SANTA CRUZ, CA--Mothers know best when it comes to dressing their children, at least among side-blotched lizards, a common species in the western United States. Researchers at the University of California, Santa Cruz, have found that female side-blotched lizards are able to induce different color patterns in their offspring in response to social cues, "dressing" their progeny in patterns they will wear for the rest of their lives. The mother's influence gives her progeny the patterns most likely to ensure success under the conditions they will encounter as adults.
In a paper published June 10 in the online early edition of the journal Ecology Letters (and in a later print issue), the researchers reported that female side-blotched lizards give an extra dose of the hormone estradiol to their eggs in certain social circumstances. The extra hormone affects the back patterns of lizards that hatch from those eggs, creating either lengthwise stripes down their backs or bars stretching from side to side. Whether they get stripes or bars depends on the genes for other traits.
"This is the first example in which exposure to the mother's hormones changes such a fundamental aspect of appearance. Even more exciting is that the mother has different patterns at her disposal, so she can ensure a good match between back patterns and other traits that her offspring possess," said Lesley Lancaster, a UCSC graduate student and first author of the paper.
Coauthor Barry Sinervo, professor of ecology and evolutionary biology, is Lancaster's adviser and has been studying side-blotched lizards for nearly 20 years. He said the lizards' main predator, the coachwhip snake, is a highly efficient hunter, and the lizards need just the right combination of traits to avoid being eaten.
"The females are dressing their progeny for success, because they need a different back pattern in different conditions," Sinervo said. "It's like fashion--she wants to mak
Contact: Tim Stephens
University of California - Santa Cruz