5 WHERE DID ALL THE ANIMALS GO

CHAPTER 4 WHERE DID ALL THE ANIMALS GO?

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WHALE GRANDPA IN THE BEGINNING, HUMANS DIDN'T LIVE ALL OVER THE world—only in some parts. Our Sapiens ancestors lived in Africa, Neanderthals lived in Europe and the Middle East, Denisovans lived in Asia, and the small humans of Flores Island lived on Flores Island. In many other parts of the world, there were no humans at all. There were no humans in America or in Australia, or on many islands like Japan, New Zealand, Madagascar and Hawaii. This is because humans were not very good swimmers. They could sometimes reach islands that were really close to the mainland, like Flores, but they couldn't cross the open sea to reach places like Australia or Hawaii. When our Sapiens ancestors left Africa some 70,000 years ago, they started out by walking everywhere. They walked to Europe, where they met the Neanderthals; they walked to Asia, where they met the Denisovans; and they walked on and on until they reached the furthest end of Asia… and couldn't walk any further. But that didn't stop them because they now had a great idea. They knew that wood floats on water, so they tied logs together to make rafts, or they hollowed out tree trunks to make canoes—and they went to sea.

This was an amazing achievement. There are other animals that started out living on land and then evolved to live in the sea. For example, the ancient ancestors of whales were land animals that were no bigger than a large dog. Around 50 million years ago, some of these doglike animals started spending part of their time in rivers and lakes, hunting fish and other small creatures. Scientists discovered the skeleton of one of these animals in Pakistan, and they called it Pakicetus. The descendants of Pakicetus adapted to living in water; they spent more and more of their time in rivers, rarely venturing on to land. Their feet, which they no longer needed for walking, evolved into flippers. Their tails also changed to better help with swimming. Eventually, these animals swam out to sea: completely abandoning land, they spent their whole lives deep in the ocean. And their bodies adapted, growing enormous, until they became whales. But this process took millions and millions of years. Not one of the animals felt the change during his own lifetime. Not one of them started life as a small land animal and grew up to become a giant whale in the ocean. And none of them felt that they were a quarter-whale or a half-whale. At every step along the way, they were what they were, and that was good enough for them. If one of those doglike whale ancestors met a present-day whale, he would never guess that this giant sea monster was his relative. And whales are probably not the last step either. They might continue to evolve, and who knows what they'll look like in 50 million years! Unlike whales, Sapiens didn't have to wait for their bodies to evolve when they wanted to cross the sea; they just invented new tools. They didn't start growing flippers; they started building boats. And it didn't take them millions of years; it took just a few generations. When Sapiens first learned to build boats, they rowed to islands they could see from the shore. Then they rowed on, from one island to another, until they reached the farthest island. They couldn't see any more islands in the distance. Maybe this was the end of the world?

But they didn't stop there. Perhaps some adventurous people said that there might be more islands hiding beyond the horizon. 'How do you know there are more islands?' their cautious friends asked. 'You haven't seen them'. 'How do you know there aren't more islands?' they replied. 'You haven't been there.' Anyway, a group of people must have decided to take the risk and sail into the unknown to see for themselves. They loaded as much food and water as they could on to their rafts and into their canoes and started rowing. And they rowed and rowed, until they could no longer see the island where their brave journey started… but they still couldn't see any new islands in the distance. And now their food and water were running low. If they went any further, they might not have enough provisions to make the journey back. What would you do if you were in one of those boats? Some of the adventurers probably thought it was too dangerous and turned back. But others decided to go on. Maybe one of them saw a bird flying up ahead and thought, 'That bird must be going somewhere, so there must be land ahead!' And on they rowed. And on. And on. Until they finally reached Australia. That was about 50,000 years ago. The journey made by the first people to reach Australia is one of the most important events in history. It's even more important than Columbus's journey to America, or the journey Neil Armstrong and his friends made to the Moon. The moment when the first humans set foot on an Australian beach was the moment when we humans became the most dangerous animal in the world—the rulers of planet Earth. Until then, humans had had a relatively small influence on their