Evidence for recent, population-specific evolution of the human mutation rate

Area of Science:

• Human evolution
• Population genetics
• Genomics

Background:

• Human migration out of Africa led to adaptations to diverse environmental factors, including solar radiation.
• Light skin in temperate latitudes suggests adaptation to UV light, potentially impacting DNA repair mechanisms.
• Different human populations may have faced distinct selective pressures on genome integrity.

Purpose of the Study:

• To investigate evidence of recent changes in mutation rates within the human population.
• To explore potential differences in mutational spectra between European and Asian populations.
• To assess the stability of DNA replication fidelity throughout human evolutionary history.

Main Methods:

• Analysis of single nucleotide polymorphisms (SNPs) private to African, Asian, and European populations using the 1000 Genomes dataset.
• Comparison of mutation frequencies and types across different continental ancestries.
• Examination of the 5'-TCC-3' → 5'-TTC-3' transition in relation to UV exposure and melanoma mutations.

Main Results:

• A specific mutation type (5'-TCC-3' → 5'-TTC-3') has increased by 50% in the European population over the last 40,000-80,000 years.
• European private variation shows enrichment for this particular transition compared to Asian and African populations.
• The identified mutation is the most common somatic mutation in melanoma and frequently induced by UV in vitro.

Conclusions:

• DNA replication fidelity has not been constant since the emergence of modern humans.
• Recent evolutionary history may involve significant shifts in the human mutational spectrum.
• While causality is unclear, UV radiation is a potential factor influencing the observed changes in the European mutational landscape.