Contrasting the effects of natural selection, genetic drift and gene flow on urban evolution in white clover (Trifolium repens).

ABSTRACT: Urbanization is a global phenomenon with profound effects on the ecology and evolution of organisms. We examined the relative roles of natural selection, genetic drift and gene flow in influencing the evolution of white clover (Trifolium repens), which thrives in urban and rural areas. Trifolium repens exhibits a Mendelian polymorphism for the production of hydrogen cyanide (HCN), a potent antiherbivore defence. We quantified the relative frequency of HCN in 490 populations sampled along urban-rural transects in 20 cities. We also characterized genetic variation within 120 populations in eight cities using 16 microsatellite loci. HCN frequency increased by 0.6% for every kilometre from an urban centre, and the strength of this relationship did not significantly vary between c

SUBMITTER: Johnson MTJ 

PROVIDER: S-EPMC6083247 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature