DNA and Amphibian Life History

Abstract

Data are presented on the amount of DNA in absorption units per nucleus for 43 species of frogs belonging to nine families. Values range from 4.5 au/nucleus in Scaphiopus holbrookii to 26 in Rana catesbeiana. Comparison of amounts of nuclear DNA and of minimum known durations of the larval stages indicates that the species that have the least amounts of nuclear DNA pass through the larval stages most rapidly. Data are also presented on the amount of nuclear DNA of two species of salamanders. It is suggested that a high level of DNA and low rate of development restrict some frogs and salamanders to the vicinity of permanent water while a low level of DNA and rapid rate of development allow other frogs to invade arid environments.