Global urban signatures of phenotypic change in animal and plant populations

Marina Alberti; Cristian Correa; John M. Marzluff; Andrew P. Hendry; Eric P. Palkovacs; Kiyoko M. Gotanda; Victoria M. Hunt; Travis M. Apgar; Yuyu Zhou

doi:10.1073/pnas.1606034114

Edited by Jay S. Golden, Duke University, Durham, NC, and accepted by Editorial Board Member B. L. Turner October 31, 2016 (received for review August 2, 2016)

Significance

Ecoevolutionary feedbacks on contemporary timescales were hypothesized over half a century ago, but only recently has evidence begun to emerge. The role that human activity plays in such dynamics is still unclear. Through a metaanalysis of >1,600 phenotypic changes in species across regions and ecosystem types, we examine the evidence that the rate of phenotypic change has an urban signature. Our findings indicate greater phenotypic change in urbanizing systems compared with natural and nonurban anthropogenic systems. By explicitly linking urban development to trait changes that might affect ecosystem function, we provide insights into the potential ecoevolutionary implications for maintaining ecosystem function and the sustainability of human well-being.

Abstract

Humans challenge the phenotypic, genetic, and cultural makeup of species by affecting the fitness landscapes on which they evolve. Recent studies show that cities might play a major role in contemporary evolution by accelerating phenotypic changes in wildlife, including animals, plants, fungi, and other organisms. Many studies of ecoevolutionary change have focused on anthropogenic drivers, but none of these studies has specifically examined the role that urbanization plays in ecoevolution or explicitly examined its mechanisms. This paper presents evidence on the mechanisms linking urban development patterns to rapid evolutionary changes for species that play important functional roles in communities and ecosystems. Through a metaanalysis of experimental and observational studies reporting more than 1,600 phenotypic changes in species across multiple regions, we ask whether we can discriminate an urban signature of phenotypic change beyond the established natural baselines and other anthropogenic signals. We then assess the relative impact of five types of urban disturbances including habitat modifications, biotic interactions, habitat heterogeneity, novel disturbances, and social interactions. Our study shows a clear urban signal; rates of phenotypic change are greater in urbanizing systems compared with natural and nonurban anthropogenic systems. By explicitly linking urban development to traits that affect ecosystem function, we can map potential ecoevolutionary implications of emerging patterns of urban agglomerations and uncover insights for maintaining key ecosystem functions upon which the sustainability of human well-being depends.

Footnotes

↵¹To whom correspondence should be addressed. Email: malberti{at}uw.edu.

Author contributions: M.A., C.C., J.M.M., A.P.H., E.P.P., K.M.G., and V.M.H. designed research; M.A., A.P.H., E.P.P., K.M.G., V.M.H., T.M.A., and Y.Z. performed research; C.C. analyzed data; and M.A., C.C., J.M.M., A.P.H., E.P.P., K.M.G., and V.M.H. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission. J.S.G. is a guest editor invited by the Editorial Board.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1606034114/-/DCSupplemental.

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