Population genomics of post-glacial western Eurasia

Area of Science:

• Paleogenomics
• Human Evolution
• Population Genetics

Background:

• Western Eurasia experienced significant human migrations throughout the Holocene.
• Understanding the genetic impact of these movements is crucial for reconstructing population history.

Purpose of the Study:

• To investigate the cross-continental genetic effects of Holocene human migrations in Eurasia.
• To analyze ancient genomes from Mesolithic and Neolithic periods to identify population dynamics.

Main Methods:

• Shotgun sequencing of 317 ancient genomes from northern and western Eurasia.
• Imputation with published data to generate over 1,600 diploid genotypes.
• Analysis of genomic data to identify ancestry shifts and relatedness patterns.

Main Results:

• A 'great divide' genomic boundary was identified between the Black Sea and the Baltic.
• Mesolithic populations were genetically distinct east and west of this boundary.
• Neolithization led to substantial ancestry replacement in the west but not the east.
• Yamnaya-related ancestry spread around 5,000 BP, causing a second major population turnover across Eurasia.
• Hunter-gatherers from the Middle Don region contributed ancestry to the Yamnaya.

Conclusions:

• Prehistoric migrations profoundly and lastingly impacted Eurasian genetic diversity.
• The Yamnaya expansion played a key role in reshaping the genetic landscape of Western Eurasia.
• Distinct Mesolithic populations and differential responses to Neolithization shaped early Eurasian genetic structure.