How whales became biggest animals on Earth

Blue whales have a maximum recorded weight of 173 tonnes and can grow up to 29.9 metres in length. However, until a few million years ago, whales rarely grew over 10 metres.

Evolutionary process

Researchers said that evolutionary shift, which took place at the beginning of the Ice Ages, corresponds to climatic changes that would have reshaped whales' food supply in the world's oceans.