Summary of the 2014 ESHE Meeting

florenceThe 4th annual meeting of the European Society for the study of Human Evolution (ESHE) took place in Florence, Italy (Sep 18th-20th). This is one of the top conferences we can see in Europe for this field.

Below is a summary of a selection of topics presented in the meeting.

Arsuaga, Juan Luis:

Hominins from Sima de los Huesos site in Atapuerca are 430 KY old. Most of the other European Middle Pleistocene fossils are apparently younger, including specimens that look more primitive than Sima. If the ancestral stem group of neandertal & sapiens survived after the Neandertal lineage branched off, then a primitive morphology could still be found in fossils that are younger than the derived ones. Current age of Petralona is clearly underestimated. Arago is a bit older and more primitive than Sima.

Bayle, Priscilla et al:

A new Neandertal mandible was discovered (2013) in Sirogne Cave (France). The minimum number of individuals found in that cave is four.

Benazzi, Stefano et al:

Taurodontism is a condition found in the molar teeth whereby the body of the tooth and pulp chamber is enlarged vertically at the expense of the roots. This affects to 1% of modern humans but is quite frequent in Neandertals, due to three possible hypothesis: biomechanical advantage, adaptation to a high attrition diet, genetic drift effects. Finite Element Analysis modelling to the Le Moustier 1 specimen was run to test the first hypothesis, showing that enlarged pulpar chambers do not modify the biomechanical properties of the molars. 

Coolidge, Frederick:

Specific higher cognitive functions relate to the recent expansion of the parietal lobes in modern humans vs. Neandertals and H. heidelbergensis: working memory, abstraction, egocentric memory, episodic memory, sense of self, etc.

Di Maida, Gianpiero et al:

New engravings (representing aurochs) were recently found at Grotta di Cala die Genovesi (Sicily, Italy), showing a dominance of bovids corresponding to the ice age of Late Glacial to early Holocene in that area.

Gunz, Philipp et al:

In the evolutionary history of H. sapiens, changes or cranial size have therefore shaped many aspects of cranial morphology. The Late Pleistocene Hofmeyr skull from South Africa is one of the few modern skulls discovered in Africa south of Ethiopia and older than 20,000 years (dated 37,000 years).  This skull is as typical of the population from which the Eurasian Upper Paleolithic modern humans descended.

Among modern humans, Hofmeyr is closest to the gracile South Africa Khoe-San. Present-day Khoe-San people display a gracilized version of the ancestral modern human cranial morphology. Khoe-San has been identified as the oldest modern human group living today.

Harvati, Katerina and Reyes-Centeno, Hugo:

The timing and geographical pattern of the out-of-Africa event is a never-ending debate.

The decreasing genetic and phenotypic diversity of extant humans at increasing distances from sub-Saharian Africa suggests a single Late Pleistocene dispersal with a series of founder effects during a rapid worldwide expansion out of Africa.

Recent genetic studies plus archeologic evidence suggest instead a southern route dispersal into Asia in the late Middle Pleistocene, followed by a separate dispersal into northern Eurasia.

Both genomic and craniometric support a multiple dispersals model, in which Australo-Melanesian populations are relatively isolated descendants of an early dispersal, whereas other Asian populations are descended from a subsequent migration event. Genetic divergence between South Africans and Melanesians is estimated in 116,000 years ago.

Kitagawa, Keiko et al:

In the Swabian Jura (Germany), the transition from Middle to Upper Paleolithic coincides with a decline of the carnivores presence. The study of faunal remains suggests a difference in the subsistence behavior of Neandertals and modern humans, which was driven mainly not by cognitive abilities but changes in the climate and local abundance of prey.

Le Cabec, Adeline et al:

Dental development pattern of the Australopithecus sediba juvenile MH1 were assessed by synchrotron imaging, suggesting an age of 10.5-11.5 years, earlier than the expected 12-13 years like if it had followed modern human development patterns.

Macho, Gabriele:

Except for Ardipithecus, body size sexual dimorphism is generally marked in early hominins. The brain size increase in Australopithecus, albeit small, is consistent with proportions of a pleiotropic effect resulting from selection for larger-bodied males, probably in response to the habitat becoming increasingly open.

Manzi, Giorgio et al:

An almost complete frontal bone of Neandertal morphology was recently found in the Po Valley, Italy. It was  probably carried by the current from upstream Middle-Late Pleistocene deposits.

Neubauer, Simon et al:

Functional brain lateralization is the specialization of brain areas in different hemispheres, related to brain asymmetries, for example humans have a larger left Broca’s cap region (linked to language) than the right. Unexpectedly, a geometric morphometric analysis on large samples shows that the brain is more asymmetrical in gorillas than in humans, they have the most asymmetric endocasts.

Posth, Cosimo et al:

Mitochondrial DNA suggests genetic continuity between Upper Paleolithic and Mesolithic hunter-gatherers in Europe, followed by an almost complete replacement with limited genetic admixture by Neolithic farmers. Environmental changes in the late Pleistocene such as the Last Glacial Maximum (24-16,000 years BP) could have influenced migrations pattern and changed the genetic population structure. mtDNA suggests a bottleneck between the Magdalenian and Mesolithic.

Richmond, Brian et al:

A series of excavations between 2010-14 in Ileret, Kenya showed 1.5 MYA hominin footprints. These are much more abundant than skeletodental remains, suggesting they spent more time near-water than expected. They show body mass and stature comparable to predicted sizes of male Homo ergaster or Paranthropus boisei. This suggest the footprints were likely left by groups of males patrolling or hunting near-water bodies.

Roussel, Morgan and Soressi, Marie:

The relationship of Châtelperronian with the early phases of the Aurignacian have been recently revaluated. Retouched Châtelperronian bladelets from Les Cottés (France) are evidence of contact between Châtelperronian and the Protoaurignacian with roots in the local Mousterian.

Ruebens, Karen et al:

Backed knives production relates the Châtelperronian to older Mousterian (Mousterian of Acheulean Tradicion, MTA) made by Neandertals in the same French region. The same Neandertal groups made the discoidal-denticulate Mousterian and MTA in the geography domain of the later Châtelperronian.

Stoessel, Alexander:

Due to their small size, few middle ear ossicles remain in the fossil record. Recent measurements over La Ferrassie 3 specimen show that there are more difference between this Neandertal’s ear ossicles and modern humans than between those of chimps and gorillas.

Weaver, Timothy D. et al:

Patterns of cranial differentiation among modern humans are mainly influenced by neutral divergence: with isolation between groups and complete neutrality (no action of natural selection), genetic drift and mutation cause the evolutionary divergence. Cranial differentiation has been unconstrained in Neandertals and modern humans, largely under neutral evolutionary processes, while in chimpanzees it may have been more restricted by stabilizing natural selection, causing much slower morphological evolution in apes than in humans.

Zilhao, Joao et al:

Two sites in Mula, Murcia (Southern Spain) provide a sequence of 40,000 years of occupation ranging from the Mousterian to Epimagdalenian.  High resolution chronostratigraphic studies show that Neandertals were replaced by modern humans in that region only between 37 and 36,000 years BP.

Zwyns, Nicolas et al:

An open debate tries to clarify whether modern humans disperse in Asia before or after the emergence of a full-fledged Upper Paleolithic traditions, i.e. a full modern behavioral package.

The diversity of the Eurasian fossil and archaeological record suggests several routes, multiple dispersal or other mechanisms like gene flow.

Initial Upper Paleolithic likely marked modern human expansion in Eurasia reaching the Altai mountains at least 46,000 years BP.

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