A molecular phylogenetic study of ecological diversification in the Australian lizard genus Ctenophorus

We present phylogenetic analyses of the lizard genus Ctenophorus using 1,63 9 aligned positions of mitochondrial DNA sequences containing 799 parsimony -informative characters for samples of 22 species of Ctenophorus and 12 add itional Australian agamid genera. Sequences from three protein-coding genes (ND1, ND2, and COT) and eight intervening tRNA genes are examined using bo th parsimony and maximum-likelihood analyses. Species of Ctenophorus form a monophyletic group with Rankinia adelaidensis, which we suggest placing in Ctenophorus. Ecological differentiation among species of Ctenophorus is mo st evident in the kinds of habitats used for shelter. Phylogenetic analyses suggest that the ancestral condition is to use burrows for shelter, and th at habits of sheltering in rocks and shrubs/hummock grasses represent separ ately derived conditions. Ctenophorus appears to have undergone extensive c ladogenesis approximately 10-12 million years ago, with all three major eco logical modes being established at that time. (C) 2001 Wiley-Liss, Inc.