way you think about selection.
There is no 'law of evolution' kind of thing that says that a species will involve into something more complex or intelligent.
Natural selection simply works because a certain species is capable to stay in existence.
Sometimes being stupid and just breed is more efficient than being intelligent.
Ants have a complex structure which allows them to spread very efficiently. Knowing how to paint for some reason wasn't needed for them to spread widely and thus such an feature would only result in extra lugage to carry around.
Maybe out species at some point managed to stay alive longer by being a little bit more creative than our cousins. That might have been an factor that resulted in more offspring.
Jeroen
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Abstraction is a strong part of the process used in learning. View a set of data, create an abstract theory. Humans happen to be better at it than most animals.
Art is simply one way of expressing these abstractions. Same thing with God - you see a bunch of seemingly miraculous things happening... something must be acting to cause those miracles. Ergo, God.
As to ants vs. humans, well, ants don't have the same needs we do because all ants are moderately simple. They just don't have the neuron mass to act independently. Nor is it likely for them to evolve the neuron mass, because of structural issues re: exoskeletons.
Athletic Scholarships to universities make as much sense as academic scholarships to sports teams.
Well, as a bioinformaticist who has been following this work for a while (both the first and last authors, along with most of the others present at our weekly group meeting), I'd say that the work isn't sloppy.
It is controversial, as it doesn't match with the fossil record. But if you knew the guys involved (and the internal vetting process at the Broad), you'd understand that this work has gone through massive peer review by some of the most gifted individuals in genetics I've seen.
I'd guess that John Hawks isn't a genetics specialist (Just as David isn't an anthropologist), so when data starts conflicting, it's hard for anyone to give ground. I think it's exciting, because it allows for more experiments to be divised on both ends, and for more clarification to be arrived.
In other words, the scientific process.
Just to agree with you, and add a little bit: in general, science doesn't need to explain the entire story. In fact, science has a long history of concentrating on the things it can explain, and ignoring the things that it cannot. For example, when Newton's law of gravity came out, there was a lot of controversy as to how objects could interact with each other at a distance, about which Newton's law of gravity says nothing. But how can you argue with it? It is so powerful, and so elegant, it must be getting part of the story right, so to speak. It wasn't until 200 years later, with Einstein, that physics had anything interesting to say about how those objects interacted with each other at a distance. Similarly, there seem to be a lot of big, important questions left in the evolution of the human species. It does seem quite little strange to understand evolutionary pressures that allowed us to carry food on the savannas also allowing us to go to the moon, or paint the Mona Lisa. Maybe there is more to the story then. But that doesn't need to mean that the part of the story we do have is wrong.
The point is specialization. Humans, for whatever reason, specialized in tool use as a means for survival. We learned to see the environment as something to be manipulated. Abstract thought became an advantage, so it prospered in our evolution, and we adapted to it. Art is an outgrowth of abstract thought and tool use. Doesn't serve any purpose really, it just happens to be a side-effect of the kind of brain that could produce gunpowder.
Ants, on the other hand, are pretty near perfect. They are utterly dominant in their niche, amazingly successful. The ongoing ant-ian evolution involves coming up with new and exciting ways to be dominant in their niche. Better venom, better reproductive turnaround, better coordination, ability to survive in other environments. The ability to create art is hilariously useless to them. Advanced cognition is hilariously useless. Can you imagine the worker ants going on strick because they don't get enough nectar, or get sent into too many hazardous situations? Any ant that started evolving in that direction would be less fit to live, an evolutionary flop.
Intelligence is not the end-all be-all in evolution. Why are chimps not intelligent artisans like us? Maybe because they climb trees better than we do. Why not? They didn't need to pick up tool use, because they could out-climb all their predators, whereas we had to have a big ass club up in the tree with us because panthers could climb better.
ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
I also happen to think that as we investigate more and more pairs of close species, we will find this is not at all an uncommon pattern. There are lots of hybrids out there in nature, and you can be sure that genes make it across "species boundaries" with some regularity for quite a while.
One final note to destroy my credibility. Is anyone surpised that people had sex with chimps? (Okay, proto-humans with proto-chimps) We are a couple of horny species. I don't know too much about chimp sexual habits, but we humans sure are a kinky bunch to boot.
Most exciting phrase in science: not "Eureka!" but "Hmm... That's funny..." -Asimov (abridged for \. limits)
Ok, well, then the answer is simple: they're lying.
First of all, by all respects, positive mutations in practice DO happen, and indeed one can point to any number of recent examples just in humans, just recently. Tetrachromaticism in women is recent. So is the immunity to the negative effects of LDH cholesterol developed in a single man in Italy (creating descendants among whom heart disease and strokes are vanishingly shockingly rare).
Second of all, think about it logically. Mutation is random. That means that anything it can do, it can undo. So if it can have bad effects, then it can also have good effects (for instance, if one mutation breaks something by changing a T to an A, then the next mutation can change the A back to a T, thus having a positive effect).
Thirdly, creationists generally also admit that mutations can cause observeable variations in a species: longer beaks, shorter legs, etc. But any of these can have positive effects, so they've just unknowingly admitted to something they elsewhere deny.
Finally, talking about mutation and function in this way is itself misinformed. Whether or not a mutation is "beneficial" or not depends a great deal on context. A particular mutation can have a negative effect in one context, and a positive effect in another one. There are certainly mutations that very clearly are better or worse than what came before in all contexts, but by and large there is no objective measure of whether a mutation is beneficial, neutral, or positive. It all depends on a lot of other factors and how it plays out.