When the first prehistoric people trekked into South America toward the end of the Ice Age, they found a wondrous, lush continent inhabited by all manner of strange creatures like giant ground sloths and car-sized armadillos.
But these hunter-gatherers proceeded to behave like an "invasive species," with their population surging then crashing as they relentlessly depleted natural resources. Only much later did people muster exponential population growth after forming fixed settlements with domesticated crops and animals.
Those are the findings of research published on Wednesday in the journal Nature that provides the most comprehensive look to date of the peopling of South America, the last habitable continent colonized by humankind.