As anatomically modern humans migrated from sub-Saharan Africa approximately 100 k years ago, they encountered a wide range of different and new environmental conditions, which may have imposed a selective pressure. The observed variation in phenotypes among human populations is indeed partly explained by humans adapted to different environments.
In line with this idea, genome-wide scans for signatures of natural selection identified genes involved in skin pigmentation, to module the different need for protection in areas with different UV radiation exposure. Similarly genes associated with metabolic process and infectious disease resistance have been often targeted by natural selection, in response to adaptation to different diet regimes and pathogen intensity.
UCL has substantial experience in detecting genetic adaptation in human genomes.