Understanding how spatially variable selection shapes adaptation is an area of long-standing interest in evolutionary ecology. Recent meta-analyses have quantified the extent of local adaptation, but the relative importance of abiotic and biotic factors in driving population divergence remains poorly understood. To address this gap, we combined a quantitative meta-analysis and a qualitative metasynthesis to (1) quantify the magnitude of local adaptation to abiotic and biotic factors and (2) characterize major themes that influence the motivation and design of experiments that seek to test for local adaptation. Using local-foreign contrasts as a metric of local adaptation (or maladaptation), we found that local adaptation was greater in the presence than in the absence of a biotic interactor, especially for plants. We also found that biotic environments had stronger effects on fitness than abiotic environments when ignoring whether those environments were local versus foreign. Finally, biotic effects were stronger at low latitudes, and abiotic effects were stronger at high latitudes. Our qualitative analysis revealed that the lens through which local adaptation has been examined differs for abiotic and biotic factors. It also revealed biases in the design and implementation of experiments that make quantitative results challenging to interpret and provided directions for future research.
Bibliographical noteFunding Information:
We thank the Community Genetics Discussion Group at the University of Minnesota, especially Ruth Shaw and Georgiana May, for lively discussion that helped begin this project; Chris Caruso for insightful comments on an early version of the manuscript; and Derek Nedveck for assistance collecting articles for the data set. The National Science Foundation provided generous support for R.D.B.R. and D.A.M. (DEB-1025004 and DEB-1255141) and for J.B.Y. and P.T. (IOS-1237993 and IOS-1724993), and the National Sciences and Engineering Research Council of Canada provided support for A.J.G. via the Alexander Graham Bell Graduate Scholarship. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
© 2020 by The University of Chicago.
- Latitudinal gradient
- Life history
- Natural selection
- Reciprocal transplant
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.