Looking for signatures of sex-specific demography and local adaptation on the X chromosome

A genome-wide study of X chromosome genetic diversity in human populations shows the impact of social organization and local adaptation

Transmission of Migration Propensity Increases Genetic Divergence Between Populations

The advent of molecular genetics has brought invaluable information, which is now routinely used by anthropologists in their attempt to reconstruct our demographic past. Since the mitochondrial DNA loci are much more similar between populations than are the Y chromosome loci, it has been suggested that women had a much higher migration rate than men throughout history. Based on an examination of intergenerational migration patterns in three large demographic databases, we bring this inference into question. In some early Canadian settlements (St. Lawrence Valley and Saguenay), and in the past Krummhörn region of Northwest Germany, men whose father was a migrant were more likely to migrate, while the migration probability of women was largely independent of that of their mothers. As a result, men’s movements were less effective in preventing genetic differentiation between populations than women’s movements. If it is largely prevalent among human societies, this male-specific transmission of migration propensity could partly explain the geographical clustering of Y chromosome distributions. In order to account for its impact, we propose a slight modification of Wright’s Island model. We also address the relevance of this model with respect to previously reported measures of population differentiation and we discuss the supporting historical and anthropological literature. We conclude that the widespread patrilocal rules of post-marital residence have generated both a higher female migration rate and a patrilineal dependency in the propensity to migrate

Matrilineal Fertility Inheritance Detected in Hunter–Gatherer Populations Using the Imbalance of Gene Genealogies

Fertility inheritance, a phenomenon in which an individual's number of offspring is positively correlated with his or her number of siblings, is a cultural process that can have a strong impact on genetic diversity. Until now, fertility inheritance has been detected primarily using genealogical databases. In this study, we develop a new method to infer fertility inheritance from genetic data in human populations. The method is based on the reconstruction of the gene genealogy of a sample of sequences from a given population and on the computation of the degree of imbalance in this genealogy. We show indeed that this level of imbalance increases with the level of fertility inheritance, and that other phenomena such as hidden population structure are unlikely to generate a signal of imbalance in the genealogy that would be confounded with fertility inheritance. By applying our method to mtDNA samples from 37 human populations, we show that matrilineal fertility inheritance is more frequent in hunter–gatherer populations than in food-producer populations. One possible explanation for this result is that in hunter–gatherer populations, individuals belonging to large kin networks may benefit from stronger social support and may be more likely to have a large number of offspring

Continuité génétique des populations anciennes et récentes d’Asie Centrale

Depuis la préhistoire, l’Asie centrale méridionale est une région au carrefour des mouvements de populations, de cultures et de marchandises. Aujourd’hui l’Asie Centrale est peuplée par des populations réparties dans deux groupes culturels et linguistiques : le groupe Indo-iranien et le groupe Turco-mongol. L’établissement d’une base de données génétiques sur ces populations a permis d’étudier leur structure génétique en mettant en évidence la migration de populations d’Asie de l’est à l’orig..

beDNA : un projet visant à la collection systématique d’échantillons humains archéologiques à vocation paléogénétique – une première expérimentation

La paléogénétique occupe désormais une place importante dans les problématiques archéologiques. Toutefois, les analyses d’ADN ancien peuvent être desservies, voire empêchées, par l’état de préservation des échantillons en raison de contamination par de l’ADN moderne ou de mauvaises conditions de stockage. Le projet beDNA, "banque d’échantillons et de Données Nationale Archéogénétique", souhaite donner les moyens d’analyses paléogénétiques futures, en proposant le stockage systématique d’échantillons des squelettes humains tenant compte des contraintes inhérentes à la préservation de l’ADN ancien. Le projet implique (1) un protocole systématique d’échantillonnage "propre" des restes humains sur le terrain commun à toutes les opérations archéologiques, (2) un espace de stockage dédié à ces échantillons adapté à la conservation de l’ADN ancien, (3) une base de données faisant le lien entre les sites et les échantillons conservés dans la banque, (4) l’approbation par l’État des demandes d’analyse d’échantillons après expertise. La phase de test du projet, initiée en septembre 2020 sur la région Île-de-France, nous a permis d’évaluer et d’ajuster le protocole d’échantillonnage sur le terrain et les dispositifs de transfert vers la banque. Cette note présente les étapes envisagées pour chaque échantillon, depuis les terrains jusqu’aux laboratoires d’analyse génétique, ainsi que le déroulement de sa phase test, en cours, et les premiers retours d’expérience.Palaeogenetics is becoming increasingly important in tackling archaeological issues. However, analyses of ancient DNA can be hampered or even prevented by the state of preservation of samples due to poor storage conditions, and because of contamination by modern DNA. The beDNA project for a national archaeological genetic data and sample bank (banque d’échantillons et de Données Nationale Archéogénétique) is developing the means to enable future palaeogenetic analyses by systematically storing human skeletal samples, with the constraints inherent to the preservation of ancient DNA taken into account. This project comprises (1) a systematic protocol for "clean" sampling of human remains to be common to all archaeological operations, (2) a dedicated storage space for samples, suited to aDNA preservation, (3) a database linking sites with the samples stored in the bank, (4) approval of sample analysis requests by authorities, after expert review. The test phase of the project, which began in September 2020 in the Île-de-France region, enabled us to evaluate and adjust both the sampling protocol in the field and the transfer process to the beDNA bank. This note describes the different stages envisaged for each sample, from the archaeological field to the genetics laboratory, as well as the development of the experimental phase and initial feedback from it

Interview with Laura Fortunato, Winner of the 2011 Gabriel W. Lasker Prize

An international jury composed of Michael Crawford (University of Kansas, USA), Dennis O\u27Rourke (University of Utah, USA), and Stephen Shennan (University College London, UK) has awarded the Gabriel Ward Lasker Prize 2011 to Dr. Laura Fortunato for her articles entitled Reconstructing the History of Residence Strategies in Indo-European–Speaking Societies and Reconstructing the History of Marriage Strategies in Indo-European–Speaking Societies considered as the best contribution to the 83rd volume of Human Biology (2011). Laura Fortunato is an Omidyar Fellow at the Santa Fe Institute in Santa Fe, New Mexico. She received her Ph.D. in anthropology from University College London in 2009; her doctoral research focused on the evolution of kinship and marriage systems. In particular, she has investigated the evolution of marriage strategies, wealth transfers at marriage, residence strategies, and inheritance strategies. Laura\u27s current research activities apply conceptual and methodological tools developed in evolutionary biology to a diverse range of topics in anthropology, from matrilineal kinship organization to cultural evolution

Genetic diversity and the emergence of ethnic groups in Central Asia

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

The epigenomic landscape of African rainforest hunter-gatherers and farmers

International audienceThe genetic history of African populations is increasingly well documented, yet their patterns of epigenomic variation remain uncharacterized. Moreover, the relative impacts of DNA sequence variation and temporal changes in lifestyle and habitat on the human epigenome remain unknown. Here we generate genome-wide genotype and DNA methylation profiles for 362 rainforest hunter-gatherers and sedentary farmers. We find that the current habitat and historical lifestyle of a population have similarly critical impacts on the methylome, but the biological functions affected strongly differ. Specifically, methylation variation associated with recent changes in habitat mostly concerns immune and cellular functions, whereas that associated with historical lifestyle affects developmental processes. Furthermore, methylation variation—particularly that correlated with historical lifestyle—shows strong associations with nearby genetic variants that, moreover, are enriched in signals of natural selection. Our work provides new insight into the genetic and environmental factors affecting the epigenomic landscape of human populations over time