Resumen de Land animals can't resist the call of the sea
The first animals that evolved to live exclusively on land did it about 370 million years ago--but on dozens of occasions since, land animals have gone back to exploiting the seas. That might be because the shallow seas around continents are so full of food that they proved irresistible. Some of the most spectacular species now living in the sea have land-living ancestors. Whales are descended from animals similar to deer, while walruses evolved from animals a bit like stoats. What's more, many land-dwelling species go to sea for food: seabirds are an example. Humans also exploit the sea on a massive scale.
