Anthropology.net

Carol Ward1, William Kimbel, and Donald Johanson have published a paper in Science on the arch seen in a newly discovered fourth metatarsal of Australopithecus afarensis (AL 333-160). A lot of the popular press are publishing misleading headlines that this proves bipedalism in australopithecines. No, we’ve known they were bipedal — we just didn’t have a true idea as to what extent they were bipedal. So a find like this helps investigate the degree of bipedalism.

AL 333-160 left fourth metatarsal in dorsal, lateral, medial, plantar, and proximal views.

How does this tell us how bipedal A. afarensis were?

) Box plots of angular relations of the proximal and distal metatarsal ends to the diaphysis in chimpanzees, gorillas, humans, and AL 333-160.

If you’ve ever had the pleasure of visiting a podiatrist, you’d know flat feet are not conducive to bipedalism. The two-way arch helps support upright walking and distribute recoil force. Other great apes like, chimps and gorillas have flatter feet than us. The authors of this paper confirmed this by comparing the fourth metatarsal of chimps, gorillas, and humans to AL 333-160.

On all their comparisons, AL 333-160 fell within range of humans. There were some occasions where there’s a lot of gray area which I’ll address later. Nonetheless, to the right you can see the best comparison, in my opinion, which the comparison of the arch of the diaphysis of the bone between the two species. You can have a look at the rest of the figures here.

The problem I am seeing here is that this metatarsal is not Lucy’s (AL 288-1). AL 333 is designated to fossils from the site where the “First Family” came from and not the same  locality as AL 288. Nonetheless, they are not the same individual. Kimbel is quoted in the BBC News, saying,

“Lucy’s spine has the double curve that our own spine does,” Professor Kimbel said.

“Her hips functioned much as human hips do in providing balance to the body with each step, which in a biped of course means that you’re actually standing on only one leg at a time during striding.

“The knees likewise in Lucy’s species are drawn underneath the body such that the thighbone, or femur, angles inwards to the knees from the hip-joints – as in humans.

“And now we can say that the foot, too, joins these other anatomical regions in pointing towards a fundamentally human-like form of locomotion in this ancient human ancestor.”

This is a flawed association to make; a form of what I would call confounding bias. We don’t have Lucy’s 4th metatarsal to see what it looks like and unfortunately we don’t have the rest of the this specimens skeleton to say it looked like Lucy’s. In fact, we have very little australopithecine appendicular and skeletons other than AL 288-1 (most notable are AL 129-1 and STS 14). So how can Kimbel say that the foot joins other anatomical regions when we don’t know what the other regions really looked like?

See, the n of this sample is 1. Looking at the intervals in the figures, especially Fig 3 & 4, there a a significant amount of variation in humans and chimpanzees that overlap. Chimps aren’t bipedal but we are. So imagine you are a paleoanthropologist way in the future looking at one metatarsal of a now-current then-ancient chimpanzee way and comparing it to a humans — surely you could make the same conclusion as these three have. And herein lies the big issue with sensationalism… as is the problem often in paleoanthropology, we just don’t have many comparative samples but people want definitive conclusions.

Ward, C., Kimbel, W., & Johanson, D. (2011). Complete Fourth Metatarsal and Arches in the Foot of Australopithecus afarensis Science, 331 (6018), 750-753 DOI: 10.1126/science.1201463

Very rarely is an entire family group of hominins buried and fossilized at the same time. It is even rarer for paleoanthropologists to discover such an assemblage. Fortunately for science but unfortunately for the hominins, caves occasionally collapsed on entire social groups.

Map of El Sidrón

At a site known as El Sidrón in Spain, excavations have been ongoing since 2000. To date, 12 Neandertals have been discovered in a context that points to a single geological event, circa 49,000 years ago. A group of 12 Neandertals is consistent with previous estimates of around 10 individuals per group.  At least six adults, three adolescents and four younger individuals were buried at once, most likely during a storm. The cold conditions of the cave system and immediate burial of the remains not only preserved the bones well, but were also ideal for DNA.

The remains were sexed based on both morphology and DNA analysis. After sex was determined, anthropologists identified the different Neandertal lineages based on mitochondrial DNA. Several of the adults were found to be male, and the other three female. It was discovered that all three males belong to the same matrilineal group, while each respective female has a different haplotype. When compared to modern Europeans, the authors noted that there is significantly less genetic diversity within the mitochondrial genome.

These results strongly imply that Neandertals exhibited patrilocal mating behavior. Females were the ones who would have changed family groups, not males. This type of insight into an extinct species is unique, thanks to the quality of DNA preservation available at El Sidrón.

Another interesting point of discussion in the study relates to Neandertal interbirth interval. One of the females was linked by DNA to two of the younger individuals, approximately several years apart in age. If the anthropologists are correct about the relationship, this puts the interbirth interval for Homo neanderthalensis at a value similar to hunter-gatherer groups today. This data, if replicated with other Neandertal individuals, could eventually dispel differential reproduction as a potential cause for Neandertal disappearance.

Knowing about Neandertal group dynamics could provide crucial clues as to why they went extinct. Future analysis of the remains recovered at El Sidrón will no doubt give more insights into our closest extinct relatives, and perhaps even why Homo sapiens flourished and Neandertals declined.

By Matthew Magnani

Lalueza-Fox, C., et al. (2011). “Genetic evidence for patrilocal mating behavior among Neandertal groups.” PNAS . January 4, vol. 108 no. 1 250-253.

Do archaeologists care about the living? Yes, but like all people, we focus on those aspects of a story that are of greatest interest to us. That’s why I have tuned out much of the news coming out of Egypt over the last few weeks. I casually skimmed through articles about the protests, the motivations of the protesters, political ramifications for the region and for me as an American, and even the tragic loss of life. But when Egyptian antiquities were endangered, I began to pay close attention! As a kid, I was inspired by Indiana “It belongs in a museum” Jones. What happens when the museums themselves are threatened? Archaeological materials are one of the many casualties of war and civil unrest, as recently seen in Iraq.

During the Egyptian protests, the Cairo Museum, one of the most significant repositories of artifacts in the world, was raided by looters. Thankfully, it appears that none of the museum’s famed mummies were damaged and, in fact, some protesters defended the museum from looting. Dr. Zahi Hawass, head of Egypt’s Antiquities Department, even ridiculed some looters for stealing souvenirs from the museum gift shop while leaving priceless artifacts untouched. It could have been much worse, since the museum’s collections are truly irreplaceable, and their theft would’ve represented a great loss to humanity.

From the perspective of archaeological preservation, it was a relatively happy ending. Wait…was I really more outraged by the prospect of stolen artifacts and ransacked mummies than hundreds of deaths? Maybe 24-hour global news cycles have desensitized me to death tolls and modern human tragedy. Archaeologists, especially, have been accused of insensitivity toward living people (insert your own joke about archaeologists “preferring their informants dead” here). Sometimes this reputation is deserved – long hours poring over bones and stones in laboratories can dull a person’s sociability. But archaeologists are anthropologists and, as the anthropology.net motto says, we go “Beyond bones & stones.” Archaeologists are as focused on people as any other branch of anthropology. We reconstruct past human behavior from material remains, work with living and descendant communities to better understand the past, and do our best to share archaeology with everyone. Ideally, we go into anthropology because we are human beings who care about our fellow human beings, past and present. And, if our priorities sometimes need adjusting, world events remind us to pay attention to living people and dynamic political situations in addition to mummies.

What aspects of the Egyptian protests have been most meaningful to you?

- Jay Fancher

Anyone remember 2 years ago, when Survival International released some photos of an uncontacted tribe at the border of Brazil and Peru? Well an update came out, a remarkable video showing the tribe and describing what’s being done to protect them. Oh and by the way, this is part of BBC’s Human Planet.

Check out the video here.

Image by Omar A. via Flickr

I stumbled upon this news piece in The Times regarding archaeology in Saudia Arabia. I wanted to share it with you all because of last week’s discussion of handaxes from the neighboring UAE. The article describes how archaeologists have been using Google Earth to survey for sites and have identified possibly 2,000 or so potential ones in Saudia Arabia. Now using Google Earth to do some armchair archaeology is nothing new really, there are examples from 2005, 2006, 2008 and 2010.

But we all know how strict Saudia Arabia is. One of their many impositions has traditionally been against archaeology — fearing that discoveries may disrupt the foundation of it being a cradle for Islam. From the article,

David Kennedy, a professor of classics and ancient history at the University of Western Australia, used Google Earth satellite maps to pinpoint 1,977 potential archaeological sites, including 1,082 teardrop shaped stone tombs…

…But few archaeologists have been given access to Saudi Arabia, which has long been hostile to the discipline. Hardline clerics in the kingdom fear that it might focus attention on the civilisations which flourished there before the rise of Islam – and thus, in the long term, undermine the state religion.

In 1994, a council of Saudi clerics was reported to have issued an edict asserting that preserving historical sites “could lead to polytheism and idolatry” – both punishable, under the Kingdom’s laws, by death.

This is not surprising to many. What is surprising was this tid bit:

Saudi Arabia’s rulers have, in recent years, allowed archaeologists to excavate some sites, including the spectacular but little-known ruins of Maidan Saleh (Correction its really Mada’in Saleh), a 2,000 old city which marked the southern limits of the powerful Nabataean civilisation.

For the most part, though, access to ancient sites has been severely restricted.

There are a lot of examples where traditions, governments, etc. get in the way of phenomenal discoveries. However, there are few where objection relaxed. I’m hopeful we’ll see more archaeology conducted on the Arabian peninsula, but I’ll think we’ll be seeing more from the more liberal areas like the Emirates.

Related Articles

• Archaeologists Find 1,082 Ancient Tombs in Google Earth [Science] (gawker.com)
• Archaeologists Find 1,082 Ancient Tombs in Google Earth [Science] (gawker.com)
• Google Earth finds Saudi Arabia’s forbidden archaeological secrets (telegraph.co.uk)

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