Source: [url]http://lightyears.blogs.cnn.com/2011/09/08/ancient-fossils-question-human-family-tree/?on.cnn=3[/url]
[quote]
At a family reunion of the direct evolutionary predecessors of our species, there would be a lot of arguing over whether Australopithecus sediba gets in the door.
Australopithecus sediba is the name of an ancient species discovered in South Africa in 2008. Researchers now have substantial evidence, published in this week's edition of the journal Science, that Australopithecus sediba could be a direct ancestor of the Homo genus, of which humans are a part (we are Homo sapiens). If that's true, it means our family tree may have to be redrawn, with Australopithecus sediba at the stem of the Homo line.
But that's just one possibility, and a controversial one at that.
Researchers studied two partial skeletons, a young male named Karabo and an adult female who has not yet been named, which were found in the remains of a collapsed cave. "Australopithecus" means "southern ape," and "sediba" is "natural spring" or "fountain" in the Sotho language. The team announced the discovery of the previously unknown species in 2010.
'Lucy' discoverer: Why I study human evolution
Scientists have several theories about what these skeletons might mean for human evolution.
The earliest undisputed Homo genus member is Homo erectus, which researchers estimate to be about 200,000 years younger than Australopithecus sediba, so Homo erectus could theoretically be the direct evolutionary descendant. Alternatively, Australopithecus sediba could be the direct ancestor of Homo habilus, considered to be a toolmaker because its hand bones were found next to stone tools, or of Homo rudolfensis, a contemporary of Homo habilus of disputed evolutionary origin. Australopithecus sediba could be related to both of them, and perhaps their current labels are inaccurate. Or, of course, it could be a dead end, although researchers say the skeletons' human-like features suggest otherwise.
Species as experiments in evolution
It makes sense that there seem to have been many variations in anatomical form evolving around 2 million years ago, said Lee Berger, paleoanthropologist at the University of the Witwatersrand in Johannesburg, South Africa, who led the discovery of the fossils.
"As you’re beginning to have the stresses and stressors of environmental change and the things going on in Africa around 2 million years (ago), you would think that many experiments would emerge, Sediba just being one of those," he said.
There can be only one species that gave rise to Homo erectus, which is our direct ancestor, however. To demonstrate stronger evidence, Berger said, archaeologists would have to find fossils that come before and after Australopithecus sediba in the evolutionary lineage.
Based on the variety of Australopithecus forms that have been found, Ian Tattersall, paleoanthropologist and curator at the American Museum of Natural History in New York, who wasn't involved in the study, said he believes Australopithecus sediba probably did not give rise to Homo. Instead, it represents the context in which our true ancestor, in whatever form it was, did arise: during a time when there were many different forms of upright creatures. About 2.6 million years ago there was a huge change in the African fauna, with more grasslands arising; these kinds of environmental factors probably shaped the evolution of different species.
"In some population, some genetic novelty became established which basically set the patent for the genus Homo in a short period of time," Tattersall said. "What we’re not going to see, I think, is the gradual modification over millions of years of an Australopith into Homo."
Exploring the skeletons
Based on the two skeletons studied so far, Australopithecus sediba represents a curious, unique combination of human-like and primitive features.
For instance, consider the brain: Australopithecus sediba's skull shows a cranial capacity of 420 cubic centimeters, whereas a chimpanzee's is about 380 cubic centimeters. Homo erectus is about 200,000 years younger than Australopithecus sediba, and its cranial capacity would be a whopping 900 cubic centimeters. If Australopithecus sediba is the direct evolutionary ancestor of Homo erectus, it suggests a more rapid expansion of brain size over the course of evolutionary history than previously believed. Also, the overall shape of the brain appears to resemble a human's more than a chimp's.
Then there's the matter of feet. Australopithecus sediba has a mostly human-like ankle joint, but the heel bone is mostly ape-like. That's surprising because the species of Lucy, the famous 3-million-year-old skeleton classified as Australopithecus afarensis, has a more advanced heel than Australopithecus sediba. If Berger's skeletons descend evolutionarily from Lucy's species, that would mean that heel anatomy would have evolved from advanced to primitive to advanced again - which is unlikely. Alternatively, Lucy's species may be more of a cousin to Australopithecus sediba, and to our genus, on the evolutionary tree, rather than an immediate relative.
"If that's the case, then there may very well be a ghost lineage," Berger said. In other words, there are probably more fossils out there to explain where these species came from.
At the same time, Australopithecus sediba's pelvis is the most human-like of any found in the Australopithecus genus, Berger said. While females of Lucy's species have wide, stable platforms with a birth outlet, the human pelvis is more bowl-like and curves around the body, and Australopithecus sediba's pelvis is closer to that.
Researchers have good evidence from the hands and feet that Australopithecus sediba was spending a decent amount of time climbing in trees. And the hands, which have grasping capabilities, are more advanced than those of Homo habilus, suggesting it, too, was an early tool-user.
"Sediba and the other early bipedal apes were creatures of relatively small stature that retained a lot of climbing features, particularly in their upper body skeleton, so they spent a lot of time in the trees even though, when they came to the ground, they walked on two legs," Tattersall said.
What led to the deaths of these possible proto-humans that Berger's team studied? They appear to have fallen, perhaps while looking for water, Berger said. But further investigation will reveal more precise details.
From the other evidence that hasn't yet been unearthed or examined, Berger promised his team will also likely discover the dietary habits of Australopithecus sediba and whether they were hairy. Researchers may already have found evidence of soft tissue. And they've got more skeletons to explore from the same area.
"What makes this really exciting is that this is opening this whole question of where the genus Homo came from to re-examination. What they have is a wonderful sample of individuals, of a kind that we don’t really expect to find in the human fossil record. Just one complete skeleton is rare, let alone a whole bunch of individuals," Tattersall said.[/quote]
Nifty.
That's fantastic that they've found so many fossilized skeletons.
It really makes one aware of how much we don't really know about our evolutionary history.
It's an exciting time to be alive, tbh.
And then here comes the religious nutjob saying this is all fake and stupid and god made us and evolution is heresy.
I really wonder since when did religion consider evolution as heresy
but seriously human evolution is kind of mysterious
[QUOTE=BCell;32184259]And then here comes the religious nutjob saying this is all fake and stupid and god made us and evolution is heresy.
I really wonder since when did religion consider evolution as heresy
but seriously human evolution is kind of mysterious[/QUOTE]
Since small-minded, reactionary elements of the various religions (christianity included, and against whom I level this particular argument) decided to treat one particular parable in a book full of the bloody things as god-given fact. Pun intended.
Human evolution is a very interesting field, both from the paleontological side and from the evolutionary/biological side - I had some great lectures on human evolution last winter.
EVOLUTION IS A LIE
Snip
I now know better than trying to make a joke in the news section.
doesnt every fossil do this?
[QUOTE=IliekBoxes;32185152]doesnt every fossil do this?[/QUOTE]
I don't imagine they're all relative to humanity. Like, say, a duck-billed platypus's remains don't really call it into question quite like this.
[QUOTE=RainbowStalin;32185104]Yeah all you narrowminded idiots can keep finding all this stuff but its obvious thats all there to test our faith and god invented everything 4000 years ago.
Bible is a better source than fossils.[/QUOTE]
I have more faith in Science than some mythical pathological murderer who apparently created us but lets children with horrible and painful deformities be born.
snip
[QUOTE=BCell;32184259]And then here comes the religious nutjob saying this is all fake and stupid and god made us and evolution is heresy.
I really wonder since when did religion consider evolution as heresy
but seriously human evolution is kind of mysterious[/QUOTE]
Who ever said this had something to do with religion. It just seems like you're taking another opportunity to bash people who you don't agree with.
[QUOTE=chrishind10;32185219]I have more faith in Science than some mythical pathological murderer who apparently created us but lets children with horrible and painful deformities be born.[/QUOTE]
GOD WORKS IN MYSTERIOUS WAYS
evilution
[QUOTE=BCell;32184259]And then here comes the religious nutjob saying this is all fake and stupid and god made us and evolution is heresy.
I really wonder since when did religion consider evolution as heresy
but seriously human evolution is kind of mysterious[/QUOTE]
Facepunch always underestimates the quality of its posters. Everyone always says "Here comes the idiot Young-Earth Creationist!" or "Here comes the person to defend this brutal act!" and he [i]never comes.[/i]
[QUOTE=Elecbullet;32192224]Facepunch always underestimates the quality of its posters. Everyone always says "Here comes the idiot Young-Earth Creationist!" or "Here comes the person to defend this brutal act!" and he [i]never comes.[/i][/QUOTE]
WRONG
PRAISE JESUS
[QUOTE=Elecbullet;32192224]Facepunch always underestimates the quality of its posters. Everyone always says "Here comes the idiot Young-Earth Creationist!" or "Here comes the person to defend this brutal act!" and he [i]never comes.[/i][/QUOTE]
i think a lot of the time when people say things like that they're not limiting their statement to just the forum users.
[QUOTE=Elecbullet;32192224]Facepunch always underestimates the quality of its posters. Everyone always says "Here comes the idiot Young-Earth Creationist!" or "Here comes the person to defend this brutal act!" and he [i]never comes.[/i][/QUOTE]
Fundamentalism seems to be the one thing FP almost universally refuses to support. Even the few social conservatives that post here seem to keep quiet whenever fundamentalism is being discussed.
[QUOTE=Aredbomb;32192790]Fundamentalism seems to be the one thing FP almost universally refuses to support. Even the few social conservatives that post here seem to keep quiet whenever fundamentalism is being discussed.[/QUOTE]
I DISAGREE AND I REFUSE TO BE QUIET
FACEPUNCH WILL BE ENLIGHTENED
The jesus lord is our savior the earth was created in 7 days, eve was the reason we were born with original sin.
but seriously this crazy bitch down the street from me has a bumper sticker that says "evolution is a lie" Does anyone know where I could get a bigass "EVOLUTION IS SCIENCE, SCIENCE IS FACT" sticker or some shit?
[QUOTE=Awesomecaek;32194374]I DISAGREE AND I REFUSE TO BE QUIET
FACEPUNCH WILL BE ENLIGHTENED[/QUOTE]
PREACH IT BROTHA
[QUOTE=bluesky;32194869]the reason we were born with original sin.[/QUOTE]
Actually the reason we are born with original sin is because we couldn't possibly know who out of the millions born every day turn into sinners.
I am only stating the truth. Religion will come in the way of science and evolution.
Do you think ancient pre civilisation humans wore clothes?
Religion shouldn't come in the way of scientific study that humans do. Religiousness has a good goal really, but for some reason people don't give a shit about that part of it.
Basically religiousness should be about being a (good) human being
No, being a good human is not subjective. It's that by this logic people are fucking crazy, and that's often true.
(a good human being wouldn't wish to have gays stoned to death, for instance.)
I feel no shame in laughing at "Homo stem".
[QUOTE=Upgrade123;32204715]I feel no shame in laughing at "Homo stem".[/QUOTE]
nor should you
Holy shit shut up this has nothing to do with religion you nut jobs.
goddamn man
this is what's wrong with this section
everyone like, fucking
LEAPS
on religion even if the topic has little or nothing to do with it
That and misogyny.
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