New fossil findings put evolution in question

[Sonic Youth]

Then I'm really sorry about that.

But to clear up the matter of the APs headline, it says "old evolution theory", meaning a subset theory within the overall concept of evolution, the Anagenesis theory. It doesn't mean the entire Evolution school of thought is now in jeopardy.

[MovieWes]

I'm not a creationist. Sorry if the title of this thread was misleading, but it wasn't my intention to write a misleading headline. I don't have an agenda; I was just posting an article that I found interesting. Sorry if my wording offended you.

And my headline in no way implied that these findings debunk evolution; all I wrote is that it was called into question, which is pretty much what the original headline said anyway (I believe the exact word the author used was "challenge"). You can interpret the meaning anyway you want, but I hope that my credibility isn't damaged too much.

[Sonic Youth]

And if I come across as too harsh, sorry. But I have my one major prejudice. I tolerate all races, all religions, even Republicans. (Just not the ones who lie.) But Creationists are where I draw the line for good manners.

And please, no one direct me to any "scientific" literature. The last time that happened, I was recommended an article by some guy who claimed dinosaurs and humans co-existed, and his proof were a couple of cave paintings in France that no one else has verified.

[Sonic Youth]

Moviewes, it would have done wonders for your credibility if you didn't write a headline that's inaccurate.

Nothing in this finding or in this article puts evolution in question at all. Not even the HEADLINE says evolution is in question. All it puts into question is the school of thought called Anagenesis (which is the basis for that evolution cartoon that the article references), and that has been challenged and debunked piecemeal by evolutionary scientists for years now. The concept of two contemporaneous ancestral species is old news, baby. We've already found plenty of fossils of both species. All that's new is the location that these fossils were found.

And if Creationists are going to say this debunks Evolutionary theory, then they're even dumber than they let on. Any careful reading of these news stories should make it self-evident (or so one would think) that this has NOTHING to do with the origins of modern Homo Sapiens. It has to do with the relationship between two early human species. But some people would rather risk the flames of hell by breaking the commandment regarding lying in order to save the planet's souls.

Sheesh, the lengths some people will jump...

[MovieWes]

Fossils challenge old evoluton theory

By SETH BORENSTEIN, AP Science Writer
Wed Aug 8, 5:57 PM ET


WASHINGTON - Surprising research based on two African fossils suggests our family tree is more like a wayward bush with stubby branches, challenging what had been common thinking on how early humans evolved.

The discovery by Meave Leakey, a member of a famous family of paleontologists, shows that two species of early human ancestors lived at the same time in Kenya. That pokes holes in the chief theory of man's early evolution — that one of those species evolved from the other.

And it further discredits that iconic illustration of human evolution that begins with a knuckle-dragging ape and ends with a briefcase-carrying man.

The old theory is that the first and oldest species in our family tree, Homo habilis, evolved into Homo erectus, which then became human, Homo sapiens. But Leakey's find suggests those two earlier species lived side-by-side about 1.5 million years ago in parts of Kenya for at least half a million years. She and her research colleagues report the discovery in a paper published in Thursday's journal Nature.

The paper is based on fossilized bones found in 2000. The complete skull of Homo erectus was found within walking distance of an upper jaw of Homo habilis, and both dated from the same general time period. That makes it unlikely that Homo erectus evolved from Homo habilis, researchers said.

It's the equivalent of finding that your grandmother and great-grandmother were sisters rather than mother-daughter, said study co-author Fred Spoor, a professor of evolutionary anatomy at the University College in London.

The two species lived near each other, but probably didn't interact, each having its own "ecological niche," Spoor said. Homo habilis was likely more vegetarian while Homo erectus ate some meat, he said. Like chimps and apes, "they'd just avoid each other, they don't feel comfortable in each other's company," he said.

There remains some still-undiscovered common ancestor that probably lived 2 million to 3 million years ago, a time that has not left much fossil record, Spoor said.

Overall what it paints for human evolution is a "chaotic kind of looking evolutionary tree rather than this heroic march that you see with the cartoons of an early ancestor evolving into some intermediate and eventually unto us," Spoor said in a phone interview from a field office of the Koobi Fora Research Project in northern Kenya.

That old evolutionary cartoon, while popular with the general public, is just too simple and keeps getting revised, said Bill Kimbel, who praised the latest findings. He is science director of the Institute of Human Origins at Arizona State University and wasn't part of the Leakey team.

"The more we know, the more complex the story gets," he said. Scientists used to think Homo sapiens evolved from Neanderthals, he said. But now we know that both species lived during the same time period and that we did not come from Neanderthals.

Now a similar discovery applies further back in time.

Susan Anton, a New York University anthropologist and co-author of the Leakey work, said she expects anti-evolution proponents to seize on the new research, but said it would be a mistake to try to use the new work to show flaws in evolution theory.

"This is not questioning the idea at all of evolution; it is refining some of the specific points," Anton said. "This is a great example of what science does and religion doesn't do. It's a continous self-testing process."

For the past few years there has been growing doubt and debate about whether Homo habilis evolved into Homo erectus. One of the major proponents of the more linear, or ladder-like evolution that this evidence weakens, called Leakey's findings important, but he wasn't ready to concede defeat.

Dr. Bernard Wood, a surgeon-turned-professor of human origins at George Washington University, said in an e-mail Wednesday that "this is only a skirmish in the protracted 'war' between the people who like a bushy interpretation and those who like a more ladder-like interpretation of early human evolution."

Leakey's team spent seven years analyzing the fossils before announcing it was time to redraw the family tree — and rethink other ideas about human evolutionary history. That's especially true of most immediate ancestor, Homo erectus.

Because the Homo erectus skull Leakey recovered was much smaller than others, scientists had to first prove that it was erectus and not another species nor a genetic freak. The jaw, probably from an 18- or 19-year-old female, was adult and showed no signs of malformation or genetic mutations, Spoor said. The scientists also know it isn't Homo habilis from several distinct features on the jaw.

That caused researchers to re-examine the 30 other erectus skulls they have and the dozens of partial fossils. They realized that the females of that species are much smaller than the males — something different from modern man, but similar to other animals, said Anton. Scientists hadn't looked carefully enough before to see that there was a distinct difference in males and females.

Difference in size between males and females seem to be related to monogamy, the researchers said. Primates that have same-sized males and females, such as gibbons, tend to be more monogamous. Species that are not monogamous, such as gorillas and baboons, have much bigger males.

This suggests that our ancestor Homo erectus reproduced with multiple partners.

The Homo habilis jaw was dated at 1.44 million years ago. That is the youngest ever found from a species that scientists originally figured died off somewhere between 1.7 and 2 million years ago, Spoor said. It enabled scientists to say that Homo erectus and Homo habilis lived at the same time.