Anthropology.net

Hans-Peter Uerpmann of the University of Tubingen has lead a team excavating the Jebel Faya site in the United Arab Emirates, right near the Straits of Hormuz. They’ve found 125,000 year old stone tools that look like early modern human tools from East Africa around the same time. They’ve published their findings in today’s Science, under the title, “The Southern Route “Out of Africa”: Evidence for an Early Expansion of Modern Humans into Arabia.”

The current understanding is what we know as anatomically modern humans (AMH) originated in Africa about 250,000 years ago. The oldest Home sapiens, known as H. sapiens idaltu, was found to be 160,000 years old, found at the Middle Awash site in Ethiopia. Then between 80k-100k years ago, modern humans began appearing in the middle east, as remains from sites like the Qafzeh cave in Israel have yielded. Most agree that AMH stayed in Africa and about 140,000 years ago they began migrating out. There was an exception, a colonization remained or failed in Israel about 100,000 years ago.

One of the hand axes from Jebel Faya, UAE (Photograph courtesy Science/AAAS)

These hand axes, pictured above, show a pattern of flaking distinct from that made by Neandertals and also dissimilar to those by ~100,000 year old Israeli tools. They are two sided and very similar to stone tools seen only in early Africa.

What this means is early humans left Africa 20,000 years earlier than thought. Just how did they do it? 130,000 years ago, there was a window of climate change. They figured this out by using luminescence dating to determine the age of sand grains buried with the stone tools. Luminescence dating is a technique that measures naturally occurring radiation stored in the sand. The data showed that 130,000 years ago, the Arabian Peninsula was relatively more warm which caused more rainfall, turning it into a series of lush habitable land. During this period the southern Red Sea’s levels dropped and was only 2.5 miles or 4 km wide. This offered a brief window of time for humans to easily cross the sea and cross the Peninsula to opposing sites like Jebel Faya.

Does this study tell us that modern humans left Africa, into Arabia and out from there? It is most certainly a possibility. However, these axes could be of an abandoned migration like the site in Israel I’ve mentioned. I say that because no genetic clade, be it from mitochondrial, Y-chromosome, or somatic genome, shows an earlier divergence of modern humans from Africa earlier than 60,000 years ago. At the very minimum a find like this tells us humans left Africa a bit sooner than we thought, but does not really tell us that these were the humans that helped seed the Eurasia.

Armitage, S., Jasim, S., Marks, A., Parker, A., Usik, V., & Uerpmann, H. (2011). The Southern Route “Out of Africa”: Evidence for an Early Expansion of Modern Humans into Arabia Science, 331 (6016), 453-456 DOI: 10.1126/science.1199113

Endurance running has been cited since the 1980’s as a possible explanation for the modern human body plan. Past studies have focused on the running abilities of species such as Homo ergaster and Homo sapiens, with little or no mention of other species or genera. Currently in press in the Journal of Human Evolution is a discussion of Neandertal running capabilities.

The authors observed the length of the calcaneal tuber of the foot, which correlates with how far the Achilles tendon will stretch during movement. For this study measurements were taken of both Homo sapiens and Homo neanderthalensis.  Species with short calcaneal tubers stretch their Achilles tendons to a greater degree, which is then returned in the form of elastic energy. Species with long tubers stretch the Achilles tendon less and therefore have a lower return of elastic energy.

White Line: Calcaneus tuber length. Red Line: Achilles tendon moment. Correlation between the two values. Photo from Raichlen et al.

Simply put, a species with shorter calcaneal tubers will use less energy when running. Anatomically modern humans have been found to have short tubers, while longer ones are found on Neandertal remains. According to the authors, this variation has significant behavioral implications.

Unlike modern humans, the storage of less elastic energy in Neandertals would have made running less efficient. However, Neandertals were not necessarily at a disadvantage in the colder climates they are often said to have inhabited. It is more likely that running over long distances would have been energetically costly to them, without having huge benefits.

Long distance running would prove beneficial in warmer climates where animals are prone to hyperventilate when chased. Modern humans would have benefitted from endurance running because it would have aided in capturing prey. The same model does not necessarily apply in colder climates. A runner could chase an animal all day in low temperatures and never have the animal succumb to heat stress or hyperventilation. It is for this reason argued that the ability to run long distances would not have been as evolutionarily valuable to Homo neanderthalensis.

Discussing endurance running provides fascinating insight into human evolution. While the ability to run long distances can be very revealing about evolutionary history, lack of endurance can be as well.

By Matt Magnani

Raichlen, D.A., Armstrong, H., Lieberman, D.E. (2011). “Calcaneus length determines running economy: Implications for endurance running performance in modern humans and Neandertals.” The Journal of Human Evolution. Article in Press.

A hunter-gatherer mother sits stirring a pot of stew over an open fire.  Her young son, eagerly anticipating the evening meal, approaches the pot and asks, “What are we eating?”  “Not sure.  Meat, I think.  Probably some other stuff,” she replies.

Okay, I made that up.  The preceding exchange would never occur between hunter-gatherers.  Or horticulturalists.  Or pastoralists.  Or most of the other subsistence systems that anthropologists study.  The mother, and usually the son, would know what was in the pot because they took part in hunting, gathering, raising, growing, or processing the ingredients.  And that’s pretty much the way it’s been for the vast majority of human history.

So how did we end up here?  An Alabama law firm is suing Taco Bell, claiming that the meat used in Taco Bell’s products does not meet the U.S. Department of Agriculture definition of “beef.”  In fact, the lawsuit alleges that the company’s meat filling is only 35% beef, with the remainder comprised of non-meat ingredients such as water, oats, modified corn starch, maltodextrin, etc.

Taco Bell asserts that their products contain 100% beef.

That’s a big difference in percentages.  Someone’s not telling the truth, or is at least being very disingenuous.  Thankfully, we humans have an established method for evaluating evidence-based claims…SCIENCE!  Yes, I can turn anything into an advertisement for science, and I hope the legal proceedings rely on solid data to resolve this dispute.

From an anthropological perspective, this issue highlights the wide, historically-unprecedented, gap between food production and food consumption in 21st Century developed nations.  We’re all food consumers, far fewer of us are food producers.  The production of our food most often occurs out of sight.  Michael Pollan [In Defense of Food and the film Food, Inc.] argues that much of what we eat is not even food in the strict sense, but rather “food products,” manufactured from food and the “other stuff” I mentioned before.

Many people seem repelled by the idea of unidentifiable “meat.”  But, like our Paleolithic ancestors, we crave fat, salt, and sugar [Martin Jones' Feast: Why Humans Share Food and Richard Wrangham's Catching Fire: How Cooking Made Us Human].  Fast food provides massive quantities of all three for a low, low price.  I had Taco Bell a few days ago, so I understand the allure of quick, cheap calories.  How we got to this point is a fascinating story, well-covered by anthropological research (please see included links and share your own in the comments).  Since we are so removed from the production of our own food products, I think it’s reasonable for consumers to know what’s in the pot – even if laboratory analysis is required to figure out the ingredients.  What do you think?

- Jay Fancher

If you don’t follow or subscribe to our sister blog Primatology.net, I want to make you aware of an anthropological post I just put up on the newly published orangutan genome. Click here to read about some of the findings, but to wet your appetite, it involves the estimated divergence of the two orangutan species at 400,000 years ago, the relative stabilitiy of their genomes compared to human and chimpanzee, and lastly the shared similarities between human and orang, and not orang and chimp.

Sumatran Orangutan (Pongo abelii)

For quick access to the primary sources, the full citations to the papers discussed are below this read more link.

Read the rest of this entry »

Map of Grape Domestication

I got some archaeobotany for you to start your weekend off right with — a new open access study in PNAS announces a genome wide association of 8,000 years of grape domestication, spanning the Eastern Caucasus to Western Europe. Lead author Sean Myles of Cornell University wrote in the abstract,

“support a geographical origin of grape domestication in the Near East. Grape growing and winemaking then expanded westward toward Europe, but the degree to which local wild sylvestris from Western Europe contributed genetically to Western European viniferacultivars remains a contentious issue. Our results … all support a model in which modern Western European cultivars experienced introgression from local wildsylvestris.”

In related wine archaeology, earlier this week, UCLA archaeologist Hans Barnard published the findings of a 6,000 year old uncorked wine barrel in Armenia. The barrel was discovered in the Areni-1 cave near the Iranian border. The results were published in the Journal of Archaeological Science, but you can read a bit more about it here.

Hope you found these two tidbits as interesting as I did. Cheers to a good weekend!

Myles, S., Boyko, A., Owens, C., Brown, P., Grassi, F., Aradhya, M., Prins, B., Reynolds, A., Chia, J., Ware, D., Bustamante, C., & Buckler, E. (2011). Genetic structure and domestication history of the grape Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1009363108

Another video to share with you, this time the trailer to Werner Herzog‘s Cave of Forgotten Dreams. This is a 3D film shot inside Chauvet-Pont-d’Arc Cave in southern France. These are some of the oldest cave paintings known. The film seems to have good reviews on IMDB and is set to be released on March 25th, 2011 in the UK.

What do you think?

Inspired by the Dodecad Ancestry Project by Dienekes Pontikos and Eurogenes Ancestry Project by David Wesolowski, Zack Ajmal (with the help of Razib Khan) has started the Harappa Ancestry Project. Zack explains the motivation behind this project,

“It is a project to analyze (autosomal) genetic data of participants of South Asian origin for the purpose of providing detailed ancestry information. So the focus of the project is on South Asians: Indians, Pakistanis, Bangladeshis and Sri Lankans.

The project will collect 23andme raw genetic data from participants to better understand the ancestry relationships of different South Asian ethnicities.

I have named it after Harappa, an archaeological site of the Indus Valley Civilization in Punjab, Pakistan.”

There was a nice deal running on 23andme about a month ago for their ancestry & health kit that worked out to be $160 for 1 year. I hopped on board, got my kit, spat in the tube and sent it off. It is currently being analyzed. My ancestry is one of the populations Zack is looking for — so I’ll be sending my data to him. I can’t wait.

If you have had a 23andme genetic testing, you should consider participating in this project. It looks to be very interesting.

This seems really fascinating.

Razib has done rounded up a nice review of Dienekes‘ Dodecad data to answer some prelim questions on the genetic of Ethiopia. Ethiopia is a very interesting cultural and paleontological area of the world. I had the pleasure of being a part of a field group several years ago and had a wonderful time. A good summary of the ADMIXTURE analysis done by Dienekes, reorganized by Razib, is shown below:

I don’t have much to add to his post, other than to hand you over there and to check it out. You may also wanna read more about the Dodecad Ancestry Project in this Nature News piece.

Do you believe in evolution?  Forty percent of Americans don’t (more on that later).  A student asked me this question on day one of the first introductory anthropology class I ever taught.  I believe that any difficult-to-answer question is a good one, and this one baffled me with its simplicity.

Short answer: yes, I believe in evolution…but why was a modern college student in the United States asking me this?  The student was intelligent, curious, and friendly.  If anyone was naive, it was me for not expecting the question.  He’d simply been shaped by our culture to see evolution as a divisive matter of public opinion – and he wanted to know where I stood on the issue.  It would have been easiest to take his question at face value, answer yes, and move on to discussing the details of human evolution.  But, like so many idealistic teachers, I grasped the “teachable moment” and ran with it (annoying the many students who already believed in evolution and wanted to get into the good stuff):

• Science is an empirical method that (at least ideally) is not based on belief.  All scientific conclusions are tentative.  Scientific knowledge is evidence-based, ever-growing, and self-correcting since new or contrary evidence can be discovered at any time.  When asked what evidence would convince him that evolution was false, biologist J.B.S. Haldane remarked “Fossil rabbits in the Precambrian.”  Like all scientifically-testable ideas, evolution is falsifiable.  If rabbit fossils are found in Precambrian layers of rock (millions of years too early), I’ll be happy to explore alternative theories!
• There is also a major difference between the general and scientific uses of the word theory.  In everyday usage, theory means a guess or speculation.  In science, a hypothesis does not rise to the level of a theory without overwhelming evidence and explanatory power.  Anti-evolutionists dismiss evolution as “just a theory,” but scientifically-speaking, this is a gracious compliment.  Charles Darwin’s theory of evolution by natural selection has survived 150 years of rigorous challenges in every field from geology to genetics.
• Evolution may be politically, culturally, and emotionally controversial.  In the 19th Century, Darwin’s “dangerous idea” caused spiritual crises for many.  However, in the 21st Century, biological evolution is not scientifically controversial.  It’s an understatement to say that the evidence for evolution is overwhelming.
• Finally, scientific inquiry has revealed other phenomena that I “believe” in.  I believe in a round earth, though my senses tell me it’s flat.  I believe that the earth orbits the sun, not the other way around.  I believe in sexual reproduction, not the stork theory of baby origins.  I believe in particles like quarks, though I can’t see them directly.  And I do believe in evolution.

That’s a pretty long preamble, and one that most of my students had heard in middle school or high school biology classes.  Still, I thought “Do you believe in evolution?” deserved a thoughtful answer.  These days, I might answer “Yes.  Please read Jerry Coyne‘s Why Evolution is True” to save time.  After that, we were able to move into the actual evidence for evolution, all the cool hominid skulls, etc.

Assuming that Precambrian rabbits, or comparable out-of-place fossils, aren’t found anytime soon, the reality of evolution has been scientifically proven beyond a reasonable doubt.  So, it’s no longer necessary for anthropologists to summarize the scientific method before discussing human evolution, right?  Unfortunately, in the United States, evolution is still presented as if it was a political issue and, in some cases, it does enter the political arena (e.g., school board decisions).  Informed people can have differences of opinion over political issues.  In fact, one thing that ties Americans together is the core belief that political issues should be decided democratically.  But evolution is a scientific theory, subject to empirical evidence, not public opinion…and that may be a good thing.

Gallup poll results from December 17, 2010 show that 40% of Americans believe that “God created human beings pretty much in their present form at one time within the last 10,000 years or so.”  Make no mistake, the last 10,000 years have been a fascinating part of the human story – but they’re not the whole story!  Poll results like these make me feel both discouraged and reflective.  How is this possible in a developed country with educational opportunities like ours?  What can I do to better explain the human past (ALL of it)?  There is some truth to the argument that more and better education would help.  The same Gallup poll divides anti-evolution respondents by education level:

Gallup Poll on Evolution vs. Education

So education helps, but education alone cannot overcome the cultural/religious impediments that prevent more widespread understanding of biological evolution in the U.S.  Undoubtedly, many of the survey respondents took biology or anthropology as part of their education and still hold the belief that humans are new and separate from all other forms of animal life.  One hopeful sign is that 40% is the lowest percentage of “creationists” in Gallup’s history of asking this question – down from a high of 47% in 1993 and 1999.  There will probably always be a percentage of the population that is beyond the reach of evidence, especially with an emotionally-charged subject like evolution (after all, no one is freaking out about teaching gravity in public schools).

For cultural and historical reasons too numerous to go into here, Americans are not yet ready to embrace Darwin’s grand view of life – a view that has become so much grander and more elegant over the last 150 years.  It might take another 150 years for the culture to catch up with the science.  Those of us who love the science of humanity will keep doing our part to share the evidence for evolution and its role in shaping our species.

Do you believe in evolution?