During the past 40 million years, three great lineages arose in the dog family.
Adaptations to deepwater living make the fishes of the deep sea particularly vulnerable to overfishing.
The vaquita, the world's smallest porpoise, lives only in the northern Gulf of California. With just 200 individuals remaining, can the species survive?
Ancient genes, recycled and repurposed, control embryonic development in organisms of striking diversity.