Genetic rescue (GR) is an important tool in conservation biology for the management of highly inbred populations. However, GR comes at a potential cost: the reduction in native genomic content. The degree to which adaptive evolution for new immigrant alleles lead to complete or partial replacement of the native genome, depends on recombination rates, genome size, effective population sizes, and distributions of fitness effects. As one of the most well-studied examples of an inbred species that exchanged genetic material with a less inbred species, we use Neanderthals and humans as an example. Using simulations, we show that for parameters realistic for these species, the increase in fitness caused by GR is mirrored by an almost proportional reduction in the fraction of the native genome preserved. The main reason is that the effect of selection will be strongest in the first few generations during which time there is only little break-up, by recombination, of the immigrant chromosomes. We also show that in the presence of a strong and short-lived bottleneck with recessive mutations, GR leads to a stronger increase in fitness than in the presence of additive effects or a more prolonged bottleneck.
Genetic rescue Genetic extinction Genetic replacement Population genetic simulation Population size bottleneck Recessive mutations Inbreeding
This is a preview of subscription content, log in to check access.
Adams JR, Vucetich LM, Hedrick PW, Peterson RO, Vucetich JA (2011) Genomic sweep and potential genetic rescue during limiting environmental conditions in an isolated wolf population. Proc Royal Soc B 278:3336–3344CrossRefGoogle Scholar
Boyle EA, Li YI, Pritchard JK (2017) An expanded view of complex traits: from polygenic to omnigenic. Cell 169:1177–1186CrossRefGoogle Scholar
Eyre-Walker A, Woolfit M, Phelps T (2006) The distribution of fitness effects of new deleterious amino acid mutations in humans. Genetics 173:891–900CrossRefGoogle Scholar
Harris, K., R. Nielsen (2016) The genetic cost of Neanderthal introgression. Genetics 203:881–891.CrossRefGoogle Scholar
Hogg JT, Forbes SH, Steele BM, Luikart G (2006) Genetic rescue of an insular population of large mammals. Proc Royal Soc B 273:1491–1499CrossRefGoogle Scholar
Johnson WE, Onorato DP, Roelke ME, Land ED, Cunningham M et al (2010) Genetic restoration of the Florida panther. Science 329:1641–1645CrossRefGoogle Scholar
Juric I, Aeschbacher S, Coop G (2016) The strength of selection against Neanderthal introgression. Plos Genet 12:e1006340CrossRefGoogle Scholar
Messer, P. W. (2013) SLiM: simulating evolution with selection and linkage. Genetics 194:1037–1039CrossRefGoogle Scholar
Miller JM, Poissant J, Hogg JT, Coltman DW (2012) Genomic consequences of genetic rescue in an insular population of bighorn sheep (Ovis canadensis). Mol Ecol 21:1583–1596CrossRefGoogle Scholar
Orr HA (1996) Dobzhansky, Bateson, and the genetics of speciation. Genetics 144:1331–1335Google Scholar
Prufer K, Racimo F, Patterson N, Jay F, S Sankararaman et al (2014) The complete genome sequence of a Neanderthal from the Altai mountains. Nature 505:43–49CrossRefGoogle Scholar
Simons YB, Bullaughey K, Hudson RR, Sella G (2018) A population genetic interpretation of GWAS findings for human quantitative traits. PLoS Biol 16:e2002985CrossRefGoogle Scholar
Whiteley AR, Fitzpatrick SW, Funk WC, Tallmon DA (2015) Genetic rescue to the rescue. Trends Ecol Evol 30:42–49CrossRefGoogle Scholar