Feature

Smart from the start

Animal embryos get some respect for their survival skills

By Susan Milius

- More than 2 years ago

Karen Warkentin speaks admiringly of the eggs of red-eyed tree frogs because, for one thing, they know what’s shaking.

SMART FROM THE START Three-day-old embryos of red-eyed tree frogs position their big, branching gills near the oxygen-rich egg surface. K. Warkentin/Boston Univ. and Smithsonian Tropical Research Institute

PRENATAL ESCAPE A female pale spitting spider can’t spit at predators while carrying an egg mass.