Send to

Choose Destination
See comment in PubMed Commons below
Genetics. 1995 Apr;139(4):1805-13.

The population genetics of speciation: the evolution of hybrid incompatibilities.

Author information

  • 1Department of Biology, University of Rochester, New York 14627, USA.


Speciation often results from the accumulation of "complementary genes," i.e., from genes that, while having no deleterious effect within species, cause inviability or sterility when brought together with genes from another species. Here I model speciation as the accumulation of genic incompatibilities between diverging populations. Several results are obtained. First, and most important, the number of genic incompatibilities between taxa increases much faster than linearly with time. In particular, the probability of speciation increases at least as fast as the square of the time since separation between two taxa. Second, as Muller realized, all hybrid incompatibilities must initially be asymmetric. Third, at loci that have diverged between taxa, evolutionarily derived alleles cause hybrid problems far more often than ancestral alleles. Last, it is "easier" to evolve complex hybrid incompatibilities requiring the simultaneous action of three or more loci than to evolve simple incompatibilities between pairs of genes. These results have several important implications for genetic analyses of speciation.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center