It starts with animals living during the Ice Age. It also shows how humans became top predators and started hunting mammoths on the continent with deadly spears. We also had to compete with other predators like the Short-faced Bear and the Saber-toothed cats. We destroyed them by depleting their food supply, and making them starve to death. Later after realizing what they done to the great beast's demise they hunted not all the time and then there were no more extinctions in the Americas. That wasn't until pioneers from Europe like 克里斯托弗·哥伦布, several 征服者 and lots of horses were brought by the Conquistadors arrived in North America. Howevever horses are returning to the land of which they evolved in. Also inventing the gun, which in North America, was used primarily for hunting big game animals like the bison. By 1893 only 500 wild buffalo remained, marking the end of the megafauna in the Americas.