How does the whale become the world's largest animal?

Whales are the largest animals that ever existed on this Earth, bigger than the dinosaurs. These giant animals roam the ocean to find food, but not always. Millions of years ago they were residents on land.

But they are not always the giants of the sea. Rewind the clock about 50 million years, you won't find any whales here. You have to go ashore, meet Pakicetus - the first whale.

Life on Earth has spent millions of years getting the land above sea level as it is now. But whales use all that effort to do the opposite. From 50 to 40 million years ago, they turned their four legs into flippers. In fact, some whales today still have hindquarters!

Blue whale is the largest animal on Earth.

Once sinking into the water, their weight under gravity is no longer important, so they can grow in a very large proportion theoretically. And they really have developed that way. Today, a blue whale is 10 times bigger than Pakicetus.

But this transformation does not grow as slowly and steadily as you think. In fact, for the next 37 million years, not so that whales are increasing in size, otherwise they are still small. And only about 5.5 meters long. This makes them easy prey for predators, like giant sharks.

It wasn't until about 3 million years ago that the ice age tilted the whale scales. The temperature and flow of the ocean has changed the plankton and plankton. It was a buffet buffet for dorsal whales , so they were bigger. And as they get bigger and bigger, they go further to find more food to grow more.

Three million years later, humpback whales , a typical example of whales with the longest migratory whale of any mammal on Earth, have traveled more than 5,000 miles a year. As a result, modern whales are the largest species we have ever had in history.

Like the biggest blue whale . It's heavier than a Boeing 757. There's a navel the size of a disc. And its vascular network, if you put them in a row, can extend from Pluto to the sun and back more than twice and a half!

In fact, the biggest blue whale, so big that scientists think they may have reached the physical limit. When they open wide mouths to eat, their mouths can be equal to a large living room. And, they only take up to 10 seconds to close their mouths.

Scientists estimate that when a whale is about 33.5 meters long, it cannot close its mouth before the prey escapes. So maybe we are seeing the biggest whales that can exist. Fortunately for us, they mainly eat mollusks.