The same environmental changes that encouraged humans and other smaller predators to spread to the Americas may also have lowered the population of the megafaun

The same environmental changes that encouraged humans and other smaller predators to spread to the Americas may also have lowered the population of the megafauna. But yes, I tend to believe that the environmental change that killed of the megafauna was the arrival of predators smart enough to use pointy sticks and fire, which we call evolution.