Sex-specific demographic behaviours that shape human genomic variation.

Area of Science:

• Human evolutionary genetics
• Population genomics
• Anthropology

Background:

• Contrasting diversity patterns exist between mitochondrial DNA (mtDNA) and Y chromosome genetic systems in humans.
• Previous hypotheses attribute these differences to sex-specific behaviors, particularly migration rates between males and females.

Purpose of the Study:

• To reassess the influence of sex-specific behaviors on human genomic variation using high-density genomic data.
• To compare genetic patterns across autosomal, sex-linked, and uniparental genetic systems at global and local scales.

Main Methods:

• Review of studies comparing genetic patterns in uniparental (mtDNA, Y chromosome) and biparental (autosomal) genetic systems.
• Analysis of genomic data to evaluate the role of sex-specific migration rates in explaining observed genetic diversity differences.
• Exploration of anthropological factors contributing to sex-specific effective population sizes.

Main Results:

• Differences in male and female migration rates contribute to contrasting genetic diversity patterns but are not the sole explanation.
• Sex-specific differences in effective population size are also significant factors influencing human genomic variation.
• Anthropological processes such as variance in reproductive success (e.g., polygyny), descent rules, and transmission of reproductive success likely drive these effective population size differences.

Conclusions:

• Sex-specific migration rates and effective population sizes, shaped by anthropological factors, are crucial for understanding human genomic variation.
• A comprehensive understanding requires considering both demographic processes and cultural/behavioral influences on reproduction and lineage.