Parallel Evolution at the Regulatory Base-Pair Level Contributes to Mammalian Interspecific Differences in Polygenic...

Area of Science:

• Evolutionary biology
• Genetics
• Genomics

Background:

• Parallel evolution describes how different species independently evolve similar traits.
• While observed at various biological levels, its occurrence at the nucleotide level in noncoding DNA was less understood.
• Understanding nucleotide-level parallel evolution is key to explaining complex trait adaptation in mammals.

Purpose of the Study:

• To investigate the role of parallel evolution at the single nucleotide level in shaping mammalian complex traits.
• To determine if human genetic variations (SNPs) associated with traits like height and red blood cell count are predictive of these traits in other mammals.

Main Methods:

• Utilized single-nucleotide polymorphism (SNP) data from human intraspecific variation.
• Applied these data to predict trait values across 11 complex traits in other mammalian species.
• Analyzed associations between human-linked SNPs and interspecific trait variation in mammals, including primates and mice.

Main Results:

• Alleles at SNP positions linked to human height and red blood cell (RBC) count variation also correlate with these traits across mammals.
• These associations were consistent across deep mammalian evolutionary branches and within mouse strains.
• Primate body size variation was linked to primate-specific genomic elements, while RBC count involved both ancient and recent regions.

Conclusions:

• Conserved, tunable regulatory elements can be repeatedly utilized in parallel to drive evolutionary adaptation in mammals.
• Single nucleotides within noncoding regions play a significant role in parallel evolution of complex traits.
• This mechanism provides a framework for understanding how mammals adapt to diverse environments through genetic reuse.