Evaluating demographic models for goat domestication using mtDNA sequences

Routes of migration and exchange are important factors in the debate about how the Neolithic transition spread into Europe. Studying the genetic diversity of livestock can help in tracing back some of these past events. Notably, domestic goat (Capra hircus) did not have any wild progenitors (Capra aegagrus) in Europe before their arrival from the Near East. Studies of mitochondrial DNA have shown that the diversity in European domesticated goats is a subset of that in the wild, underlining the ancestral relationship between both populations. Additionally, an ancient DNA study on Neolithic goat remains has indicated that a high level of genetic diversity was already present early in the Neolithic in northwestern Mediterranean sites. We used coalescent simulations and approximate Bayesian computation, conditioned on patterns of modern and ancient mitochondrial DNA diversity in domesticated and wild goats, to test a series of simplified models of the goat domestication process. Specifically, we ask if domestic goats descend from populations that were distinct prior to domestication. Although the models we present require further analyses, preliminary results indicate that wild and domestic goats are more likely to descend from a single ancestral wild population that was managed 11,500 years before present, and that serial founding events characterise the spread of Capra hircus into Europe.

An analysis of bimanual actions in natural feeding of semi-wild chimpanzees

Objective The objective of the current study was to investigate the lateral dominance for a bimanually coordinated natural feeding behavior in semi-wild chimpanzees. Materials and Methods We investigated strychnos spp. fruit consumption behaviors in semi-wild chimpanzees as an ecologically comparable feeding behavior to those found in cerebral lateralization studies of non-primate species. Video recordings of thirty-three chimpanzees were assessed while they consumed hard-shelled strychnos fruits. We explored statistical and descriptive measures of hand dominance to highlight lateralized patterns. Results Statistical evaluation of feeding bouts revealed a group-level right-handed bias for bimanual coordinated feeding actions, however few individuals were statistically lateralized. Descriptive analyses revealed that the majority of individuals were lateralized and possessed a right-handed bias for strychnos feeding behavior. Discussion The results provide empirical evidence in supports of an early evolutionary delineation of function for the right and left hemispheres. The present findings suggest that great apes express an intermediate stage along the phylogenetic trajectory of human manual lateralization.