THE RATE OF MITOCHONDRIAL 12S RIBOSOMAL-RNA GENE EVOLUTION IS SIMILARIN FRESH-WATER TURTLES AND MARSUPIALS

Assertions that the ''conventional'' rate of mitochondrial DNA (mtDNA) evolution is reduced in poikilotherms in general and turtles in parti cular were tested for side-necked turtles (Pleurodira: Chelidae), Homo logous data sets of mitochondrial 12S rRNA gene sequences were used to compare the average divergence between the Australian and South Ameri can species for two Gondwanan groups: the chelid turtles and the marsu pials. The mean nucleotide divergences between continental groups for both the turtles and the marsupials are remarkably similar, These data suggest that the rate of evolution of mitochondrial 12S rRNA gene is not-substantially slower in turtles than in the homeothermic marsupial s.