2010/05/03 by Nick Barton · 63 citations
Biochemistry, Genetics and Molecular Biology · Social Sciences · #Evolution and Genetic Dynamics #Genetic diversity and population structure #Evolutionary Game Theory and Cooperation #Natural selection #Genetic algorithm #Selection (genetic algorithm) #Natural (archaeology) #Evolutionary biology #Computer science #Biology #Artificial intelligence #Paleontology
paper · doi:10.1098/rstb.2010.0001
published in Philosophical Transactions of the Royal Society B Biological Sciences 365(1547), 1825-1840 (Royal Society)
openalex publication_date 2010/05/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/15
If distinct biological species are to coexist in sympatry, they must be reproductively isolated and must exploit different limiting resources. A two-niche Levene model is analysed, in which habitat preference and survival depend on underlying additive traits. The population genetics of preference and viability are equivalent. However, there is a linear trade-off between the chances of settling in either niche, whereas viabilities may be constrained arbitrarily. With a convex trade-off, a sexual population evolves a single generalist genotype, whereas with a concave trade-off, disruptive selection favours maximal variance. A pure habitat preference evolves to global linkage equilibrium if mating occurs in a single pool, but remarkably, evolves to pairwise linkage equilibrium within niches if mating is within those niches--independent of the genetics. With a concave trade-off, the population shifts sharply between a unimodal distribution with high gene flow and a bimodal distribution with strong isolation, as the underlying genetic variance increases. However, these alternative states are only simultaneously stable for a narrow parameter range. A sharp threshold is only seen if survival in the 'wrong' niche is low; otherwise, strong isolation is impossible. Gene flow from divergent demes makes speciation much easier in parapatry than in sympatry.