Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale.
Bibliographical noteFunding Information:
The Global Urban Evolution project was primarily funded by an NSERC Discovery Grant, Canada Research Chair and NSERC Steacie Fellowship to M.T.J.J. J.S.S. received funding from an NSERC Canadian Graduate Scholarship and C.R.F. is funded by an NSERC Postdoctoral Fellowship. P.R.P.-N., R.W.N., and J.C.C. were supported by NSERC Discovery grants. M.A. was funded by NSF RCN DEB-1840663. F.A. received funding from CAPES. M.T.K.A. was funded by CONICYT PIA APOYO CCTE AFB170008. J.R.B, T.C.L., and S.A.S were supported by Monmouth University School of Science Summer Research Program. E.G. was funded by Département de Biologie, Université de Moncton. C.G.-L. received funding from the Center of Applied Ecology and Sustainability (CAPES), and ANID PIA/BASAL FB0002. S.G. was funded by the Max Planck Society. P.J.-A. was funded by ANID PIA/BASAL FB210006. I.N. and M.S. were supported by Leiden Municipality. K.M.O. was funded by US NSF awards IOS-1557770 and DEB-1601641. J.C.P. thanks FAPESP process 2018/00107-3 and M.C.R. thanks CNPq and FAPESP.
© 2022 American Association for the Advancement of Science. All rights reserved.
Copyright 2022 Elsevier B.V., All rights reserved.