Monday, September 14, 2015

The Brachycephalic Problematic

I came across a dogblog exploring the evolution of dog brachycephaly that got me thinking.  It reminded me that Stephen Jay Gould hypothesized that dog brachycephaly might have been a subconscious human preference that neotenized most breeds.  Pugs and spaniels are cuter than timber wolves. 

The English word, cuteness, has been used to describe neoteny and it seems in humans both sexes are oppositely attracted to cute features in each other, most of the time.  All humans exhibit some theorized forms of neotony, from glabrousness to light hair; but if you've ever been to an East Asian country or Japan, you may be familiar with Kawaii, which is G4-level cuteness.  Asian culture has been variously argued as encouraging rapid neoteny and gracialization in that part of the world.

In general, primates are often bracycephalic as infants and then become progressively long-headed as they mature.  (And to clarify, newborn alien heads don't count)  So brachycephaly in East Asians or some Caucasians may be an indicator that this too is a sexual-driven change, not random ping-pong balls bouncing off the walls of the universe.  (I will point out now that brachycephaly here refers to all correlated features of the skull, not a simple cephalic number)

Journal of Heredity (1921) Volume 12, pg 421

Almost all domesticated animals, minus the horse, have tended to become increasingly brachycephalic over time (Darwin) and there is a correlation between the length of the skull and the length of the limbs in most mammals, including humans (Henry Osborne); this also convincingly latitude/temperature correlated (Allen's rule).

Many correlations with shortened skulls are known throughout the face and skull of most mammals (Cuvier), which are generally similar in humans. Whatever the cause, what is clear is that body proportions and head-shape are the result of particular ancestry beyond natural variation.  Pugs have pups that look like pugs.

So I'll quickly interject a point concerning the Beaker folk, since they are shockingly mammals as well, not decorative pots.  The issue of Beaker brachycephaly is not a topic of simple cephalic index, one number divided by another.  Again, it is a complex system of correlated features of the face and the features of the skull.

Shifting gears now, where I was going is the question of an abrupt appearance of short-headed people in various prehistoric regions, in some cases as was once variously thought, emanating from the Zargos region or Central Asia.   Don't get too wrapped up in any of this since it's all theoretical plasma and not dogma or empirical science.

First, I'll juxtapose two papers.  One concerning "The Beaker Problem" and one, "The Sumerian Problem"  This paper:

"A Test of Non-metrical Analysis as Applied to the 'Beaker Problem'." by Natasha Grace Bartels (1998) thesis tests the classical understanding of intrusive 'heavy-boned, brachycephalic warriors' opposite to Neal Brodie's position that shape in Britain was progressively changed by using a collection of Neolithic and Early Bronze Age skulls from a Northern zone and a Southern Zone of Europe.

After lengthy discussion, Bartels gets to brass tacks on her European collection and concludes:
"This would appear to support the theory that the 'Beakers' may have been a distinct migratory population, and that the movement of Beaker vessels and associated items was not simply the result of cultural diffusion, through the trade of status items..."
This conclusion is not unusual.  In Little Poland (Budziszewski et al), Beakers are very distinct in terms of head shape, but also massive cheeks, heavy brows and high vaults.  Almost identical features for the large Hoštice I cemetary in Moravia (Eva Drozdová, 2014(?)) where the folk are also equally 'robust' and range from brachycephalic to hyper-brachycephalic. 

(An interesting Beakerwomen in Iberia-here)
I would continue, however I believe distinct shape and facial features of Beaker heads is generally well established and uncontested in European archaeology.  Even skeptics like Gordon Childe, who was deeply skeptical of the cranometric pseudo-science of his time, made a single exception for the Beakerfolk where the evidence is fairly overwhelming. 

Now, a somewhat similar controversy regarding the, not-too-well-represented Sumerians:

"Physical Anthropology and the Sumerian Problem" by Arkadiusz Soltysiak (2004)

This short paper mostly gives a history's history of race, migration and cultural change in the Mesopotamian region through the progression of anthropology.  Like the Beaker problem, there was identified an early narrative with 'short-headed' intruders, a narrative rolled back because of a complicated demographic history and spotty human remains.  But the question remains as to whether Mesopotamia's history was significantly altered by 'hill people' at different times in its history or whether several ethnic groups existed at this time, being demarcated by space or social status.   

These "whomever problems" seem to be present in more than just Childe's Western Europe or Frankfort's Mesopotamia.  Thomas Callan Hodson noted a similar phenomenon with a highland Anatolian-derived immigrant group in the Indus Valley Civilization, apart from the other Western farmers and Asians.  This is a problem in Petrie's Abydos and Naqada with a majority population that is long-headed and a small outgroup that is short-headed.  (as he saw, a distinct ethnicity)  Cyprus? How about the Pontic Steppe?  This problem rears its head there as well (no pun intended).
This is the Beaker problem.  New people or old people?

Also, another perspective by Rokus blog
Here, he argues that brain evolution has changed head-shape in AMH slowly from the hyper-focused hunters of the Upper Paleolithic to a more sedentary and specialized Modern.


  1. Haven't you mentioned elsewhere that Beaker people might have used to strap babies to a board. That alone probably causes brachicephaly, regardless of genotype.

    In any case I'd like to know on what grounds, and affecting what geographies, does the * brachy- = Beaker * correlation applies, with what intensity, etc. Is there support for the proposition or rather not or is something specific of, say, Eastern Germany?

    In the Basque Country at least BB is much older than the first signs of brachycephaly, which correspond to a small fraction of "miners" of the Bronze Age.

  2. "Haven't you mentioned elsewhere that Beaker people might have used to strap babies to a board. That alone probably causes brachicephaly, regardless of genotype."

    Possibly causing the ultra-flat occiput in some, but I caveat with other features of brachycephaly and their facial distinction. So with or without a flatten occiput, they'd still be medium to short headed

    "affecting what geographies"
    Notwithstanding the subtle regional differences and interpretations, they seem to be recognized as distinct everywhere initially. The most extreme is probably the entire Eastern sphere, (from my reading) from Poland to the Dinaric Alps where they are thoroughly alien (except a few outliers) and in Central and Southern Europe. In the Lower Rhine, hybridization happened early creating a more mesaticephalic type of head.
    Because the cephalic index shifts back to the left in the Bronze Age, I'd be inclined to say that this is ethnic mingling with regional natives rather than linear evolution towards brachycephaly, at least within this short time frame.

  3. "the cephalic index shifts back to the left in the Bronze Age"

    Bell Beaker is pre-Bronze, by many centuries everywhere. Unless you're meaning that it shifts to dolicocephaly (not sure what "the left" is in this context).

    In any case I insist that there are no brachys in the Basque Country (nor probably in all Iberia) before the Bronze Age and that they are usually imagined to be proto-Celtic "prospectors" of some sort. Something that comes from mainland Europe (and is in any case minoritary). No BB brachys AFAIK in the Southwest.

  4. "the cephalic index shifts back to the left in the Bronze Age"

    by this I mean that in the later metal ages average head length increases slightly, then broadens after the Middle Ages until immigration in the 1950's, then moving in the other direction.

    1. Evidently what happens in Germany is not the same what happens in Iberia, so once again there is no pan-European "Beaker folk", just pots, sites and contexts.

      Also the brachicephalization after the 50s can hardly have as root immigration (again in Germany, navel of the World!) because most immigrants were Southern Europeans who are not usually brachy, rather dolico (meso). Mesocephaly (dolicocephaly for European variation range) is classically characterstic of the Mediterraneo-Nordic arch, while brachycephaly is of the Alpino-Baltic wedge (French, Hungarians, Swiss, Russians...). I have read that all measured individuals were blooded Germans and that it has to do with unknown environmental factors such as sleeping postures in childhood or whatever.

      There's something epigenetic, not merely inherited to such things, but it's unclear what.

  5. Agree there are several factors at work including long term trends, natural variability and environmental factors. The diet of the Beakers may have also been a factor in their build. Ethnicity may be a large factor as well since Beakers are surrounded by non-Beakers everywhere with different shaped heads. But this is the enduring problem that hopefully genetics will resolve..

  6. The bottom line conclusion would seem to be that the Beakers were predominantly a distinct migratory population rather than a cultural diffusion phenomena, with or without some limited exceptions, and that the distinctiveness faded with time due to admixture and/or assimilation of environmental factors.

    1. That's correct. For most of the last 120 some odd years that has been the majority opinion based on the skeletons of Beakers and this view was independently reached in most of Europe. The question then becomes one of the size of their population which I understand was comparatively small when taking a conservative view of required paraphernalia.

  7. The problem with Bartels' analysis is that already pointed out by Brodie - the lack of early 3rd millennium BC material for comparison. Since Bartels wrote we now know from a programme of radiocarbon dating that the vast majority of the Neolithic skeletons she used for her study date to 3800-3600 BC, so the gap between her two sample populations is 1100-1800 years. As a result I do not see that a comparison can really tell us much.

    1. Thanks for pointing this out, I'll look for Neil Brodie's comments.
      I think in that case Bartels analysis broadly tells that there was a population turnover between the EN and the BA, which corroborates the genetic evidence (only in the continent thus far), but lacks the precision to tackle the Beaker Problem effectively.

      I will be very interested in the genetic profiles immediately preceding the Beaker phenomenon in the Isles. It may offer a unique opportunity to study migration events.