Evolution

Hatcheries breed smaller salmon eggs, possibly harming wild fish

Continental drift, climate shifts helped guide squirrel evolution

Male fruit flies are more discriminating than expected in choosing a mate

Madagascar's meat-eaters arrived all at once, by sea

Fungus-farming ants, their crop, and a pathogen share a long history

Modern birds suggest evolutionary route to flight

Some stick insects got wings back after their ancestors lost them

Discovery of an ancient skull fills a crucial gap in human evolution

Gene-chip studies show more differences than previously thought

Arthropods' many adaptations for life on land have a common source

Long, dark manes are de rigueur for studly lions

Poor nutrition may have held back biodiversity for a billion years

Gene related to spoken language may be less than 200,000 years old

Mutation allows first real test of theory about imprinted genes

New theory suggests that dozens of protocells, not single ancestral type, led to today's life forms

Some bacteria might have evolved disguises to escape predators--not their hosts' defenses