Joined: Sat Oct 16, 2004 10:53 pm Posts: 20537 Location: The City Of Trees
No shit, that was the headline on Yahoo's front page. Wouldn't a more accurate way to put it be, "One fact underneath the broad evolution theory challenged"?
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.
Joined: Sun Oct 17, 2004 12:47 am Posts: 46000 Location: Reasonville
very interesting. i had it on the site yesterday and played it more like 'is it time to rethink evolution?' and i can see where you'd disagree with that as a whole ... but on a lower scale, it does challenge a major part of our evolution, so...
_________________ No matter how dark the storm gets overhead They say someone's watching from the calm at the edge What about us when we're down here in it? We gotta watch our backs
Joined: Sun Oct 17, 2004 1:14 am Posts: 37778 Location: OmaGOD!!! Gender: Male
This isn't really a new idea.
Maybe there is specific evidence of two specific sub species living simultaneously when there had previously not been that evidence, but I don't think any but the most simple-minded evolutonary biologist or anthropologist thought that human evolution (or any evolution for that matter) is a straight line.
If you look at evolution backwards (from now towards the past), our lineage appears to be a straight line, but if you look at at it forwards, there are always many branches into a "bush" type pattern, as the article describes.
Just look at your own family tree. You have your two parents, your four grandparents, your eight great-grandparents, etc... It's all very linear, and it appears inevitable that it would all lead to you. To paraphrase the wisdom of Butthead, "Our dads had sex, and their dads had sex, so you know what that means? It means that WE will have sex!"
The reality is better seen if you don't "prune" the tree to show only your lineal ancestors, but also all of your parents' siblings and their descendants, and your grandparents' siblings and their descendants, etc... But then imagine that none of your cousins end up reproducing. Several generations down the line, you may still be remembered, but it would be as if all of those cousins never existed.
That's the way simple thinkers see evolution. A person in the past must have been your great great-grandparent, and the idea that they were some distant cousin doesn't even enter their mind. It's exactly the same "logic" that spews out such wisdom as, "If we evolved from monkeys, then how come there are still monkeys?"
Hmmm, yeah...
_________________ Unfortunately, at the Dawning of the Age of Aquarius, the Flower Children jerked off and went back to sleep.
Joined: Mon Oct 18, 2004 2:29 pm Posts: 6217 Location: Evil Bunny Land
[quote="psychobain"]i just discovered that the coccyx is the remnant of a lost tail, and that every embryo has a tail[/quote
That's not true.
The coccyx is an important point for muscle attachment. These muscles are used for balance, standing upright, and pooping. Fetuses don't really have tails. That is the precurser to their coccyx. Muscles and limbs wont develop until stimulated by the spine, at which time the legs will develop and the coccyx will be inside the body.
_________________ “Some things have got to be believed to be seen.”
- Ralph Hodgson
Joined: Mon Oct 18, 2004 2:29 pm Posts: 6217 Location: Evil Bunny Land
psychobain wrote:
well, can be true, but i bet that theres people that doesnt agree
ps: if you're some fanatic, tell me next time
No. I believe in evolution 100%.
That coccyx/tail myth is just bullshit that people spread around as evidence of evolution. Anyone with a basic knowledge of human anatomy can tell you that the coccyx doesn't have anything to do with a tail.
There is plenty of good evidence for evolution without spreading nonsense.
_________________ “Some things have got to be believed to be seen.”
- Ralph Hodgson
Joined: Thu Dec 16, 2004 1:54 am Posts: 7189 Location: CA
Gimme Some Skin wrote:
psychobain wrote:
well, can be true, but i bet that theres people that doesnt agree
ps: if you're some fanatic, tell me next time
No. I believe in evolution 100%.
That coccyx/tail myth is just bullshit that people spread around as evidence of evolution. Anyone with a basic knowledge of human anatomy can tell you that the coccyx doesn't have anything to do with a tail.
There is plenty of good evidence for evolution without spreading nonsense.
The Catholic church is supposedly down with evolution, but someone was telling me that the current Pope isn't so hot on it. Is this accurate or no?
And yes, Evolution is a fad that people are "hot for", not a scientifically grounded theory.
Joined: Mon Oct 18, 2004 2:29 pm Posts: 6217 Location: Evil Bunny Land
simple schoolboy wrote:
Gimme Some Skin wrote:
psychobain wrote:
well, can be true, but i bet that theres people that doesnt agree
ps: if you're some fanatic, tell me next time
No. I believe in evolution 100%.
That coccyx/tail myth is just bullshit that people spread around as evidence of evolution. Anyone with a basic knowledge of human anatomy can tell you that the coccyx doesn't have anything to do with a tail.
There is plenty of good evidence for evolution without spreading nonsense.
The Catholic church is supposedly down with evolution, but someone was telling me that the current Pope isn't so hot on it. Is this accurate or no?
And yes, Evolution is a fad that people are "hot for", not a scientifically grounded theory.
No. That's not right.
The current Pope recently made a statement about how big of a mistake it is to NOT accept evidence for evolution. He pissed off a lot of Evangelicals because he said that believing in evolution doesn't mean you don't believe in God. The two aren't mutually exclusive.
Since Evangelicals believe that God went "Poof...Adam...tada!!!", they seem to think what the Pope was saying is crazy talk.
_________________ “Some things have got to be believed to be seen.”
- Ralph Hodgson
Joined: Thu Dec 16, 2004 1:54 am Posts: 7189 Location: CA
Gimme Some Skin wrote:
simple schoolboy wrote:
Gimme Some Skin wrote:
psychobain wrote:
well, can be true, but i bet that theres people that doesnt agree
ps: if you're some fanatic, tell me next time
No. I believe in evolution 100%.
That coccyx/tail myth is just bullshit that people spread around as evidence of evolution. Anyone with a basic knowledge of human anatomy can tell you that the coccyx doesn't have anything to do with a tail.
There is plenty of good evidence for evolution without spreading nonsense.
The Catholic church is supposedly down with evolution, but someone was telling me that the current Pope isn't so hot on it. Is this accurate or no?
And yes, Evolution is a fad that people are "hot for", not a scientifically grounded theory.
No. That's not right.
The current Pope recently made a statement about how big of a mistake it is to NOT accept evidence for evolution. He pissed off a lot of Evangelicals because he said that believing in evolution doesn't mean you don't believe in God. The two aren't mutually exclusive.
Since Evangelicals believe that God went "Poof...Adam...tada!!!", they seem to think what the Pope was saying is crazy talk.
No, it wasn't an evangelical, and I thought the Pope wouldn't part with the recent trend on this one.
I like how so many creationists like to make evolution out to be some sort of competing belief system. As if it were somehow the equivalent of the atheist version of Christianity or something. I don't get it. I understand that they are threatened by it, but its not like its buddhism or something.
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