In recent months, the Food and Drug Administration and National Institutes of Health have announced new initiatives to reduce and replace animal testing in biomedical research. Central to these ...

Animals, from worms and sponges to jellyfish and whales, contain anywhere from a few thousand to tens of trillions of nearly genetically identical cells. Depending on the organism, these cells arrange ...

Descriptions of the embryo go back at least to the time of Aristotle, but it has only been since the late 19 th century and early 20 th century that advances in experimental approaches allowed ...