Giant clams and ancient human population size

John Hawks, as always, has the best incite about some new research about the giant clam population and it’s impact on early human expansion.

* The paper (Richter et al., 2008) describes a new species of giant clam, distinct from others in reproductive cycle, habitat preference and size.
* This new species is mainly found in shallow water reefs.
* Today, the species makes up a very small proportion of the total Red Sea giant clam count.
* Before the last interglacial, this species made up as much as 80 percent of the giant clam count, as assessed by shells from reef terraces. This proportion decreased around the last interglacial, and again in historic times.

This sounds like the classic megafaunal exploitation story, as it is being reported. Shells become an important debris of humans in Northeastern Africa by 125,000 years ago (Walter et al., 2000), and were important elements of the MSA along the coasts of North and South Africa (McBrearty and Brooks, 2000). So it would not be surprising if these people recovered giant clams, particularly if those clams were readily available in shallow water.

An earlier post of his helps explain some problems with conventional views on the human bottleneck hypothesis of 70,000 years ago.

These data allow a direct test of the hypothesis of a 70,000-year-old bottleneck in Africa, and they refute the hypothesis. The new data allow a powerful model of ancient African population size to be built, one that comes together with archaeological data to give us a really interesting picture of the early evolution of “modern” humans. The model can be tested with new, massive sets of information from single nucleotide polymorphisms, as well as a more detailed chronology of late MSA sites.

Photo source:  Coincidentally the photo is from Vanuatu, which would be the path taken by the early migration.  From http://flickr.com/photos/yumievriwan

 

Lived around 200,000 years ago and resembled present-day Ethiopians

Discovery News has the story on upcoming news in the Journal of Human Evolution.  It’s about the first known modern human.  A tall, thin individual — probably male — lived around 200,000 years ago and resembled present-day Ethiopians.  Yet he retained a few primitive characteristics associated with Neanderthals.

“From the size of the preserved bones, we estimated that Omo I was tall and slender, most likely around 5′10″ tall and about 155 pounds,” said University of New Mexico anthropologist Osbjorn Pearson.

Several scientists analyzed the bones, including a very detailed, comparative look at the shoulder bone by French paleontologist Jean-Luc Voisin. They concluded that, without a doubt, Omo I represents an anatomically modern human, with bones in the arms, hands and ankles somewhat resembling those of other, earlier human-like species.

Seems barbed spear points for fishing may be related. Paleobiologist Josh Trapani of the Smithsonian Institution and the University of Michigan has some interesting research on this.

Barbed bone points have been collected from the upper part of the formation, indicating a long association between the human inhabitants and the fish fauna of the Omo Valley.

 

On display: 25,000 year old Venus of Willendorf

Vienna’s Natural History Museum is running an exhibit on Venus of Willendorf.  The Venus is a 25,000 statue which could represent an ancient fertility deity (no one really knows).  She was found around the turn of the previous century and has since been joined by the French Venus of Lespugue and Russian Venus of Kostienki.

Nice curves.

 

Dinosaur and humans walking together

No, this is fake.  But a funny story…

During the 1930s and the Depression, Glen Rose residents made money by distilling moonshine and selling dinosaur fossils. Each fossil brought $15 to $30. When the supply ran low, George Adams just carved more, some with human footprints thrown in.

Since at least 1950, preachers have walked the earth in Glen Rose claiming that the fake footprints refute the scientific theory of evolution.

From the Star-Telegram.

 

Cooked food, the human brain, and technical advancement

What changed in early humans that made them suddenly advance technically and artistically?  LiveScience cites some new research:

About 150,000 years ago, a different type of spurt happened — our big brains suddenly got smart. We started innovating. We tried different materials, such as bone, and invented many new tools, including needles for beadwork. Responding to, presumably, our first abstract thoughts, we started creating art and maybe even religion.

To understand what caused the cognitive spurt, Khaitovich and colleagues examined chemical brain processes known to have changed in the past 200,000 years. Comparing apes and humans, they found the most robust differences were for processes involved in energy metabolism.

Their study focused on comparing chemical brain processes between humans and chimps, and they claim they found differences relating to energy metabolism.

Without reading the original research, there are no solid facts to prove their point, but still seems interesting.  The research was by Philipp Khaitovich of the Partner Institute for Computational Biology in Shanghai and was published in the August 2008 issue of Genome Biology.

 

The ancient green Sahara

The New York Times reports about a find of an ancient graveyard from the Sahara.  Paul Sereno, formerly a dinosaur hunter, made an amazing find.

The initial inhabitants at Gobero, the Kiffian culture, were tall hunters of wild game who also fished with harpoons carved from animal bone. Later, a more lightly built people, the Ténérians, lived there, hunting, fishing and herding cattle.

Other scientists said the discovery appeared to provide spectacular evidence that nothing, not even the arid expanse of the Sahara, was changeless. About 100 million years ago, this land was forested and occupied by dinosaurs and enormous crocodiles. Around 50,000 years ago, people moved in and left stone tools and mounds of shells, fish bones and other refuse. The lakes dried up in the last Ice Age.

Then the rains and lakes of a fecund Sahara returned about 12,000 years ago, and remained, except for one 1,000-year interval, until about 4,500 years ago. Geologists have long known that the region’s basins retained mineral residue of former lakes, and other explorers have found scatterings of human artifacts from that time, as Dr. Sereno did at Gobero in 2000.

The Sahara sounds like a much nicer place back then.

 

Anyone out there?

Hopefully not, this blog is not very interesting so far. In fact, it’s my guess that most people will be thoroughly bored by the material posted here.

I’m trying to set the bar low.  As long as I have 1 reader (myself), I’m going to consider it a partial success, since I’m at least assured my audience is engaged in the material.  Moderate success will be 2 people (I’m hoping my mother will read it).  I’ll call it a full success if I get at least 1 stranger as a regular reader.  And if I reach half a dozen, I’ll have exceeded my wildest blogging dreams.  Let’s see what happens!

The topic of this blog is human origins and pre-history, which includes a bunch of obscure disciplines in the social sciences.  Some might claim that there are already decent sources of news about this already.  But I would argue that all are too broad (e.g. from Australopithicus to World War I) or too narrow (e.g. schematic model of putative contribution of mtDNA).  Moreover, none of the major news outlets cover this news regularly, and many stories that do get published are loaded with inaccuracies.