The Dispersal of Homo sapiens in Europe

Nature has two papers relating to the dispersal of Homo sapiens in Europe. The first, by Higham et al provides new dates on KC4 (Kent’s Cavern), a maxilla fragment attributed to Homo sapiens. The new dates (44.2 – 41.5 kyr cal BP) make KC4 contemporary with late European Neanderthals. The Higham et al article also rexamines the morphology of KC4 and confirms that it is Homo sapiens.

Hyena Coprolites And Hominin Hair

National Geographic has an interesting story on hair found in hyena coprolites. The coprolites were in strata that date to about 195,000-257,000 years ago.

Rak and Australopithecus afarensis: A Second Look

Back in April of 2007 I wrote a brief post on a paper by Rak, Ginzberg, and Geffin. I had meant to write a more in depth post about it but kept procrastinating.

Von Economo Neurons and Hominoids

I mentioned a few weeks ago that I would have more to say about primates, brain evolution, and life history. I still plan on exploring that in future posts, but wanted to mention this interesting item that deserves a post of its own.

Chimp and Human Genome Compared and Other Interesting Evolution Stories

The chimp and human genomes are being compared in two articles that came out today.

Skull Fragments: A Frontal From Mongolia

It was published last month in C. R. Palevol 7 (2008) 51-60.

What You Can Learn From Bones: When Did We Start Wearing Shoes?

Bioarchaeologists and paleoanthropologists draw on a wide variety of methods in order to analyze bone. The exact technique depends upon the problem being addressed. One technique, associated mainly with Christopher Ruff, that has been around since the late 1970’s involves the use of beam model analysis. In beam model analysis cross sections of bone, perpendicular to the long axis, are taken and the distribution of bone is analyzed. Based on the measures derived from the analysis the mechanical properties of the bone can be determined, and this in turn can be related to locomotion, changes in subsistence strategy, sexual dimorphism, and various temporal trends (among other things). This post is concerned with the analysis of temporal trends, in particular, with the effects of shoe wearing on pedal morphology.

When Did Humans Start Wearing Shoes: A Second Look

I originally blogged about this story in August of 2005 and reposted the story (twice actually) in May of 2006. Trinkaus has recently returned to the subject and analyzed some skeletal material from Sunghir and Tianyuan. I have tracked down both articles on the subject and will have more to say as soon as I have finished reading them…

Dating the Mladec Skulls

This comes from a item in Science Daily

Mladec is an upper paleolithic site in central Europe. The material from the site was first descibed in 1925 by J. Szombathy. The site was dated to approximately 30,000-33,000 years BP based on archaeological grounds – which puts it as a contemporary of Skhul and Qafzeh. At least eight crania, some mandibles and postcrania have been discovered. Below is a picture of one of the crania (Mladec 1 if I’m not mistaken) and one of the fragments (part of a maxilla).

Mladec Crania

Mladec is important in the debate concerning the origins of anatomically modern humans. The sample displays a wide degree of morphological variability. For example, the skull above has a moderate supraorbital torus (brow ridge), small mastoids and marked posterior cranial flattening. The supraorbital torus is into central and lateral parts by a slight groove at, approximately, the middle of each orbit. Below is a picture showing some of the anatomy of the cranium for reference.

Cranial Anatomy 

Mladec 2, on the other hand, lacks a supraorbital torus, has large mastoids and the back of the cranium is higher and rounder (I should mention that Mladec 1 and 2 are both females). Both skulls are quite robust compared to later upper Paleolithic skulls. The male skulls from Mladec are somewhat archaic in appearance. They have low braincases, thick cranial bones and large supraorbitals. They do, however have small mastoids (a characteristic of anatomically modern humans). (Correction added later: small mastoids are actually a characteristic of neanderthals not anatomically modern humans).They also have a certain amount of facial prognathism – approaching that of neanderthals. The nasal aperture is broad – a neanderthal characteristic also.

Recently the Mladec material was dated directly, via radiocarbon dating. Generally, when an artifact or skeletal material is dated it is indirectly. Usually organic material – such as charcoal – that is in association with the artifact or skeleton is dated. In this case some of the teeth were radiocarbon dated (to approximately 31,000 BP). Why is this important?

The Mladeč remains are universally accepted as those of early modern humans. However, there has been an ongoing debate as to whether they exhibit also distinctive archaic features, indicative of some degree of Neandertal ancestry, or are morphologically aligned solely with recent humans and therefore document only a dispersal of modern humans into Europe.

The radiocarbon dating of the Mladeč assemblage confirms that they derived from the time period of the middle to late Aurignacian of Central Europe. Given the presence of multiple individuals, males and females, adult and immature with cranial, dental and postcranial elements, the Mladeč assemblage becomes the oldest directly dated substantial assemblage of modern human remains in Europe

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As Wolpoff (in the first edition of Paleoanthropology) puts it:

… a rather convincing case could be made for the hypothesis that the earliest modern sapiens samples represent a morphological transition between Neandertals and later sapiens populations. More recently eastern European authors…have suggested that the evolutionary sequences in this area can best be interpreted as the result of frequency changes in characteristics already present in Neandertal populations.

Essentially, Wolpoff is arguing that the kinds of things we see in other transitions – such as the dinosaur/bird or dinosaur/mammal transition also apply to human evolution. For example in the dinosaur/bird transition there were a wide variety of dinosaurs with traits that would later be characteristic of birds – but they were not all combined in one dinosaur. One could say the same about the dinosaur/mammal transition.
One of the other reasons that Mladec is important is that, as mentioned above, the skeletal material represents males, females, juveniles and adults. In other words it represents a population. Understanding populational variability will help us gain a better understanding of human evolution.