Sunday, July 13, 2014

First explorers of Eurasia were apes, not us


Long after apes went extinct in Eurasia, our distant Pacifica ancestors began their migration out of Africa.  The first humans diverged from apes in Africa about 8 to 6 million years ago, (PBS, New Scientist).  Just a reminder, we are still evolving.

Science Daily/Featured Research, 5/21/14. "Ape ancestor's teeth provide glimpse into their diets and environments:  helped apes move to Eurasia, and may have led to extinction."

"Newly analyzed tooth samples from the great apes of the Miocene indicate that the same dietary specialization that allowed the apes to move from Africa to Eurasia may have led to their extinction, according to results published May 21, 2014, in the open access journal PLOS ONE by Daniel DeMiguel from the Institut Catalá de Palontologia Miquel Crusafont (Spain) and colleagues.

Not much credit, but we were
the first explorers of Eurasia
Apes expanded into Eurasia from Africa during the Miocene (14 to 7 million years ago) and evolved to survive in new habitat. Their diet closely relates to the environment in which they live and each type of diet wears the teeth differently. To better understand the apes' diet during their evolution and expansion into new habitat, scientists analyzed newly-discovered wearing in the teeth of 15 upper and lower molars belonging to apes from five extinct taxa found in Spain from the mid- to late-Miocene (which overall comprise a time span between 12.3–12.2 and 9.7 Ma). They combined these analyses with previously collected data for other Western Eurasian apes, categorizing the wear on the teeth into one of three ape diets: hard-object feeders (e.g., hard fruits, seeds), mixed food feeders (e.g. fruit), and leaf feeders.

Map of Eurasia
Migration out of Africa to Eurasia
Previous data collected elsewhere in Europe and Turkey suggested that the great ape's diet evolved from hard-shelled fruits and seeds to leaves, but these findings only contained samples from the early-Middle and Late Miocene, while lack data from the epoch of highest diversity of hominoids in Western Europe.  In their research, the scientists found that in contrast with the diet of hard-shelled fruits and seeds at the beginning of the movement of great apes to Eurasia, soft and mixed fruit-eating coexisted with hard-object feeding in the Late Miocene, and a diet specializing in leaves did not evolve. The authors suggest that a progressive dietary diversification may have occurred due to competition and changes in the environment, but that this specialization may have ultimately lead to their extinction when more drastic environmental changes took place."

Story Source:  The above story is based on materials provided by Public Library of Science (PLOS). Note: Materials may be edited for content and length. Journal Reference: Daniel DeMiguel, David M. Alba, Salvador Moyà-Solà. Dietary Specialization during the Evolution of Western Eurasian Hominoids and the Extinction of European Great Apes. PLoS ONE, 2014; 9 (5): e97442 DOI: 10.1371/journal.pone.0097442.

Reference Eurasia - About.com/Geography. .... "Nearly all of Eurasia sits upon the Eurasian Plate, one of several large plates that cover our planet. This map shows the world's plates and it is clear that there is no geologic boundary between Europe and Asia - they are combined as Eurasia. Part of eastern Russia lies on the North American Plate, India lies on the Indian Place and the Arabian Peninsula lies on the Arabian Plate."  World history for us all.  "Eurasia is the landmass made up of Asia and Europe. Today, this term is widely used in history and geography education. The idea that Europe and Asia are separate continents goes back many centuries, but scholars who accept the definition of a continent as "a large landmass surrounded, or nearly surrounded, by water" know that the definition applies to neither Europe nor Asia because these two landmasses are conjoined. Moreover, the Ural Mountains, which eighteenth-century European geographers designated as the proper boundary between the European and Asian continents, have never been a serious obstacle to the flow of migrants, armies, trade goods, or ideas. On this site, we define Europe as a subcontinent of Eurasia (or of Afroeurasia), parallel to South Asia or to the Indochinese peninsula.

National Geographic.  "Our species is an African one: Africa is where we first evolved, and where we have spent the majority of our time on Earth. The earliest fossils of recognizably modern Homo sapiens appear in the fossil record at Omo Kibish in Ethiopia, around 200,000 years ago. Although earlier fossils may be found over the coming years, this is our best understanding of when and approximately where we originated. According to the genetic and paleontological record, we only started to leave Africa between 60,000 and 70,000 years ago. What set this in motion is uncertain, but we think it has something to do with major climatic shifts that were happening around that time—a sudden cooling in the Earth’s climate driven by the onset of one of the worst parts of the last Ice Age. This cold snap would have made life difficult for our African ancestors, and the genetic evidence points to a sharp reduction in population size around this time. In fact, the human population likely dropped to fewer than 10,000. We were holding on by a thread." 

Note photograph/graphic  Cool ape from  Freaking News; map from World history for us all. 

Posted by Kathy Meeh

2 comments:

Anonymous said...

Interesting.

How did monkeys get to S. America then? Evidence is they've been there 40 mil years. Land bridge? Then why no fossils in N America? Some say rafts of vegetation across the Atlantic. But they really don't know for sure.

Same with humans. Some Central American DNA shows they are closer to Polynesian roots than Russian/Inuit .

Anonymous said...

"South America and Africa separated around 160 million years ago. The first mammals did not show up until 66 million years ago. The Oglicene period (about 45 million years ago) is when monkeys first appeared in South America."

Did monkeys develop in S America independent of old world primates?