May 1, 2021 03:03 AM
https://theconversation.com/one-incredib...ble-157479
INTRO: Humans evolved in Africa, along with chimpanzees, gorillas and monkeys. But primates themselves appear to have evolved elsewhere – likely in Asia – before colonising Africa. At the time, around 50 million years ago, Africa was an island isolated from the rest of the world by ocean – so how did primates get there?
A land bridge is the obvious explanation, but the geological evidence currently argues against it. Instead, we’re left with a far more unlikely scenario: early primates may have rafted to Africa, floating hundreds of miles across oceans on vegetation and debris.
Such oceanic dispersal was once seen as far-fetched and wildly speculative by many scientists. Some still support the land bridge theory, either disputing the geological evidence, or arguing that primate ancestors crossed into Africa long before the current fossil record suggests, before the continents broke up.
But there’s an emerging consensus that oceanic dispersal is far more common than once supposed. Plants, insects, reptiles, rodents and primates have all been found to colonise island continents in this way – including a remarkable Atlantic crossing that took monkeys from Africa to South America 35 million years ago. These events are incredibly rare but, given huge spans of time, such freak events inevitably influence evolution – including our own origins... (MORE - details)
INTRO: Humans evolved in Africa, along with chimpanzees, gorillas and monkeys. But primates themselves appear to have evolved elsewhere – likely in Asia – before colonising Africa. At the time, around 50 million years ago, Africa was an island isolated from the rest of the world by ocean – so how did primates get there?
A land bridge is the obvious explanation, but the geological evidence currently argues against it. Instead, we’re left with a far more unlikely scenario: early primates may have rafted to Africa, floating hundreds of miles across oceans on vegetation and debris.
Such oceanic dispersal was once seen as far-fetched and wildly speculative by many scientists. Some still support the land bridge theory, either disputing the geological evidence, or arguing that primate ancestors crossed into Africa long before the current fossil record suggests, before the continents broke up.
But there’s an emerging consensus that oceanic dispersal is far more common than once supposed. Plants, insects, reptiles, rodents and primates have all been found to colonise island continents in this way – including a remarkable Atlantic crossing that took monkeys from Africa to South America 35 million years ago. These events are incredibly rare but, given huge spans of time, such freak events inevitably influence evolution – including our own origins... (MORE - details)