Pleistocene stickleback genomes reveal the constraints on parallel evolution

• DOI: 10.1101/2020.08.12.248427
• Publication Date: 2020-08-13T13:05:12Z
• Authors: Melanie Kirch; Anders Romundset; M. Thomas P. Gilbert; Felicity C. Jones; Andrew D. Foote
• Keywords: Parallel evolution; Adaptive Evolution; Fjord

Parallel evolution is typically studied by comparing modern populations from contrasting environments, therefore the chronology of adaptive changes remains poorly understood. We applied a paleogenomics approach to investigate this temporal component adaptation sequencing genomes 11-13,000-year-old stickleback recovered transitionary layer between marine and freshwater sediments two Norwegian isolation lakes, them with 30 same lakes adjacent fjord. The ancient shared genome-wide ancestry fjord population, whereas lake have lost substantial ancestral variation following founder effects. found had freshwater-adaptive alleles in genomes, showed incomplete adaptation, revealing hitherto underappreciated stochastic nature selection on standing present populations. One Sentence Summary ‘Pleistocene threespine reveal insights into earliest stages adaptation’