Anthropology.net

My graduate applications–probably like many of yours– are almost completely submitted by now. I spent the fall traveling around the east coast and filling out the same information on similar looking websites for hours on end. I poured over my personal statement line by line until I could recite it by heart and my girlfriend almost stabbed me. I met with professors, teasing myself with ideas of where I might end up next year.

I’m approaching my last semester as an undergraduate at Binghamton University, and if you haven’t guessed it by the context of this blog already, my envelopes were addressed to graduate schools of anthropology.

Now that I have almost finished paying a small fortune in application fees to play a lottery, I have had the time to start to catch up on some reading. While prospective graduate students might feel pessimistic about waiting to hear back about acceptances, what I’ve been skimming has sobered me up a little bit from my fall daydreams of excavations in faraway places.

I found myself searching the web reminding myself how as an anthropologist you should never expect to ever really get hired by a university. Not to say that I learned anything new.

There aren’t a lot of tenure track positions. You’re just going to have a lot of debt. It will take you a literal lifetime to pay back your loans. You’re going to be an adjunct professor and be paid less than a graduate student on a fellowship. Just don’t expect to work in academia.

That is a lot of negativity, but everyone has heard something similar. The most positive remark I hear about careers in academia is that the job market just can’t get any worse.  Surely by the time I finish my graduate work in a decade things will have turned around some, right?

For some reason like many others I am not dissuaded or in the least bit fazed by the outlook, at least at this stage in my aspirations. It is important to note I recognize that I am still in my naïve undergraduate phase. I hear in the long years of graduate school it becomes easier to get disillusioned. For now I am content. Call it unrealistic, but I’ll work my hardest and keep my fingers crossed.

I feel like most of my peers too have their eyes on the prize of a tenure track position, some time down the road. They too probably brush off knowing that very specific job listings for such positions receive hundreds of applications.

Knowing the odds, I am very curious what percentage of individuals starting work on a PhD have the intention of working somewhere other than a university. Are there a lot of you out there?

How many of you have thought about other applications of highly specialized degrees? If in eight years I am an expert on Neandertal lithic industries in southwest Belarus—as a random example– what jobs are most likely for me? Cultural resource management? Museum work?

I suppose it is something I can start thinking about, assuming I get in somewhere. If I am accepted I will have a solid seven years to mull over future directions, which should be sufficient time. Right now I am looking forward to it.

By Matthew Magnani

In 2010 the draft genome for Neandertals was released by Svante Pääbo and colleagues. It was reported that European and Asian populations are between 1-4% Neandertal—but what percentage Neandertal are you?

The company known as 23andMe recently released an analysis that claims to answer precisely this question. While personal genome sequencing has not yet hit the mainstream market, 23andMe looks at SNPs, or variations in single nucleotide pairs. Through a comparison between your SNPs and those found in the Neandertal genome draft, for a couple hundred dollars you will be given a percentage. The service has been given the name “Neanderthal Ancestry Estimator.”

Researcher extracts DNA from a Neandertal specimen

Computational biologist Eric Durand developed the project, and has previously worked on both the Neandertal genome draft and Denisova genetics.

I encourage you to take a look at an outline of the methodology, online in a white paper. Are we really at the point where a private company can tell us a likely percentage of our Neandertal ancestry for $207? I’ll let you be the judge.

By Matthew Magnani

This month in the Journal of Human Evolution, a new study on the teeth of the Dmanisi Homo erectus has been published. A site in the Republic of Georgia, Dmanisi has yielded a vast quantity of hominin fossils dating to approximately 1.8 million years ago—even an elderly individual without teeth. The discovered crania are remarkably well-preserved, and have given scientists the ability to look at our evolutionary history with higher resolution.

Based on the skeletal remains, how can we ascertain specifics about hominin diet? For this particular study, researchers used microwear analysis on two molars from Dmanisi. Microwear analysis observes the patterning left on teeth by components of specific diets. As one example, tough silicates in plants leave identifiable traces, as do other silica-based sands that end up being chewed.

Comparisons in wear patterns were made with Dmanisi H. erectus and African H. erectus as well as the genus Australopithecus and earlier Homo, to get an idea of where the Dmanisi hominins fit in on the spectrum of microwear diagnostic traits. These diagnostic traits include heterogeneity of the tooth surface, as well as complexity in the roughness of the tooth surface. To give you an idea of general evolutionary trends, Australopithecines typically had larger teeth and thicker enamel to break down tougher, lower quality foods. As later Homo emerged, teeth tended to get smaller and enamel thinner.

The results indicated that the molars of Dmanisi Homo erectus were very similar to African Homo erectus in general. However, there were also characteristics found to be consistent with other earlier hominin species. Overall the authors cautioned against drawing conclusions with such a small number of teeth, saying that meaningful statistical results are unattainable based on the sample size.

According to authors, the wear patterns on the Dmanisi teeth are indicative of hominins that exploited a range of foods. It seems then that versatility and not specialization is what defines H. erectus in both Africa and Europe. The ability to take advantage of a larger resource base is no doubt one of the factors that allowed the first hominins to spread out across such an expansive area.

By Matthew Magnani

Pontzer, H., Scott, J.R., Lordkipanidze, D., Ungar, P.S. 2011.“Dental microwear texture analysis and diet in the Dmanisi hominins.” Journal of Human Evolution 61:683-687.

Last week at the Royal Society in London, research was presented suggesting that Neandertals not only interbred with H. sapiens sapiens, but that their genes were helpful to modern people moving out of Africa.

This pioneering study was led by Peter Parham of Stanford University, and was only possible after the draft genome of H. neanderthalensis was published. The researchers looked at human leukocyte antigens (HLAs), genes important to the functioning of the immune system.

Different regions of the world are known to have unique HLAs, because different variations create specific disease resistances. It would have been advantageous for the earliest modern humans to breed with a species (or subspecies) already adapted to living in a different climate. Moderns could have picked up helpful genes that were already in existence from Neandertal populations, which would have possibly allowed their populations to expand more rapidly. Why wait for random mutation when you can interbreed with a people already successfully adapted to an area?

Neandertal Child Reconstruction

While only approximately 6% of the modern European genome was contributed from earlier hominins, around half of specific HLAs can be attributed to these earlier forms of people. As a form of further substantiation, Europeans have HLA variations present within the Neandertal genome not found in Africans. Interestingly, Asian populations today also have a variation not present anywhere else, which could indicate Denisovan (mystery Siberian hominin) admixture.

As if the draft sequence showing interbreeding was not enough last year– this study has raised the bar on the type of information we can hope to glean from looking at ancient DNA. There was a time when archaeology and anatomy were the only windows we had into our ancestral relatives. It will be exciting to see what is uncovered next.

By Matthew Magnani

For many years, the use of fire has been central to the discussion of human evolution. When was fire first controlled, and when was it first actually made by man? These are questions that rise again and again, but with scant early proof. Recently in the online journal Fire Ecology, an environmental scientist discusses what could be the earliest regular source of fire for our earliest ancestors (or potential ancestors).

Maybe an unconventional source for speculation on human origins, Michael Medler is an associate professor of environmental science at Western Washington University.  His paper can be broken into two sections, one based on reasonable observations in his specialty, and the other of speculation outside of his field (which in all fairness, the author sort of points out himself).

For millions of years in the African Rift Valley, volcanic activity went through periods of relative stability. Early groups of hominins going back millions of years would have been had access to lava flows, and in turn the benefits of heat and fire. Could it have been here that the earliest hominins started to add fuel to keep a fire going, keeping close to it for protection or warmth?

Homo erectus, a species that likely moved out of Africa aided by fire.

Maybe– but as Medler points out it is impossible to tell archaeologically. It is difficult enough for experts to determine fire usage in later instances, let alone millions of years ago in Africa.  If the earliest fire-users were in close proximity to lava flows, it is possible that the evidence would never be found. If charred bones turn up, who is to say that they were not burned by a natural fire? For now, this type of theory will remain almost strictly without archaeological evidence based simply on the principle of poor preservation.

However, the author states that there can be strong circumstantial evidence in support of his claims. If times of volcanic activity coincide with the presence of hominin species, this could perhaps be considered suggestive. As one example, Medler notes a period consistent with the emergence of Homo erectus.  Before 1.8 million years ago, there was a time of volcanic activity that was stable for about 200,000 years. This period overlaps with both the appearance of Homo erectus and their dispersal out of Africa—where knowledge of fire would have been an important factor.

There were many parts of Medler’s paper that had me questioning its integrity, namely the section on the use of tools.  While the sections that had me shaking my head were under the subheading “speculations and just so stories” I do not think this excuses him from their inclusion. He writes– without citation—-about how hand axes would have been more useful in cutting fuel than meat.  Where he got this information, I’m not really positive.

While this article does not seem to have been done in a circle of paleoanthropologists, the core ideas should get you thinking. Looking at volcanoes as a potential source of fire is intriguing, mainly because of the consistency with which they are present historically. Perhaps the next paper will have an anthropologist as a co-author.

By Matthew Magnani

Medler, M.J. 2011. Speculations about the effects of fire and lava flows on human evolution. Fire Ecology 7(1): 13-23. doi: 10.4996/fireecology.0701013

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.

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.

Neandertals have long been touted as a species with “hyperarctic” adaptations. Their stout proportions and shortened distal limb segments are often explained to conserve heat. Similarly, the Neandertal cranium is traditionally said to be cold adapted. An article released on December 22^nd in the Journal of Human Evolution challenges these traditional notions, specifically those about Neandertal nasal adaptations.

The Neandertal nasal apparatus has conventionally been cited as cold adapted mainly because of the enlarged sinuses. The authors of this article, among them Chris Stringer, cite evidence that larger sinuses are not in fact typical of cold weather mammalian species.

Through observation of human populations and studies on other mammals, cold weather is more highly correlated with smaller sinuses. That is, animals from more northerly locations typically have smaller sinus cavities. As an example taken from lab studies, rats raised in colder conditions also show smaller sinus cavities.

But are Neandertal sinuses even large, as is typically maintained? The authors of this paper argue that there is nothing large about them. Through examination of Neandertal remains, the sizes of the frontal and maxillary sinuses actually fell within the range of Homo sapiens from temperate climates.

The Forbes’ Quarry Neandertal (left) and H. sapiens skulls. Frontal sinus in purple, maxillary sinus in red. Photo from Rae et al., 2010.

This study is very suggestive that Neandertal nasal anatomy is not due to cold weather adaptation. To be cold weather adapted, the sinuses would be smaller and not larger, as many anthropologists have maintained since the first remains were discovered. Not only are the sinuses not small, they are not large- which speaks to a larger problem. How many other basic assumptions do we take as fact just because they have been around for so long?

If not cold weather, what could have caused the differences in facial anatomy between H. neanderthalensis and H. sapiens? The authors of this paper do not offer many answers, but offer a couple of possibilities. Differences in masticatory stress (utilizing teeth as a tool, for example), or genetic drift are two potential reasons discussed.

This paper may be taking another step in overturning traditional understanding of Neandertals as a cold weather species. Generations of anthropologists have passed knowing that Neandertals differed in facial anatomy due to cold weather adaptation, unsubstantiated by data.

Rae, T.C., Koppe, T., Stringer, C.B. (2010).  The Neanderthal face is not cold adapted.  The Journal of Human Evolution. Article in Press.