281K views · 3.9K reactions | Earth’s history includes five major mass extinctions, with up to 95% of species lost in events driven by impacts, volcanic eruptions, or potentially solar outbursts. The terminal Pleistocene extinction, though not part of the “Great Five,” saw the disappearance of North America’s megafauna, focusing on top predators and large mammals. | The Randall Carlson | Facebook

By the nineteenth century most plausible explanations for the Late Pleistocene extinctions had already been proposed. Today only two remain seriously considered: human activity or climate change. Epidemic disease is improbable, unable to cross such vast taxonomic and geographic boundaries. Classic cosmic impacts fail as well, since the extinctions were not globally synchronous. The pattern of losses still challenges simple explanations and invites a deeper look at the forces shaping Earth’s past

106K views · 476 reactions | Top Priority: Addressing Climate Change Now! Bill Nye The Science Guy, on a topic that's making the most headlines lately | Big Think | Facebook