The current distribution of Bantu languages is commonly considered to be a consequence of a relatively recent population expansion (3-5kya) in Central Western Africa. While there is a substantial consensus regarding the centre of origin of Bantu languages (the Benue River Valley, between South East Nigeria and Western Cameroon), the identification of the area from where the population expansion actually started, the relation between the processes leading to the spread of languages and peoples and the relevance of local migratory events remain controversial. In order to shed new light on these aspects, we studied Y chromosome variation in a broad dataset of populations encompassing Nigeria, Cameroon, Gabon and Congo. Our results evidence an evolutionary scenario which is more complex than had been previously thought, pointing to a marked differentiation of Cameroonian populations from the rest of the dataset. In fact, in contrast with the current view of Bantu speakers as a homogeneous group of populations, we observed an unexpectedly high level of interpopulation genetic heterogeneity and highlighted previously undetected diversity for lineages associated with the diffusion of Bantu languages (E1b1a (M2) sub-branches). We also detected substantial differences in local demographic histories, which concord with the hypotheses regarding an early diffusion of Bantu languages into the forest area and a subsequent demographic expansion and migration towards eastern and western Africa.

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Background: This research investigated the knowledge of the complex concept of evolution in a sample (n=1108) of final-year high school students of Rome. Particular attention was given to the evolution of Homo sapiens and to human diversity at the biological and cultural level. Obtained results were analysed in relation to the socio-cultural context of the students. The final objective of the research is to provide teachers, curriculum developers and policy makers with results on basic knowledge on evolution and human diversity of students who are to face the University. Methods: The research was conducted using an ad hoc questionnaire in five scientific (Liceo scientifico) and four humanistic (Liceo classico) high schools of Rome. The research involved the final-year students, those who are supposed to have a global basic knowledge of cultural and biological aspects of the evolutionary theory. The research project, its aims and modes of realisation were presented and discussed in detail with Deans, teachers and students of the Institutions that volunteered to participate. Results: The results show: (1) good knowledge and substantial acceptance of the evolutionary perspective; (2) that cultural and biological diversity are considered as decisive factors in modelling the present-day differences between human groups; (3) that, nonetheless, more than half the students still hold to a classificatory conception of human populations; (4) that the family cultural background is significantly relevant in the education of children.

BackgroundWhen studying the genetic structure of human populations, the role of cultural factors may be difficult to ascertain due to a lack of formal models. Linguistic diversity is a typical example of such a situation. Patrilocality, on the other hand, can be integrated into a biological framework, allowing the formulation of explicit working hypotheses. The present study is based on the assumption that patrilocal traditions make the hypervariable region I of the mtDNA a valuable tool for the exploration of migratory dynamics, offering the opportunity to explore the relationships between genetic and linguistic diversity. We studied 85 Niger-Congo-speaking patrilocal populations that cover regions from Senegal to Central African Republic. A total of 4175 individuals were included in the study.ResultsBy combining a multivariate analysis aimed at investigating the population genetic structure, with a Bayesian approach used to test models and extent of migration, we were able to detect a stepping-stone migration model as the best descriptor of gene flow across the region, with the main discontinuities corresponding to forested areas.ConclusionsOur analyses highlight an aspect of the influence of habitat variation on human genetic diversity that has yet to be understood. Rather than depending simply on geographic linear distances, patterns of female genetic variation vary substantially between savannah and rainforest environments. Our findings may be explained by the effects of recent gene flow constrained by environmental factors, which superimposes on a background shaped by pre-agricultural peopling.

The introduced European parasitoid Peristenus digoneutis is a key biocontrol agent of lygus bug pests in agricultural crops in the Northeastern USA. Changes in cultural practices and reduction of alfalfa culture have significantly reduced its abundance in its native range from historic levels. Of 48 microsatellite loci isolated from P. digoneutis genome using 454 pyrosequencing, 24 were retained based upon consistent amplification. Sixteen loci exhibited polymorphism in populations sampled in France and the USA. The number of alleles ranged from 2 to 9. The observed heterozygosity (H (o)) and the expected heterozygosity (H (e)) varied from 0.043 to 0.710 and from 0.103 to 0.728, respectively. Most loci conformed to Hardy-Weinberg equilibrium with the exclusion of five loci. These polymorphic loci will be valuable for population genetic studies and genetic conservation for P. digoneutis