Add Yahoo as a preferred source to see more of our stories on Google. Marine mammals can hold their breath for extended periods underwater; the question is, how do they know when it's time to ...

Webbed feet, flipper-like wings and unique feathers all helped penguins adapt to life underwater. But by resurrecting two ancient versions of hemoglobin, a research team has shown that the evolution ...

Seals, dolphins and otters share the same physiological constraints as humans do when we return to our evolutionary home – the sea. The most instantly identifiable of these is the inability to breathe ...