Molecular Evolution Activities
 

This is a comprehensive bibliography (under construction) of primary and secondary sources on the neutral theory of molecular evolution. It currently covers the period 1973-2001.

Author :

Bradley, R. D.;Adkins, R. M.;Honeycutt, R. L.;McDonald, J. H.

Year :

1998

Title :

Nucleotide polymorphism at the alcohol dehydrogenase locus of pocket gophers, genus Geomys

Journal :

Molecular Biology and Evolution

Volume :

15

Issue :

6

Pages :

709-717

Date :

Jun

Short Title :

Nucleotide polymorphism at the alcohol dehydrogenase locus of pocket gophers, genus Geomys

Alternate Journal :

Mol. Biol. Evol.

Custom 2 :

ISI:000073759400010

Abstract :

Using the strictly neutral model as a null hypothesis, we tested for deviations from expected levels of nucleotide polymorphism at the alcohol dehydrogenase locus (Adh-1) within and among four species of pocket gophers (Geomys bursarius major, G. knoxjonesi, G. texensis ilanensis, and G. attwateri). The complete protein-encoding region was examined, and 10 unique alleles, representing both electromorphic and cryptic alleles, were used to test hypotheses (e.g., the neutral model) concerning the maintenance of genetic variation. Nineteen variable sites were identified among the 10 alleles examined, including 9 segregating sites occurring in synonymous positions and 10 that were nonsynonymous. Several statistical methods, including those that test for within-species variation as well as those that examine variation within and among species, failed to reject the null hypothesis that variation (both within and between species of Geomys) at the Adh locus is consistent with the neutral theory. However, there was significant heterogeneity in the ratio of polymorphism to divergence across the gene, with polymorphisms clustered in the first half of the coding region and fixed differences clustered in the second half of the gene. Two alternative hypotheses are discussed as possible explanations for this heterogeneity: an old balanced polymorphism in the first half of the gene or a recent selective sweep in the second half of the gene.

Notes :

Times Cited: 0 ZP497 MOL BIOL EVOL
 -- contributed by John Beatty, March 29, 2002