Fig. 1

Expansions and contractions of gene families in 17 species including chicken, turtle, frog and 14 teleost species. Gene expansions and contractions assessed by regressing gene counts at internal (ancestral) vs. external (extant) nodes, and the expansions and contractions within each gene family with P-value > 0.05 were assessed as statistically significant. Colors in red represent expansions and blue represent contractions