Featured Research

from universities, journals, and other organizations

Scientists 'surprised' to discover very early ancestors survived on tropical plants, new study suggests

Date:
December 14, 2012
Source:
University of Oxford
Summary:
Between three million and 3.5 million years ago, the diet of our very early ancestors in central Africa is likely to have consisted mainly of tropical grasses and sedges, new research suggests.

New research suggests that between three million and 3.5 million years ago, the diet of our very early ancestors in central Africa is likely to have consisted mainly of tropical grasses and sedges.
Credit: timur1970 / Fotolia

Researchers involved in a new study led by Oxford University have found that between three million and 3.5 million years ago, the diet of our very early ancestors in central Africa is likely to have consisted mainly of tropical grasses and sedges. The findings are published in the early online edition of Proceedings of the National Academy of Sciences.

Related Articles


An international research team extracted information from the fossilised teeth of three Australopithecus bahrelghazali individuals -- the first early hominins excavated at two sites in Chad. Professor Julia Lee-Thorp from Oxford University with researchers from Chad, France and the US analysed the carbon isotope ratios in the teeth and found the signature of a diet rich in foods derived from C4 plants.

Professor Lee-Thorp, a specialist in isotopic analyses of fossil tooth enamel, from the Research Laboratory for Archaeology and the History of Art, said: "We found evidence suggesting that early hominins, in central Africa at least, ate a diet mainly composed of tropical grasses and sedges. No African great apes, including chimpanzees, eat this type of food despite the fact it grows in abundance in tropical and subtropical regions. The only notable exception is the savannah baboon which still forages for these types of plants today. We were surprised to discover that early hominins appear to have consumed more than even the baboons."

The research paper suggests this discovery demonstrates how early hominins experienced a shift in their diet relatively early, at least in Central Africa. The finding is significant in signalling how early humans were able to survive in open landscapes with few trees, rather than sticking only to types of terrain containing many trees. This allowed them to move out of the earliest ancestral forests or denser woodlands, and occupy and exploit new environments much farther afield, says the study.

The fossils of the three individuals, ranging between three million and 3.5 million years old, originate from two sites in the Djurab desert. Today this is a dry, hyper-arid environment near the ancient Bahr el Ghazal channel which links the southern and northern Lake Chad sub-basins. However, in their paper the authors observe that at the time when Australopithecus bahrelghazali roamed, the area would have had reeds and sedges growing around a network of shallow lakes, with floodplains and wooded grasslands beyond.

Previously, it was widely believed that early human ancestors acquired tougher tooth enamel, large grinding teeth and powerful muscles so they could eat foods like hard nuts and seeds. This research finding suggests that the diet of early hominins diverged from that of the standard great ape at a much earlier stage. The authors argue that it is unlikely that the hominins would have eaten the leaves of the tropical grasses as they would have been too abrasive and tough to break down and digest. Instead, they suggest that these early hominins may have relied on the roots, corms and bulbs at the base of the plant.

Professor Lee-Thorp said: "Based on our carbon isotope data we can't exclude the possibility that the hominins' diets may have included animals that in turn ate the tropical grasses. But as neither humans nor other primates have diets rich in animal food, and of course the hominins are not equipped as carnivores are with sharp teeth, we can assume that they ate the tropical grasses and the sedges directly."


Story Source:

The above story is based on materials provided by University of Oxford. Note: Materials may be edited for content and length.


Journal Reference:

  1. J. Lee-Thorp, A. Likius, H. T. Mackaye, P. Vignaud, M. Sponheimer, M. Brunet. From the Cover: Isotopic evidence for an early shift to C4 resources by Pliocene hominins in Chad. Proceedings of the National Academy of Sciences, 2012; 109 (50): 20369 DOI: 10.1073/pnas.1204209109

Cite This Page:

University of Oxford. "Scientists 'surprised' to discover very early ancestors survived on tropical plants, new study suggests." ScienceDaily. ScienceDaily, 14 December 2012. <www.sciencedaily.com/releases/2012/12/121214200916.htm>.
University of Oxford. (2012, December 14). Scientists 'surprised' to discover very early ancestors survived on tropical plants, new study suggests. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/2012/12/121214200916.htm
University of Oxford. "Scientists 'surprised' to discover very early ancestors survived on tropical plants, new study suggests." ScienceDaily. www.sciencedaily.com/releases/2012/12/121214200916.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Arctic Warming Twice As Fast As Rest Of Planet

Arctic Warming Twice As Fast As Rest Of Planet

Newsy (Dec. 18, 2014) The Arctic is warming twice as fast as the rest of the planet, thanks in part to something called feedback. Video provided by Newsy
Powered by NewsLook.com
Prenatal Exposure To Pollution Might Increase Autism Risk

Prenatal Exposure To Pollution Might Increase Autism Risk

Newsy (Dec. 18, 2014) Harvard researchers found children whose mothers were exposed to high pollution levels in the third trimester were twice as likely to develop autism. Video provided by Newsy
Powered by NewsLook.com
Ivory Trade Boom Swamps Law Efforts

Ivory Trade Boom Swamps Law Efforts

Reuters - Business Video Online (Dec. 17, 2014) Demand for ivory has claimed the lives of tens of thousands of African elephants and now a conservation report says the illegal trade is overwhelming efforts to enforce the law. Amy Pollock reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins