THE ORIGIN AND EVOLUTION OF PARTHENOGENESIS IN HETERONOTIA-BINOEI (GEKKONIDAE) - RECIPROCAL ORIGINS AND DIVERSE MITOCHONDRIAL-DNA IN WESTERN POPULATIONS

Parthenogenetic lines of the Heteronotia binoei complex are geneticall y diverse, of hybrid origin, and geographically widespread, ranging fr om central Australia to the west coast. Analysis of the western popula tions revealed a class of mitochondrial DNA (mtDNA) approximately 12% different from the mtDNAs found among parthenogens further east. Detai led analysis of mtDNAs from 59 western individuals revealed far greate r diversity than previously reported for any parthenogenetic vertebrat e. Phylogenetic comparisons with mtDNAs from the bisexual parental spe cies identified the maternal parent(s) as coming from the SM6 species, most probably from west coast populations. This ancestry contrasts wi th that of the more eastern parthenogenetic lines, which had as parent s females of the other bisexual parental species, CA6. The nucleotide diversity of mtDNA among the western parthenogens, although higher tha n usual (xBAR = 0.38%), is low compared with the variation found withi n (2.1%) and among (3.9-7.8%) SM6 populations. This diversity illustra tes the importance of rigorous sampling of related bisexual population s for interpreting variation among unisexuals. Despite the high mtDNA diversity, these parthenogens probably arose from a relatively small g eographic area. The distinct geographic ranges of parthenogens that ha ve the two major classes of mtDNA suggest that the western populations arose separately and further to the west than did the other lines. If so, then the two groups of parthenogenetic lines should be regarded a s separate species.