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Rudman SM, Greenblum SI, Rajpurohit S, Betancourt NJ, Hanna J, Tilk S, Yokoyama T, Petrov DA, Schmidt P. Direct observation of adaptive tracking on ecological time scales in Drosophila. Science 2022; 375:eabj7484. [PMID: 35298245 PMCID: PMC10684103 DOI: 10.1126/science.abj7484] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Direct observation of evolution in response to natural environmental change can resolve fundamental questions about adaptation, including its pace, temporal dynamics, and underlying phenotypic and genomic architecture. We tracked the evolution of fitness-associated phenotypes and allele frequencies genome-wide in 10 replicate field populations of Drosophila melanogaster over 10 generations from summer to late fall. Adaptation was evident over each sampling interval (one to four generations), with exceptionally rapid phenotypic adaptation and large allele frequency shifts at many independent loci. The direction and basis of the adaptive response shifted repeatedly over time, consistent with the action of strong and rapidly fluctuating selection. Overall, we found clear phenotypic and genomic evidence of adaptive tracking occurring contemporaneously with environmental change, thus demonstrating the temporally dynamic nature of adaptation.
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Affiliation(s)
- Seth M. Rudman
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
- School of Biological Sciences, Washington State University, Vancouver, WA 98686, USA
| | - Sharon I. Greenblum
- Department of Biology, Stanford University, Stanford, CA 94305, USA
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Subhash Rajpurohit
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Biological and Life Sciences, Ahmedabad University, Ahmedabad 380009, GJ, India
| | | | - Jinjoo Hanna
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Susanne Tilk
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Tuya Yokoyama
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Dmitri A. Petrov
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Paul Schmidt
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
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Hartfield M, Poulsen NA, Guldbrandtsen B, Bataillon T. Using singleton densities to detect recent selection in Bos taurus. Evol Lett 2021; 5:595-606. [PMID: 34917399 PMCID: PMC8645200 DOI: 10.1002/evl3.263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 10/07/2021] [Accepted: 10/08/2021] [Indexed: 11/05/2022] Open
Abstract
Many quantitative traits are subject to polygenic selection, where several genomic regions undergo small, simultaneous changes in allele frequency that collectively alter a phenotype. The widespread availability of genome data, along with novel statistical techniques, has made it easier to detect these changes. We apply one such method, the "Singleton Density Score" (SDS), to the Holstein breed of Bos taurus to detect recent selection (arising up to around 740 years ago). We identify several genes as candidates for targets of recent selection, including some relating to cell regulation, catabolic processes, neural-cell adhesion and immunity. We do not find strong evidence that three traits that are important to humans-milk protein content, milk fat content, and stature-have been subject to directional selection. Simulations demonstrate that because B. taurus recently experienced a population bottleneck, singletons are depleted so the power of SDS methods is reduced. These results inform on which genes underlie recent genetic change in B. taurus, while providing information on how polygenic selection can be best investigated in future studies.
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Affiliation(s)
- Matthew Hartfield
- Bioinformatics Research CentreAarhus UniversityAarhusDK‐8000Denmark
- Institute of Evolutionary BiologyUniversity of EdinburghEdinburghEH9 3FLUnited Kingdom
| | | | - Bernt Guldbrandtsen
- Center for Quantitative Genetics and Genomics, Department of Molecular Biology and GeneticsAarhus UniversityTjeleDK‐8830Denmark
- Rheinische Friedrich‐Wilhelms‐Universität BonnInstitut für TierwissenschaftenBonnDE‐53115Germany
- Department of Veterinary SciencesCopenhagen UniversityFrederiksberg CDK‐1870Denmark
| | - Thomas Bataillon
- Bioinformatics Research CentreAarhus UniversityAarhusDK‐8000Denmark
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