http://www.wired.com/news/technology/0,70924-0.html?tw=wn_technology_5

You Can Make a Monkey Out of Me

Associated Press 10:00 AM May, 18, 2006

Humans and chimps diverged from a single ancestral population through a complex process that took 4 million years, according to a new study comparing DNA from the two species.

By analyzing about 800 times more DNA than previous studies of the human-chimp split, researchers from the Broad Institute of MIT and Harvard were able to learn not just when, but a little bit about how the sister species arose.

"For the first time we're able to see the details written out in the DNA," said Eric Lander, founding director of the Broad Institute. "What they tell us at the least is that the human-chimp speciation was very unusual."

The researchers hypothesize that an ancestral ape species split into two isolated populations about 10 million years ago, then got back together after a few thousand millennia. At that time the two groups, though somewhat genetically different, would have mated to form a third, hybrid population. That population could have interbred with one or both of its parent populations. Then, at some point after 6.3 million years ago, two distinct lines arose.

Some experts in human evolution are skeptical of that precise scenario, but nevertheless impressed with the study.

"It's a totally cool and extremely clever analysis," said Daniel Lieberman, a professor of biological anthropology at Harvard. "My problem is imagining what it would be like to have a bipedal hominid and a chimpanzee viewing each other as appropriate mates, not to put it too crudely."

Past studies that compared human and chimp DNA could only offer a point estimate of how long ago the two species split by averaging the amount of divergence in their genes. Generally, those studies come up with a figure of about 7 million years ago.

But since the completion of the chimpanzee genome project in September it is possible to look at how specific sections of the genetic code have evolved. The Broad Institute study, which will be published in a future issue of the journal Nature, is one of the first to do that.

"There are a lot of big surprises here," Lander said.

For one thing, the new data suggest the human-chimp split was much closer to the present than the 7 million year date that fossils and previous studies indicate — certainly no earlier than 6.3 million years ago, and more likely in the neighborhood of 5.4 million.

The data also show that the human-chimp split probably took millions of years. That's because in some parts of the DNA sequence the genetic difference between humans and chimps is so large that those genes must have been isolated from each other nearly 10 million years ago. But in other places the human and chimp lines are so close that they appear to have still been swapping genetic material at least until 6.3 million years ago.

One of those areas is the X-chromosome, which is intriguing.

"The genes that are a barrier to speciation tend to be on the X-chromosome," said David Reich, the main author of the study.

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There are three basic types, Mr. Pizer, the wills, the won'ts, and the can'ts. The wills accomplish everything, the won'ts oppose everything, and the can'ts won't try anything.

For one thing, the new data suggest the human-chimp split was much closer to the present than the 7 million year date that fossils and previous studies indicate — certainly no earlier than 6.3 million years ago, and more likely in the neighborhood of 5.4 million.

When will the next study come along and change everything? Next week, next month, next year?

I'm not knocking science, but we all know todays 'new data' is tomorrows 'old data'... ;)

For one thing, the new data suggest the human-chimp split was much closer to the present than the 7 million year date that fossils and previous studies indicate — certainly no earlier than 6.3 million years ago, and more likely in the neighborhood of 5.4 million.

When will the next study come along and change everything? Next week, next month, next year?

I'm not knocking science, but we all know todays 'new data' is tomorrows 'old data'... ;)

Yes.... this is known as progress.

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Belief gets in the way of learning

For one thing, the new data suggest the human-chimp split was much closer to the present than the 7 million year date that fossils and previous studies indicate — certainly no earlier than 6.3 million years ago, and more likely in the neighborhood of 5.4 million.

When will the next study come along and change everything? Next week, next month, next year?

I'm not knocking science, but we all know todays 'new data' is tomorrows 'old data'... ;)

Jeffrey, you reject evolution outright and uphold the quran. Since the quran is reported by you to us repeatedly as the utmost standard of truth, none of the questions you pose to science will be satisfactory. Honesty demands you desist from continuing to ask for more.

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Founder of BOINC team Objectivists. Oh the humanity! Rational people crunching data!
I did NOT authorize this belly writing!

Jeffrey, you reject evolution outright and uphold the quran. Since the quran is reported by you to us repeatedly as the utmost standard of truth, none of the questions you pose to science will be satisfactory. Honesty demands you desist from continuing to ask for more.

Ya - I haven't heard a peep lately about "Oasis in Space" when I told him that if he couldn't find it at the library, then he could buy one for $1.99!! The textbook is hundreds of pages! For $1.99!!! Who wouldn't jump at it?!
What's that? Religious zealots? Ya, I see your point....

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Never Forget a Friend. Or an Enemy.

Yes.... this is known as progress.

Nothing wrong with progress...

As long as we don't call something fact, when in fact, it really isn't a fact at all... ;)

Yes.... this is known as progress.

Nothing wrong with progress...

As long as we don't call something fact, when in fact, it really isn't a fact at all... ;)

I think you'll find tht 99% of the time the people who actually do the work given field will never use the word fact. Its usually the media who add that inacurate tag. We generally say "our current understanding is..." or "current information would suggest...". Researchers who claim definite answers are the ones who don't get published.

Robert

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As long as we don't call something fact, when in fact, it really isn't a fact at all... ;)

Oh man, the irony is almost fatal....

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Never Forget a Friend. Or an Enemy.

Jeffrey said:

When will the next study come along and change everything? Next week, next month, next year?

I'm not knocking science, but we all know todays 'new data' is tomorrows 'old data'... ;)

It's extremely rare that a new study changes everything. Even Darwin's theory of evolution didn't change everything, the concept of evolution was around long before. He just refined the mechanism.

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