400,000-Year Old Cranium Found in Portugal

A multinational research team has discovered a fossil human at the site of Aroeira, in Portugal.  From the story in EurekAlert:

The cranium represents the westernmost human fossil ever found in Europe during the middle Pleistocene epoch and one of the earliest on this continent to be associated with the Acheulean stone tool industry. In contrast to other fossils from this same time period, many of which are poorly dated or lack a clear archaeological context, the cranium discovered in the cave of Aroeira in Portugal is well-dated to 400,000 years ago and appeared in association with abundant faunal remains and stone tools, including numerous bifaces (handaxes).

The skull is considerably encrusted, still and much work will have to be done. It is long and low, with large brow ridges, a sloping forehead and a large occipital protuberance. It does not look like it has an angular torus, however. All of these characteristics are consistent with this date. Neat!

Here is the image from the short post.

Evidence For Human Behavior Pushed Back

Science Daily is running a story on some research done at Kanjera, in Kenya.  According to the story:

The fossil evidence for hominin hunting is particularly compelling. The record shows that Oldowan hominins acquired and butchered numerous small antelope carcasses. These animals are well represented at the site by most or all of their bones from the tops of their head to the tips of their hooves, indicating to researchers that they were transported to the site as whole carcasses.

Many of the bones also show evidence of cut marks made when hominins used simple stone tools to remove animal flesh. Some bones also bear evidence that hominins used fist-sized stones to break them open to acquire bone marrow.

In addition, modern studies in the Serengeti--an environment similar to KJS two million years ago--have also shown that predators completely devour antelopes of this size within minutes of their deaths. As a result, hominins could only have acquired these valuable remains on the savanna through active hunting.

The site layers are around 2 million years old.  This pushes evidence for this back into the very earliest time period of early Homo, when you had two forms running around the landscape but some two to three hundred thousand years before you had Homo erectus.

New Scientist: Is Extinction Really Such a Bad Thing?

A new exhibit at London's Natural History Museum asks just that question and concludes that, no, it is not.  Shaoni Bhattacharya at The New Scientist's Culture Lab writes:

The five mass extinctions in Earth's history wiped out swathes of life, but out of the devastation new species rose - shaped and honed by evolution - to inherit the Earth. More than 99 per cent of species that ever lived are now dead, and the exhibition hammers home the point that extinction drives evolution, which results in life in all its wondrous forms.

But it tempers this message strongly with a second sobering one: human actions are causing extinctions in a way never before seen. "If we don't do anything about it, make no mistake - it will hugely affect the world we live in," says Adrian Lister, a palaeontologist at the museum whose work on the extinct Irish elk forms part of the exhibition. "It would take the biosphere millions of years to recover."

It's not all doom, though. There are upbeat stories on display - animals we drove to the brink but then saved through conservation efforts: the Californian condor, the Arabian oryx, and China's Pere David's deer.

We have many, many tales of extinction in our own "bush." The robust australopithecines, who got out-competed by early Homo and the Neandertals come to mind.  The case of the Neandertals is peculiar, however, because it looks like they interbred with modern humans before they got gene-swamped.  Regardless, it is out of their stock and those like them that we came.

As far as conservation goes, I certainly hope we learn to understand how important it is to have our great apes around. 

Frame-Shift Mutation Linked to Sympatric Speciation in Early Homo?

According to (new?) research from the University of California, San Diego School of Medicine, a mutation creating a slightly different sugar molecule may have caused a reproductive barrier between those that had it and those that didn't in our human ancestors, possibly influencing the split between early Homo and australopithecines. Stephanie Pappas of Live Science writes:

The mutation tweaked one type of sugar molecule, Neu5Gc, produced by early hominids, the first great apes. About 2 million or 3 million years ago, just as human ancestors Homo ergaster and Homo erectus emerged in Africa, a genetic mutation halted the production of this molecule, and the prehuman immune system began to recognize it as a threat. As a result, researchers find, some hominids would no longer have been able to mate and produce offspring with other populations, potentially driving early humans apart from other apes."Over time, this incompatibility would reduce and the eliminate individuals with Neu5Gc," study researcher Pascal Gagneux of the University of California, San Diego, said in a statement.

If the date is closer to three million years, it would have considerable implications for the emergence of Homo. There are many theories about where early Homo came from and what led to the transition from Australopithecus to what became the earliest members of our line. This will shed some light on these ideas and, hopefully, spur more research in this area.

Interestingly, this research is not as new as the story makes it out to be. There was a paper written by A. Varki in 2001 that dealt directly with this data. It can be found here. Varki, however, did not make the connexion with immune suppression response but focused, rather, on how the mutation affected brain evolution.

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“The Rise of Early Homo

My newest BioLogos post is up called The Rise of Early Homo. Comments are welcome both there and here.

Lee Berger on Australopithecus sediba

Daily Web Day has a story on Lee Berger's comments at the recent American Association of Physical Anthropologists' convention. The author writes:

The researchers said that the hominin shows some surprisingly modern traits and its species may even be an ancestor of our own genus.

“We really have found something very, very odd and very unexpected,” Science Now quoted discovery team leader Lee Berger of the University of the Witwatersrand in Johannesburg, South Africa, as saying.

But other paleoanthropologists are waiting for more detailed analysis of the still-unpublished fossils before they agree on its identity or place in the human family tree.

According to new dates reported by Berger in his talk at the annual meeting of the American Association of Physical Anthropologists (AAPA), the four hominin individuals died when they fell into a “death trap” in a cave about 2 million years ago at Malapa, South Africa.

The growing concensus is that A. sediba shows up just after the appearance of Homo but that it may have been on a line that gave rise to the genus Homo. The curious thing is that there is scant evidence of Homo in South Africa but quite a bit in East Africa. In East Africa, however, there are only robust australopithecines that overlap with early Homo for a good 800,000 years. I will side with those that want more evidence first.

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