Evolution: Monkey see, monkey do (Introduction)

by David Turell , Saturday, May 07, 2016, 14:40 (3124 days ago)

Fossil finds in China seem to redefine the course of evolution. It appears monkeys were in Asia 40 million years ago and traveled to Africa to complete their evolution to us. Weather change from hot and humid to much colder is also involved:-https://www.washingtonpost.com/news/speaking-of-science/wp/2016/05/06/these-ancient-asian-primate-fossils-might-be-the-missing-pieces-of-a-major-evolutionary-puzzle/?wpmm=1&wpisrc=nl_headlines-"But then, in the 1990s, researchers in China made a surprising discovery: The fossil of a tiny monkey-like creature that was some 10 million years older than anything that had been found in Africa. The ancestors of apes, and ultimately us, seemed to have come from Asia. But they hadn't stayed there.-***-"In a study published Thursday in the journal Science, Beard and his colleagues at the Chinese Academy of Sciences in Beijing report on an “incredible cache” of fossils from 10 previously unknown species uncovered in China's Yunnan province. These fossils help illuminate a new story of our evolution: one in which our primate ancestors evolved in Asia, sailed across a narrow sea to Africa, then were pushed to extinction on their home continent because of drastic climate change. Some of the only primates that survived were the ones whose fossils were just uncovered — primitive creatures that were closer to lemurs than apes and humans living today.-***-"This more convoluted version of our history begins in the Eocene, some 40 million years ago. At this time, Earth's climate was hot and humid, and the continents were just beginning to move into the positions they hold today. India was zooming headlong toward the bottom of Asia (the inevitable collision would one day give rise to the Himalayas). An inland sea flooded the center of the Eurasian land mass. And Africa was an island continent, separated from Asia and Europe by a narrow stretch of ocean.-"Early anthropoid (humanlike) monkeys were flourishing in Asia at that time. But they also, somehow, found a way to migrate across the watery barrier to Africa. And since monkeys don't really swim, scientists' best theory about their migration is — I kid you not — that they sailed across on rafts made of trees.-" A half an acre of land with a bunch of trees growing out of it falls into a river and floats out to sea.”-“'And if there are a bunch of monkeys hanging out in the trees when that happens,” he continued, “suddenly those monkeys become sailors.”-"It was a good thing, too, because climate records show that dramatic changes started ravaging the Earth soon after. Around 34 million years ago, the warm, wet climate of the Eocene gave way to the cooler, drier Oligocene epoch. Tropical forests receded, ... Life for monkeys in Asia suddenly became very, very hard.-***-"Even as Asian anthropoids were dying out in droves, the population of their seafaring African relatives exploded. The species spread and diversified, developing swiftly into the vast variety of primates we know today, from little masked vervets to huge, powerful gorillas to australopithecines such as the famous “Lucy” and, eventually, to us.-***-"Exactly why these primates were so successful is a question for further study, Beard said. It may have been pure chance — evolution rolled the dice in two places, and only one game worked out well. Or it could be that Africa, which was closer to the Equator and less climatically chaotic than Asia, was just a better place to try to survive.-***-"The fossils “fill a gap,” in our understanding of our evolutionary history, Stony Brook University primatologist John Fleagle, who was not involved in the study, told the Christian Science Monitor. They illustrate “a whole aspect of primate evolution that wasn't clearly documented before.”-"They also help pinpoint exactly when “the plot shifted” from Asia to Africa. “Everything that happens subsequently leads to Africa becoming center stage,” Beard said." -Comment: So it isn't just Africa.