|SREL Reprint #2040|
GENETIC CORRELATES OF FITNESS IN THE GREEN TREEFROG, HYLA CINEREA
SUSAN McALPINE1,3 AND MICHAEL H. SMITH 1,2
ABSTRACT: Effects of an individual's genotype on its fitness may vary with
environmental conditions or across time. Green treefrogs, Hyla cinerea, were
collected from a single pond for three consecutive summers (1989-1991) and
identified as belonging to one of four groups: calling males, mated males, mated
females, and juvenile metamorphs. We used eight polymorphic loci to examine
differences among groups and across years. Heterozygosity at the isocitrate
dehydrogenase-2 (IDH-2) locus was associated with enhanced overwinter
survival of juveniles and male mating success; however, the relationship was not
consistent across time. The association at the IDH-2 locus may be weak or the
result of an interaction and, therefore, seen only under certain conditions. A shift in
allelic and genotypic frequencies corresponded to changes in heterozygosity.
Although the exact cause of the association is not known, this study illustrates the
temporally dynamic nature of the genetics of natural populations. Multilocus
heterozygosity did not appear to be a good indicator of survival or mating success
in H. cinerea.
SREL Reprint #2040
McAlpine, S. and M.H. Smith. 1995. Genetic correlates of fitness in the green treefrog, Hyla cinerea. Herpetologica 51:393-400.