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Male lizard cooperation adds new wrinkle to evolutionary theory

Blue-throated lizards that help each other achieve reproductive success are also helping scientists understand how social cooperation evolved. Most examples of cooperative behavior in animals involve cooperation between genetically related individuals, which is explained by the theory of “kin selection.” Now, researchers have described an example of cooperation between genetically similar but unrelated members of a lizard species common in the western United States. Their findings, published in the June 20 issue of the journal Science, shed new light on the evolution of cooperation and social behavior.

Lowly coot can count

Coots, the Rodney Dangerfields of the bird world, just might start to get some respect as a result of a new study showing that these common marsh birds are able to recognize and count their own eggs, even in the presence of eggs laid by other birds.
The counting ability of female coots is part of a sophisticated set of defense mechanisms used to thwart other coots who lay eggs in their neighbors’ nests, according to Bruce Lyon, an assistant professor of ecology and evolutionary biology at the University of California, Santa Cruz. Lyon studied hundreds of coot nests in British Columbia during a four-year investigation. His latest findings appear in the April 3 issue of the scientific journal Nature.