Posted on 08/08/2007 10:58:39 AM PDT by Domandred
Two hominid fossils discovered in Kenya are challenging a long-held view of human evolution.
The broken upper jaw-bone and intact skull from humanlike creatures, or hominids, are described in Nature.
Previously, the hominid Homo habilis was thought to have evolved into the more advanced Homo erectus, which evolved into us.
Now, habilis and erectus are now thought to be sister species that overlapped in time.
The new fossil evidence reveals an overlap of about 500,000 years during which Homo habilis and Homo erectus must have co-existed in the Turkana basin area, the region of East Africa where the fossils were unearthed.
"Their co-existence makes it unlikely that Homo erectus evolved from Homo habilis," said co-author Professor Meave Leakey, palaeontologist and co-director of the Koobi Fora Research Project.
The jaw bone was attributed to Homo habilis because of its distinctive primitive dental characteristics, and was dated to around 1.44 million years ago.
It is the youngest specimen of this species ever found.
The skull was assigned to the species Homo erectus despite being a similar size to that of a habilis skull. Most other erectus skulls found have been considerably larger.
But it displayed typical features of erectus such as a gentle ridge called a "keel" running over the top of the jaw joint. Analysis showed the skull to be about 1.55 million years old.
The new dates indicate that the two species must have lived side by side.
Sister species
If Homo erectus had evolved from habilis and stayed within the same location then both must have been in direct competition for the same resources.
Eventually, one would have out-competed the other.
The particularly small Homo erectus find, shown from above with the large skull from Olduvai (Tanzania) to demonstrate the gorilla-like size variation of the species. Credit: National Museums of Kenya There may have been a large size difference between the sexes "The fact that they stayed separate as individual species for a long time suggests that they had their own distinct ecological niches, thus avoiding direct competition," Professor Leakey explained.
Professor Chris Stringer, head of human origins at London's Natural History Museum, said: "Both were apparently stone tool-makers, but one possibility is that the larger and perhaps more mobile erectus species was an active hunter, while habilis scavenged or caught small prey."
It is most likely that both species evolved from a common ancestor.
Other possibilities
But the linear, ancestor-descendent relationship between the two species cannot be ruled out altogether.
Fred Spoor, professor of developmental biology at University College London, and co-author of the paper, told the BBC News website: "It's always possible that Homo habilis lived, let's say, 2.5 million years ago and then in another part of Africa, away from the Turkana basin, an isolated population evolved into Homo erectus."
After a sufficient amount of time to allow both species to develop different adaptations and lifestyles, Homo erectus could have then found its way to the Turkana basin.
With separate "ecological niches", both species could co-exist without direct competition for resources.
"But that is a much more complex proposition," Professor Spoor explained, "the easiest way to interpret these fossils is that there was an ancestral species that gave rise to both of them somewhere between two and three million years ago."
Not so similar
The fossil record indicates that modern humans (Homo sapiens) evolved from Homo erectus.
However, to some researchers, the small size of the erectus skull suggests that species may not have been as similar to us as we once thought.
On average, modern humans display a low level of "sexual dimorphism", meaning that males are females do not differ physically as much as they do in other animals.
The scientists compared the small skull to a much larger erectus cranium found previously in Tanzania. If the size difference between the two is indicative of the larger one being from a male and the smaller being from a female, it suggests that erectus displayed a high level of sexual dimorphism - similar to that of modern gorillas.
Sexual dimorphism can relate to reproductive strategies and sexual selection.
If erectus was very sexually dimorphic it may have had multiple mates at a time. This differs from the more monogamous nature of modern humans, indicating that Homo erectus was not as human-like as once thought.
The researchers dismiss the idea that the small size of the skull could be a result of it belonging to a youngster.
"By studying how the skull bones are fused together we discovered it belonged to a fully grown young adult rather than a developing juvenile erectus," said Professor Spoor.
I’ll remember to stay out of these threads next time, the ignorance makes my blood boil.
Christianity's Inquisition does not even begin to compare to science's abortion.
. . . with feathers instead of scales.
Do you have scientific proof of that? I would think it would be the other way around; that boiling blood would make one ignorant.
What, you mean a couple of carpal bones from an extinct species of peccary doesn't count?
Check your coolant level. My Chevy had that problem and it turned out it was down a couple or four pints.
The irony of course is that what “science” has been teaching about habilis and erectus has just been shown to be nothing but an ignorant falsehood.
LOL!
Your timelines are all wrong folks
http://www.answersingenesis.org/docs2005/0325Dino_tissue.asp
A couple errors on your part.
For one thing, you're automatically presuming they aren't just because they disagree with you.
Even when they can prove they did, it's dismissed off hand because of the evo litmus test you guys give them; that is, that if someone does not accept CURRENT (which can and does change regularly) scientific proclamations on what they should believe about the ToE, they will not be paid any attention.
The evos have demonstrated on this forum that to be the case, when non-science educated supporters of the ToE, who are not qualified to do so, sit in judgment on and criticize scientists who believe in creation, simply because of their stand on the ToE.
Nothing a creationist scientist can do or say will ever satisfy you unless it's a lock step adherence to the party line.
Did you not read the article, or did you not understand it?
Or do you not know how science works?
Science works by incrementally adding to the body of knowledge. It is not surprising when our understanding of something improves with more research. That is not "an ignorant falsehood" except to creationists.
Creationist "scientists" are not doing science in spite of their scientific credentials. Look at the websites of the ICR and other organizations and you will find a "Statement of Beliefs" or some such. Those statements mandate that their members place scripture and the bible above all other considerations and sources of knowledge.
That is not science, and no matter what credentials one has will not make it science. Science is adhering to the scientific method.
Oh and a language use note, quoting the article: The jaw bone was attributed to Homo habilis because of its distinctive primitive dental characteristics. I think the writer meant "distinct" (unique, singular), not "distinctive" (exceptional, excellent). But then, this is the Beeb...
I read a post on here recently that pointed out that the Inquisition came immediately on the heels of Spain’s 700 year subjugation to sharia law at the hands of the Moors. It was an interesting comment.
Hi Dave, read my post 36. Thanks for the ping!
You just don't get it - there are lot's of PhD scientists who are creationists. You can deny it, belittle it, scoff at it, whatever - it doesn't change the fact. You continue to make the same assertions on thread after thread...you continue to deny reality...you continue to be wrong!
I've explained this before, but I'll try once again.
The degrees one has do not determine whether one is doing a particular field. A well-credentialed scientist can still do junk science.
What determines what one is doing is the method one follows. If one follows the scientific method, one is doing science no matter what degrees, if any, one holds.
If one ignores the scientific method, or deliberately violates the tenets of the scientific method, one cannot claim to be doing science in spite of the degrees one has.
That is the case with most of the creationists who hold Ph.D.s in science. They are credentialed in science, but choose to follow some method other than the scientific method. They are not doing science.
Here is an example: the Creation Research Society.
The Creation Research Society has the following on their website:
The Creation Research Society is a professional organization of trained scientists and interested laypersons who are firmly committed to scientific special creation. The Society was organized in 1963 by a committee of ten like-minded scientists, and has grown into an organization with an international membership.
CRS Statement of Belief All members must subscribe to the following statement of belief:
1. The Bible is the written Word of God, and because it is inspired throughout, all its assertions are historically and scientifically true in the original autographs. To the student of nature this means that the account of origins in Genesis is a factual presentation of simple historical truths.2. All basic types of living things, including man, were made by direct creative acts of God during the Creation Week described in Genesis. Whatever biological changes have occurred since Creation Week have accomplished only changes within the original created kinds.
3. The great flood described in Genesis, commonly referred to as the Noachian Flood, was an historic event worldwide in its extent and effect.
4. We are an organization of Christian men and women of science who accept Jesus Christ as our Lord and Savior. The account of the special creation of Adam and Eve as one man and one woman and their subsequent fall into sin is the basis for our belief in the necessity of a Savior for all mankind. Therefore, salvation can come only through accepting Jesus Christ as our Savior.
Does this sound like the scientific method to you?
Any time preconceived beliefs, such as these, override the scientific method, an individual is doing something other than science. It doesn't matter what scientific degrees one may have; to agree to a set of standards such as these, which is common (whether explicit or implicit) in creationist circles, is to cease doing science and move into the realm of apologetics.
I hope you can understand what I am trying to say this time.
creationists have been saying habilis and erectus were living side by side many times over the last decade or more..The nerve to mock the assertion that homo habilis and erectus "were living side by side many times over the last decade or more"!
Indeed, the specimens archaeologists have been recovering from past few decades are overturning science:
Clearly, some ugly interbreeding of species has been going on.
-- Oops, sorry creationists, but these samples prove beyond a doubt the theory of devolution.
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