The hunting abilities of humans and dogs, the tendency of game animals to herd up or take other actions to avoid predation, etc., if disassembled and reassembled with the same actors playing somewhat different roles, give you a sheep herder, a protecting breed of dogs (like the Great Pyrenees or other mastiff type breeds), a herding dog (like a border collie) and a bunch of sheep, cattle, or goats.

Even human hunting with dogs (not herding domesticated animals) involves a reorganization of tasks and abilities, all present in non-dog-owning human ancestors and wolves (dog ancestors), but where the game are, as far as we know, unchanged. Human hunters documented in the ethnographic record, all around the world, had or have dogs, and those dogs are essential for many hunting types. The Efe Pygmies, with whom I lived in the Congo for a time, use dogs in their group hunting, where they spook animals into view for killing by archers, or drive them into nets that slow the game down long enough to be killed. The Efe actually get a lot of their game by ambush hunting, where a solitary man waits in a tree for a game animal to visit a nearby food source. He shoots the animal from the tree with an arrow. But, even then, the dog plays a role, because the wounded animal runs away. The trick to successful ambush hunting is to do it fairly near camp so you can call for help when an animal is wounded. Someone sends out a dog, and the dog runs the animal to ground. And so forth.

Scientist and science writer Pat Shipman has proposed another important element that addresses a key question in human evolution. Neanderthals, who were pretty much human like we are in most respect, and our own subspecies (or species, of you like) coexisted, but the Neanderthals were probably better adapted to the cooler European and West Asian environment they lived in. But, humans outcompeted them, or at least, replaced them, in this region very quickly once they arrived. Shipman suggests that it was the emerging dog-human association, with humans domesticating wolves, that allowed this to work. Most remarkably, and either very insightfully or totally fancifully (depending on where the data eventually lead), Shipman suggests that is was the unique human ability to communicate with their gaze that allowed this to happen, or at least, facilitated the human-dog relationship to make it really work. We don’t know if Neanderthals had this ability or not, but humans do and are unique among primates. We have whites around our Irises, which allow others to see what we are looking at, looking for, and looking like. We can and do communicate quite effectively, and by the way generally viscerally and honestly, with our glance. This, Shipman proposes, could have been the key bit of glue (or lubricant?) that made the human-dog cooperation happen, or at least, rise to a remarkable level.

The Invaders: How humans and their dogs drove Neanderthals to extinction, by Pat Shipman, outlines this theory. But that is only part of this new book. Shipman also provides a totally up to date and extremely readable, and enjoyable, overview of Neanderthal and contemporary modern human evolution. Shipman incorporates the vast evidence from archaeology, physical anthropology, and genetics to do so, and her book may be the best current source for all of this.

This is a fantastic book, and I highly recommend it. Shipman also wrote “The Animal Connection,” “The Evolution of Racism,” “The Wisdom of the Bones: In Search of Human Origins,” and several other excellent books on human evolution and other topics. Shipman, prior to becoming mainly a science writer, pioneered work in the science of Taphonomy, developing methods for analyzing marks on bones recovered from archaeological and paleontologic sites, such as those marks that may have been left by early hominins using stone tools to butcher animals.

Seriously, go read The Invaders: How humans and their dogs drove Neanderthals to extinction.

More here, including lots of text. Teachers, you could probably find a use for this in your classroom.

“We are working like crazy at the moment,” says Pääbo, adding that his Max Planck colleague, computational biologist Richard Green, is coordinating the analysis of the genome’s 3 billion base pairs.

Comparisons with the human genome may uncover evidence of interbreeding between Neanderthals and humans, the genomes of which overlap by more than 99%. They certainly had enough time for fraternization — Homo sapiens emerged as a separate species by about 400,000 years ago, and Neanderthals became extinct just 30,000 years ago. Their last common ancestor lived about 660,000 years ago, give or take 140,000 years.

Nature

Despite the remarks made in the Nature coverage about interbreeding, Svante has indicated in previous discussions about this genome that there is nothing to indicate this in the present analysis.

This study examines the genetic affinities of various modern human groupings using a multivariate analysis of morphometric data. Phylogenetic relationships among these groupings are also explored using neighbor-joining analysis of the metric data. Results indicate that the terminal Pleistocene/early Holocene fossils from Australasia exhibit a close genetic affinity with early modern humans from the Levant. Furthermore, recent human populations and Upper Paleolithic Europeans share a most recent common ancestor not shared with either the early Australasians or the early Levantine humans. This pattern of genetic and phylogenetic relationships suggests that the early modern humans from the Levant either contributed directly to the ancestry of an early lineage of Australasians, or that they share a recent common ancestor with them. The principal findings of the study, therefore, lend support to the notion of an early dispersal from Africa by a more ancient lineage of modern human prior to 50 ka, perhaps as early as OIS 5 times (76-100 ka).

What this new research is telling us is something that has been emerging as the most likely scenario for some time now. Homo sapiens arose in Africa and spread around that continent, and into southern regions of the rest of the Old World (best documented in southwest Asia) including Australia. Subsequently, there were significant and widespread and fairly complex movements. This means, for instance, that the skeletal remains found several tens of thousands of years ago in, say, Europe, may bear much less relationship to modern Europeans than they do to modern people somewhere else. Upper Paleolithic Europeans together with current or recent humans can be seen as one closely related group that does not include the ancestors of early Australasians. The two larger groups do, of course, share an earlier common ancestor.This study also finds that the earlier group is (physically) marginaly closer to Neanderthals than with Upper Paleolithic Europeans. This would not be surprising if either there was intermixing between early “modern humans” and Neanderthals (not strongly suggested by the DNA in other studies) or if the traits being studied were simply retained in both populations, with subsequent changes in traits (from the Upper Paleolithic onwards) being somewhat more rapid (which does conform to other studies).Here is the simplified results of the detailed analysis presented in this paper:From Figure 4: Linearized neighbor-joining trees describing the phylogenetic relationships among groupings of the genus Homo based on (a) size/shape and (b) shape distances. EA, early Australasians; EMH, early modern humans from the Levant (Skhul/Qafzeh); UPE, Upper Paleolithic Europeans.

The observed pattern of relationships between the early modern humans from the Near East and modern human population samples from elsewhere is consistent with the early-dispersal hypothesis described in the recent literature … assuming the Levantine early humans represent either a source population for the initial dispersal out of Africa or a population that experienced significant gene exchange with the source population prior to dispersal. The observed relationship could have also resulted from recent common ancestry for the Levantine early humans and an African source population. Morphological convergence seems to be an unlikely explanation for the observed pattern of relationships given the concordance of results from size/shape and size-corrected shape data sets. Nevertheless, the possibility of convergence or homoiology must be considered….The results presented here hint at the possibility of the existence of two lineages of modern humans (H. sapiens) outside of Africa, one more ancient than the other. The notion of a distinct ancient lineage of modern humans expanding across southern Asia into Australasia is supported directly by recent ancient mtDNA work describing a very ancient sequence in a sample of early Australians … In addition, research on the coevolution of human parasites, including head lice, tape worms, bed bugs, and the human T-cell lymphotropic virus (HTLV), also seem to indicate that there may have been two lineages of humans throughout much of our evolutionary history

SCHILLACI, M. (2008). Human cranial diversity and evidence for an ancient lineage of modern humans. Journal of Human Evolution DOI: 10.1016/j.jhevol.2007.10.010Related posts:Study Suggests Increased Rate of Human Adaptive Evolution

Welcome to the Four Stone Hearth Blog Carnival #33, ‘specializing’ in the four fields of anthropology. The previous edition of 4SH can be found at Testimony of the Spade, and the next edition will be hosted by Our Cultural World. The main page for Four Stone Hearth has additional information on the carnival, and you can submit entries via Blog Carnival.

The usual rule with blog carnivals is “one post per blog.” This rule is ignored because in several instances, a post was self-submitted (which is the usual way posts are submitted to carnivals) from a particular blog, and a different post was nominated for that same blog. It would be wrong to ignore either kind of submission, so I chose to ignore the one post per blog rule.

The order of listings here is in the order that they appear on my computer screen given the technology I’m using to keep track, with only one very logical exception. The decision to place each post in a particular subfield category is arbitrary and capricious.

If you submitted a post and do not see it, this is because I screwed up. I receive several hundred emails a day, so this is possible (actually, likely). Just send me an email with your link and I will put it in the carnival right away. Similarly, if you find errors or other problems, just let me know. Don’t yell at me, just tell me what to fix.

If you have a post on this carnival, please link to the carnival from your site.

This is an exceptionally outstanding set of posts for this or any carnival. I’m sure you will enjoy visiting and reading each and every one of these submissions.

Sociocultural Anthropology

Image and Text at Kati en Bici

…[A] lecture by Xu Bing titled “Between Image and Text” caught my attention. Xu Bing is a graphic artist who works mainly with print-making. His work explores the communicative balance between images and text. … Xu Bing had spent three years carving 4,000 wooden character-stamps to make the scroll. A non-Chinese-reader would look at the scroll and see nonsense, but assume that a Chinese-reader would find meaning in it. … However, the characters Xu Bing had carved were, in fact, nonsense. They were fake. They did not exist among the thousands and thousands of real Chinese characters floating around in reader/writer repertoires. … So, what does a piece like this say?

A different sort of landscape photograph at Kati en Bici

Ken Gonzales-Day wandered around California taking pictures of trees for his series Hang Trees. These trees were (or might have been) used in lynchings in the 19th century. Landscape photographs often neglect considerations of human interaction and influence, reproducing the classic definition of Nature as “a place without humans.” Therefore, the places where humans are is not part of Nature. By focusing on trees used in lynchings, Gonzales-Day is taking an image generally taken to symbolize natural beauty, peace, and strength and reconstructing the landscape as a point of social conflict between human beings

Anthropological research: Online dating as disappointing as the real-life dating scene at antropologi.info

Sounds familiar: People on online dating sites are experiencing frustration because it does seem that the internet in many ways is just the same old bar scene. This is one of the findings of research by anthropologist Susan E. Frohlick. She is conducting an ethnographic study of online dating among women age thirty and above.

Australian anthropologist is Japan’s first-ever foreign geisha at anthropologi.info

A documentary film-maker and academic with a doctorate in anthropology from Oxford University, Fiona Graham has just become what she says is the first non-Japanese in 400 years to debut as a geisha. But she hasn’t become a geisha for private reasons: She is now recording her life on film

‘Cultural studies’ as a term of abuse at Savage Minds

In my neck of the woods ‘cultural studies’ is a term of abuse. In fact it functions a bit like the phrase ‘family values’ but in reverse. ‘Family Values’ is a completely amorphous concept, but being labeled with it means (in certain circles) that You Win, while managing to make the term ‘cultural studies’ stick to what someone else does is–regardless of what this term actually means–means They Loose. … There seems to be two versions of this sort of labeling. The first is when professors consider themselves ‘scientific’ while their foes are ‘just doing cultural studies’.

BBC: “Aboriginal archive offers new DRM” at Open Objects

It’s a fascinating example of how real world community practice can be translated into online viewing. As the article says, “[f]or example, men cannot view women’s rituals, and people from one community cannot view material from another without first seeking permission….”

Archaeology

One of Rome’s major monuments has gone missing at Archaeoastronomy

What is there on the Campus Martius? … The Campus Martius was an area of ground on the north side of Rome, prone to swampiness. It lay outside the the early boundaries of Rome, which meant it could be used for a variety of things not allowed in the City. It’s here the Mausoleum of Augustus is found. There are temples and altars. It was also the closest place to the walls where the army could legally muster. This made it an important area, so it’s not surprising that Augustus gave it his attention. One of the things he set up there Heslin notes is an obelisk. We have a record of the erection of the obelisk and its use from Pliny’s Natural History …

Five Southeast Asian archaeology sites to visit… at SEAArch

Forget Angkor. Sure, it’s one of the largest religious monuments in the world, and you gotta admit that with spectacular architecture, sculpture and bas-reliefs there’s no wonder over two million people visited Cambodia last year. But the archaeological sites in Southeast Asian are so much more than the 11th century temple to Vishnu.

Neanderthals, Now in Color! at A Very Remote Period Indeed

Over the past few years, pigment use has been claimed to differentiate the symbolic capacity of Homo sapiens from those of Neanderthals, and as one of the defining elements of ‘modern behavior.’ This is partly why the discovery of pigment use – presumably by early Homo sapiens – dating back to 167 kya in South Africa was such big news this past fall (Marean et al. 2007). The basic idea here is that the purposeful collecting and shaping of blocks of coloring material is indicative of behavior in which colors were used to transmit socially-mediated information….

UFOs versus the Rainbow Serpents at Archaeoastronomy

One of the advantages of tripping to other libraries is that you get to browse journals you’d otherwise miss. One example is the Journal of the Royal Institute for Anthropology, which I wouldn’t see at Leicester. That is a pity because I’m missing some stuff like Close encounters: UFO beliefs in a remote Australian Aboriginal community by Eirik Saethre.

The Portable Antiquities Scheme and the Indifference of Government at Archaeoastronomy

Like many works of genius the PAS is deceptively simple. It’s a scheme that encourages people in England and Wales to report archaeological finds. That’s people. not archaeologists. I know archaeologists are people too, but this is an open scheme. It allows all sorts of people to participate, not only in putting information in, but getting information out. If you visit the PAS website you can browse their photos and interrogate their databases. In terms of providing a service of use to everyone, there isn’t anything like it anywhere else in the world. Great but why does it need to be a national scheme?

Two Carausian Aurei from the Midlands at Portable Antiquities Scheme

Two gold coins of the emperor Carausius have just been found on a construction site in the Midlands. They were reported to the Portable Antiquities Scheme and archaeologists are investigating the find further. Gold coins of Carausius are extremely rare, until now only 23 being in existence. The last example found was in 1975 in Hampshire and it is quite possible that we will have to wait for over 30 years before another one sees the light of day.

Conspiracy Theories as Historical Just so Stories at Archaeoporn

In a recent episode of the Simpsons, we are taken back to the 90’s and introduced to Marge’s time at college. As her story unfolds, we are introduced to her history professor, a younger and more lecherous (hopefully) version of Howard Zinn. Every lecture of this young firebrand (who just seems more interested on the effect of his feminist rants on the libido of his freshman students) is focused on the conspiratorial nature of white protestant land owning males in the construction of history.

The Archaeology Channel – Kuwoot Yas.Ein : His Spirit Is Looking Out From The Cave at remote central

This latest offering from The Archaeology Channel is one of the best I’ve seen, and documents the discovery and ongoing research into the 1996 find from On Your Knees Cave, of human remains dating back 10,000 years, and thus some of the oldest bones ever recovered from this part of North America.

Funerals and Feasts in Pre-Pottery Neolithic B at Archaeozoology

A recent article by Goring-Morris and Horwitz (2007) examined the evidence for funerary feasting in the Pre-Pottery Neolithic B of the Near East. The site, Kfar HaHoresh located in northern Israel, is the first centralised mortuary-cum-cult site identified in the Neolithic of the Levant, and it has been suggested that the site functioned in a manner similar to the ancient Greek amphictyony, that is a central shrine serving neighbouring villages.

Biological Anthropology and Palaeoanthropology

White skin & wheat? at Gene Expression

Regular readers of this weblog know that I have somewhat of an obsession with skin color genomics, and am puzzled by some issues, both empirical and theoretical, and have been attempting to generate plausible explanatory scenarios for what we know, and what we expect. But in the process I assume a lot, so I’m going to hit the primary background assumptions in this post, since I’ll be posting the topic a fair amount for the near future.

Human Evolution on Trial – Species – by Terry Toohill at Remote Central

Our conception of how life on earth is organised is influenced by the mythconceptions we inherit. This affects how we view both the development of species and the boundaries between them. And of course it affects how we view not just their lives but our own.

Syphilis: The View from Bioarchaeology at Afarensis

PLoS Neglected Tropical Diseases recently published an interesting article called On the Origin of the Treponematoses: A Phylogenetic Approach. The paper used data from 21 genetic regions in 26 geographically separated strains of the Treponema bacterium. … So, how and where did venereal syphilis originate? …

Syphilis origin pinpointed? at John Hawks Weblog

People sometimes wonder why it matters where syphilis came from. Or worse, they suspect that it is just a front — a way to play “blame the victim” by putting the origin of the scourge in ancient Americans. This is truly an anthropological topic — the science of origins is confounded with the subsequent cultural interactions of these populations.

Christopher Columbus’ Package of Love, Syphilis at Anthropology.net

… for some time Columbus has been blamed for bringing syphilis to the East. But a skeleton of a man was found in north eastern Britain with signs of bone lesions similar to those causes by syphilis. Preliminary dates of this skeleton suggested that the man had died around 1442, exonerating Columbus for a bit. Here’s a link to that paper, ‘”The syphilis enigma”: the riddle resolved?’ … Since then, anthropologists re-evaluated the date and suggested that the fishy diet of the region somehow affected the dating technique, making the skeleton seem older than it is. With all this confusion over paleopathology and dating techniques, a genetic analysis of the Trepanoma bacterium seemed much more logical.

Know Your Pathology: Calculus at Archaeozoology

In this edition of ‘Know Your Pathology’, we shall examine the subject of calculus, also known as calcified plaque. This consists of micro-organisms, which accumulate in the mouth, embedded in a matrix partly composed of the organisms themselves and partly derived from proteins in the saliva (Roberts and Manchester, 2005: 71). It accumulates faster when there is a high protein and/or carbohydrate diet favouring an alkaline oral environment …

Monstrous Hope: Reply to Coturnix at Greg Laden’s Blog

In my view, Coturnix’s main point is that a range of evolutionary biologists, including geneticists, reacted to Judson’s post with vitriol and nastiness because she used a few key words that struck a negative cord with them. Coturnix even claims that Coyne’s response to Judson is more wrong than Judson’s initial commentary! Well, I completely agree with Coturnix.

Linguistics

Last speaker of Eyak recently passed away at Paleoglot

…Marie Smith Jones, the last speaker of Eyak, an Alaskan language …, sadly just passed away in her sleep a few days ago. Maybe most people wouldn’t bat an eye to that tragic news, but any warm-hearted ethnologist at heart should. It’s now one branch of Athabaskan-Eyak-Tlingit gone in the blink of an eye. The good news at least is that she was blessed with longevity, living to 89 years of age. Although she survived through a lot of adversities in her life, she evidently overcame them with determined strength. Unfortunately, although she begat nine children, none of them have learned Eyak because of the taboo when they were growing up of speaking a Native language, hinting at the destructiveness that racism brings.

Endangered languages at Damon Lord’s Blog

It is always terrible when a language dies. A language dies every two weeks, and it’s projected that half of the 6,000 tongues will die out by the end of the 21st century. A quick search highlights the case of the late Charlie Muldunga, the last speaker of Amurdag, … So much culture, knowledge, and tradition dies, when a language dies. Such wisdom is often locked away in its pronunciation, grammar, vocabulary amongst others.

The paper by Pushkina and Raia (“Human influence on distribution and extinctions of the late Pleistocene Eurasian megafauna”) examines sources in the literature and a number of databases for Eurasian localities. The researchers attempt to measure “species commonness” as the proportion of sites of a given time period for which a particular species is present, for about 30 species. “Commonness is a proxy of abundance of the species remains in a fossil locality or assemblage, because it is likely that within a given region a species abundant in some sites will be present in most of them…” These data were further analyzed for uneven sampling across time and other biases in the fossil record.

An important part of this analysis is the temporal framework for human presence in the region, which the authors summarize as follows:

Long before 100,000 years ago, humans coexisted with the megafauna without causing any extinction. In western Europe, there is archaeological evidence of human occupation as early as about 800,000 years ago … The Acheulean cultures are known from the Caucasus from about 583,000 years ago … Humans were present in northern Eurasia (Eurasian Plains) at about 45,000-40,000 years ago .. Anatomically modern humans inhabited western Europe at about 34,000-36, 000 years ago … The earliest modern human occupation or early Late Paleolithic occupation for southern Siberia is recorded at 43-39,000 yrs ago and they appear to have occupied all of northern Asia by 13,000 yr ago …

An overarching pattern seen in this study is that many of the megafaunal species did not overlap totally with human habitation. Hominids, being essentially tropical, kept to warmer areas while many of the famous Pleistocene megafauna were found in cooler habitats. In the mean time, humans tended to hunt the most abundant prey. As this relationship evolved, the researchers believe that many of the megafauna suffered from habitat loss due to climate change, and became rare (or went extinct) primarily because of this transition.

The relative commonnes of the large mammals of Eurasia were influenced by human activity to some extent. People became increasingly able to hunt abundant prey species, many of which, however, are still living. Humans became able to exclude large carnivores from their sites or defend their homes. By the latest Late Paleolithic populations of large mammals of the “mammoth-steppe” were already suffering from the deterioration and contraction to the north of their preferred habitat, while humans appeared to show little interest in the now-extinct species, even when a conservative archaeological approach was used that should have favored finding human influence on extinct fauna. Only the extinct steppe bison appears to have been negatively influenced by humans. Our findings are mainly consistent with the climatic explanation of the late Pleistocene extinctions in Eurasia.

PUSHKINA, D. (2008). Human influence on distribution and extinctions of the late Pleistocene Eurasian megafauna. Journal of Human Evolution DOI: 10.1016/j.jhevol.2007.09.024

Every few years a paper comes out “explaining” short stature in one or more Pygmy groups. Most of the time the new work ads new information and new ideas but fails to be convincing. This is the case with the recent PNAS paper by Migliano et al.

From the abstract:

Explanations for the evolution of human pygmies continue to be a matter of controversy, recently fueled by the disagreements surrounding the interpretation of the fossil hominin Homo floresiensis. Traditional hypotheses assume that the small body size of human pygmies is an adaptation to special challenges, such as thermoregulation, locomotion in dense forests, or endurance against starvation. Here, we present an analysis of stature, growth, and individual fitness for a large population of Aeta and a smaller one of Batak from the Philippines and compare it with data on other pygmy groups accumulated by anthropologists for a century. The results challenge traditional explanations of human pygmy body size. We argue that human pygmy populations and adaptations evolved independently as the result of a life history tradeoff between the fertility benefits of larger body size against the costs of late growth cessation, under circumstances of significant young and adult mortality. Human pygmies do not appear to have evolved through positive selection for small stature–this was a by-product of selection for early onset of reproduction.

I would like to add right in the beginning that the evolution of stature is probably, in my opinion, widely misunderstood. There are two problems. The first, which is not too related to the present discussion and that I’d like to dispense with right away, is that change over time in human stature is not easily attributed to genetic change. Secular change in body size seems in itself to be a capacity of certain mammals and may be a long or medium term response to ecological change. Increase in stature in human groups documented over the last century or more of time is not genetic change. We have no evidence that the short people … the people carrying hypothetical “shortness” alleles … were killed off differentially or failed to reproduce. Rather, increased nutrition (of some sort) seems to produce somewhat taller offspring in each generation. Perhaps there is a limit on growth that is determined by the mother. If nutritional load is increased beyond some limit, a given population produces somewhat larger (but not maximally larger) offspring, but over several generations, the full potential stature is realized.

But that is not the issue with African Pygmies, who are genetically short-statued.

The second issue is the idea that short stature is a derived adaptation in relation to “normal” or “typical” taller stature. The authors of this paper correctly point out that there is not a good single explanation for short stature. There are at least two possible reasons for this. First, we have not thought of an explanation yet, or among the list of possible explanations is the actual explanation, but we have not identified it or demonstrated it to a sufficient degree. Second, some subset of previously proposed explanations (possibly all of them?) is at work, but to different degrees in different situations. In other words, stature is an epiphenomenon resulting from multiple causes.

I would like to suggest that we begin to think of stature in a somewhat different ways. I propose that the following two things are true:

1. 1)For certain reasons, increased stature in humans is always good. Male-male competition, increased ranging behavior, and anti-predator tactics come to mind as selective forces for increased stature.
2. 2)For certain reasons, smaller stature in humans is always good. In the absence of selection for tallness, shortness has a significant energetic advantage, for instance.

The tradeoff between good reasons to be tall and good reasons to be short are always in play, so the optimal stature for a given population may shift even so dynamically that stature changes through either secular variation or allelic changes are only barely able to track the optimum.

This is why the life history approach taken by the research being discussed here is a good one. Life history theory is about tradeoffs. In the absence of a qualitative shift of some kind, an organism has a limited amount of energy that must be budgeted over short periods of time and over a lifetime. Classically, the three major “budget lines” for this energy are growth, reproduction, and maintenance (maintenance including immune system activity). Stature does not fit into one of these categories, but rather, should be responsive to all three. Stature determines a good portion of the energy partitioned into growth. Larger vs. smaller individuals have more vs. less daily maintenance demand, and producing larger vs. smaller offspring demands more or less energy.

This paper attempts to assertain if Pygmy stature is a function of nutritional variation by comparing data from Pygmies with other groups to examine the growth curve. This is largely a rehash of previous research, done some time ago, that established that African Pygmies are genetically short of stature. This is one of those rare cases where a genetic cause is not only evidenced by the appearance of the phenotype, but the gene involved is known.

The next thing they do is to estimate mortality and fertility patterns for Pygmies, and in this effort they find Pygmies to be more akin to Chimpanzees than to other humans. This result is fairly dicey, however. The ideal data for both mortality and fertility is simply not available for chimps or humans. Yes, there are data, but the sample sizes are inadqueate. In addition, their literature search indicates that Pygmy life expectancy is low, averaging 18 years and ranging from 15.6 to 24.2 years, compared to other groups including the !Kung, Ache and Turkana. The problem with this is that while !Kung and Ache life expectancy is indicated to be longer, they are not at all very much taller, and the !Kung live in a savanna environment. In other words, the comparison is being made between mostly rain forest populations with data collected from periods when disease from the outside may have a strong effect, with data from various time periods of people living in environments including those with much less disease. The authors write-off the importance of these effects but, well, they can’t really do that.

I would not be surprised if there was a link between stature and life span, but the data available at this time are not sufficient to make the case. Indeed, the relationship could easily be the opposite of what is asserted here. Life history theory would predict that growing big could produce, as a matter of trade offs, decreased life span, when comparing populations that are different in their life history parameters but otherwise similar (same species, same environment, same diet, etc.).

I still prefer the hypothesis of diet and thermoregulation as explanations for Pygmy stature and body form. The authors of this paper produce a red herring by grouping together Asian and African populations into one, ignoring what is known about the histories of the two groups. African Pygmies have been living in the rain forest for quite some time, as opposed to non-Pygmy groups who have moved into the region fairly recently. The history of Asian “Pygmy” populations is probably less well understood, but there is reason to expect a similar history. The authors cite Diamond’s conjecture that forest dwelling is not an explanation for pygmy stature because of the Asian cases, but Diamond is probably simply wrong on this. South Asian short stature groups may well have been living in rain forests much longer than other groups.

Bamberg Migliano, Andrea Vinicius, Lucio Lahr, Marta Mirazon. (2007) Life history trade-offs explain the evolution of human pygmies. PNAS Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0708024105