Abstract
Two species of mosquitofish (family Poeciliidae) known to hybridize in nature were introduced into freshwater habitats inside Biosphere 2, and their population genetics were monitored after 2 years. Within four to six generations, nuclear and cytoplasmic markers characteristic of Gambusia holbrooki had risen greatly in frequency, although some Gambusia affinis alleles and haplotypes were retained primarily in recombinant genotypes, indicative of introgressive hybridization. The temporal cytonuclear dynamics proved similar to population genetic changes observed in replicated experimental hybrid populations outside of Biosphere 2, thus indicating strong directional selection favoring G. holbrooki genotypes across the range of environments monitored. When interpreted in the context of species-specific population demographies observed previously, results suggest that the extremely rapid evolution in these zones of secondary contact is attributable primarily to species differences in life-history traits.
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- Brown W. M. Polymorphism in mitochondrial DNA of humans as revealed by restriction endonuclease analysis. Proc Natl Acad Sci U S A. 1980 Jun;77(6):3605–3609. doi: 10.1073/pnas.77.6.3605. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marusyk R., Sergeant A. A simple method for dialysis of small-volume samples. Anal Biochem. 1980 Jul 1;105(2):403–404. doi: 10.1016/0003-2697(80)90477-7. [DOI] [PubMed] [Google Scholar]
- Stearns S. C. Life-history tactics: a review of the ideas. Q Rev Biol. 1976 Mar;51(1):3–47. doi: 10.1086/409052. [DOI] [PubMed] [Google Scholar]
- Tamura K., Aotsuka T. Rapid isolation method of animal mitochondrial DNA by the alkaline lysis procedure. Biochem Genet. 1988 Dec;26(11-12):815–819. doi: 10.1007/BF02395525. [DOI] [PubMed] [Google Scholar]