Cowbirds have long been known to lay eggs in the nests of other birds, which then raise the cowbirds' young as their own. Sneaky, perhaps, but not Scarface. Now, however, a University of Florida study finds that cowbirds actually ransack and destroy the nests of warblers that don't buy into the ruse and raise their young.
Flexibly drawing inferences about the intentions of other individuals in order to cooperate in complex tasks is a basic part of everyday life that we humans take for granted. But, according to evolutionary psychologist Brian Hare at the Max Planck Institute in Germany, this ability is present in other species as well.
Scientists at North Carolina State University have discovered that the fungus-like pathogen that caused the 1840s Irish potato famine originally came from the Andes of South America. By comparing the sequences of both the nuclear and the cellular powerhouse, mitochondria, of nearly 100 pathogen samples from South America, Central America, North America and Europe, Dr. Jean Beagle Ristaino, professor of plant pathology at NC State, and a small team of researchers created "gene genealogies" that point the finger at an Andean point of origin for the pathogen, which is known as Phytophthora infestans.
Why do some individuals sacrifice their own self-interest to help others? The evolution and maintenance of cooperative behavior is a classic puzzle in evolutionary biology. In some animal societies, cooperation occurs in close-knit family groups and kin selection explains apparently selfless behavior. Not so for the lance-tailed manakin. Males of this little tropical bird cooperate in spectacular courtship displays with unrelated partners, and the benefits of lending a helping wing may only come years down the line.