Human evolution: Mysterious extinct primate fossils from China reveal why humans never evolved in Asia; Ancient climate change to blame

Scientists have unearthed a treasure trove of six mysterious primate fossils that are proving to be pivotal in providing answers to evolution of primates and humans. These previously unknown extinct primate species inhabited the trees of Southern China 34 million years ago.

According to the study, as primates are too sensitive to climate change, they could not withstand the drastic cooling that made Asia inhabitable during that time. Soon they died.

“At the Eocene-Oligocene boundary, because of the rearrangement of Earth's major tectonic plates, you had a rapid drop in temperature and humidity. Primates like it warm and wet, so they faced hard times around the world -- to the extent that they went extinct in North America and Europe. Of course, primates somehow survived in Africa and Southern Asia, because we're still around to talk about it,” co-author of the study K. Christopher Beard, senior curator at the University of Kansas' Biodiversity Institute, said in a press release.

As anthropoid primates, from whom monkeys, apes and humans came, first appeared in Asia, it is important to understand their fate on the continent to find out more about human evolution. At some point in the Eocene, Asian anthropoids migrated to Africa and started diversifying. This is where “the geographic focal point of anthropoid evolution” shifted from Asia to Africa.

It has always baffled scientists as to why humans evolved only from Africa and not elsewhere. Now, they have an answer. It was the ancient climate change that killed off all primates from the world, except Africa.

Thus, it is highly interesting to see that climate change even affected early primates from where Homo sapiens evolved. However, it was just the opposite of modern day’s global warming. During the Eocene-Oligocene period, earth was already warm. But it started cooling down to such extent that it rendered most parts inhospitable.

The fossil discovery was headed by Paleoanthropology Institute in Beijing and the Chinese Academy of Science's Vertebrate Paleontology. Four of the six fossils discovered are very similar to Madagascar's lemurs, one more of a monkey-like primate and the last one similar to nocturnal insect and lizard-eating tarsiers of the Philippines and Indonesia.