Mitochondrial-DNA Variation in the Polytypic Alaskan Song Sparrow

Abstract

Previous studies of mitochondrial-DNA (mtDNA) variation in the polytypic Song Sparrow (Melospiza melodia) have not found geographic structure of haplotype distri- butions. We used restriction-fragment analysis of mtDNA to analyze geographic variation of Song Sparrows in Alaska, where phenotypic differentiation between populations is greatest. We examined 42 individuals, representing five subspecies, from island and mainland local- ities. In addition, we examined two specimens each from Washington and California. An average of 55 sites per individual distinguished 12 mtDNA haplotypes, which were all closely related (d = 0.001-0.008). Geographic structure was evident in the distribution of haplotype frequencies, but not in their phylogenetic affinities. Received 21 January 1991, accepted 1 August 1991.