--- _id: '564' abstract: - lang: eng text: "Maladapted individuals can only colonise a new habitat if they can evolve a\r\npositive growth rate fast enough to avoid extinction, a process known as evolutionary\r\nrescue. We treat log fitness at low density in the new habitat as a\r\nsingle polygenic trait and thus use the infinitesimal model to follow the evolution\r\nof the growth rate; this assumes that the trait values of offspring of a\r\nsexual union are normally distributed around the mean of the parents’ trait\r\nvalues, with variance that depends only on the parents’ relatedness. The\r\nprobability that a single migrant can establish depends on just two parameters:\r\nthe mean and genetic variance of the trait in the source population.\r\nThe chance of success becomes small if migrants come from a population\r\nwith mean growth rate in the new habitat more than a few standard deviations\r\nbelow zero; this chance depends roughly equally on the probability\r\nthat the initial founder is unusually fit, and on the subsequent increase in\r\ngrowth rate of its offspring as a result of selection. The loss of genetic variation\r\nduring the founding event is substantial, but highly variable. With\r\ncontinued migration at rate M, establishment is inevitable; when migration\r\nis rare, the expected time to establishment decreases inversely with M.\r\nHowever, above a threshold migration rate, the population may be trapped\r\nin a ‘sink’ state, in which adaptation is held back by gene flow; above this\r\nthreshold, the expected time to establishment increases exponentially with M. This threshold behaviour is captured by a deterministic approximation,\r\nwhich assumes a Gaussian distribution of the trait in the founder population\r\nwith mean and variance evolving deterministically. By assuming a constant\r\ngenetic variance, we also develop a diffusion approximation for the joint distribution\r\nof population size and trait mean, which extends to include stabilising\r\nselection and density regulation. Divergence of the population from its\r\nancestors causes partial reproductive isolation, which we measure through\r\nthe reproductive value of migrants into the newly established population." article_processing_charge: No article_type: original author: - first_name: Nicholas H full_name: Barton, Nicholas H id: 4880FE40-F248-11E8-B48F-1D18A9856A87 last_name: Barton orcid: 0000-0002-8548-5240 - first_name: Alison full_name: Etheridge, Alison last_name: Etheridge citation: ama: Barton NH, Etheridge A. Establishment in a new habitat by polygenic adaptation. Theoretical Population Biology. 2018;122(7):110-127. doi:10.1016/j.tpb.2017.11.007 apa: Barton, N. H., & Etheridge, A. (2018). Establishment in a new habitat by polygenic adaptation. Theoretical Population Biology. Academic Press. https://doi.org/10.1016/j.tpb.2017.11.007 chicago: Barton, Nicholas H, and Alison Etheridge. “Establishment in a New Habitat by Polygenic Adaptation.” Theoretical Population Biology. Academic Press, 2018. https://doi.org/10.1016/j.tpb.2017.11.007. ieee: N. H. Barton and A. Etheridge, “Establishment in a new habitat by polygenic adaptation,” Theoretical Population Biology, vol. 122, no. 7. Academic Press, pp. 110–127, 2018. ista: Barton NH, Etheridge A. 2018. Establishment in a new habitat by polygenic adaptation. Theoretical Population Biology. 122(7), 110–127. mla: Barton, Nicholas H., and Alison Etheridge. “Establishment in a New Habitat by Polygenic Adaptation.” Theoretical Population Biology, vol. 122, no. 7, Academic Press, 2018, pp. 110–27, doi:10.1016/j.tpb.2017.11.007. short: N.H. Barton, A. Etheridge, Theoretical Population Biology 122 (2018) 110–127. date_created: 2018-12-11T11:47:12Z date_published: 2018-07-01T00:00:00Z date_updated: 2023-09-11T13:41:22Z day: '01' ddc: - '519' - '576' department: - _id: NiBa doi: 10.1016/j.tpb.2017.11.007 ec_funded: 1 external_id: isi: - '000440392900014' file: - access_level: open_access checksum: 0b96f6db47e3e91b5e7d103b847c239d content_type: application/pdf creator: nbarton date_created: 2019-12-21T09:36:39Z date_updated: 2020-07-14T12:47:09Z file_id: '7199' file_name: bartonetheridge.pdf file_size: 2287682 relation: main_file file_date_updated: 2020-07-14T12:47:09Z has_accepted_license: '1' intvolume: ' 122' isi: 1 issue: '7' language: - iso: eng license: https://creativecommons.org/licenses/by-nc/4.0/ month: '07' oa: 1 oa_version: Submitted Version page: 110-127 project: - _id: 25B07788-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '250152' name: Limits to selection in biology and in evolutionary computation publication: Theoretical Population Biology publication_status: published publisher: Academic Press publist_id: '7250' quality_controlled: '1' related_material: record: - id: '9842' relation: research_data status: public scopus_import: '1' status: public title: Establishment in a new habitat by polygenic adaptation tmp: image: /images/cc_by_nc.png legal_code_url: https://creativecommons.org/licenses/by-nc/4.0/legalcode name: Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) short: CC BY-NC (4.0) type: journal_article user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 122 year: '2018' ...