Although direct DNA sequencing may allow rapid and high quality comparative phylogenetic analyses among species, such an approach may not be the most efficient method by which to make a large number of cross-species comparisons. We illustrate the use of Denaturing Gradient Gel Electrophoresis (DGGE) to screen a D2 Dopamine Receptor intron for DNA sequence variation, both within and between closely related species, in order to infer their evolutionary relationships. Our results suggest that: a) humans have less genetic variation than the great apes; b) pygmy chimpanzees have less genetic variation than common chimpanzees; and c) DNA sequence comparative analyses of primates require adequate sampling, both in number and in geographical range.
- denaturing gradient gel electrophoresis
- molecular evolution