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 October 31, 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 October 31, 2014).

Share This



More Earth & Climate News

Friday, October 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How A Chorus Led Scientists To A New Frog Species

How A Chorus Led Scientists To A New Frog Species

Newsy (Oct. 30, 2014) A frog noticed by a conservationist on New York's Staten Island has been confirmed as a new species after extensive study and genetic testing. Video provided by Newsy
Powered by NewsLook.com
Raw: Hawaii Lava Approaching Village Road

Raw: Hawaii Lava Approaching Village Road

AP (Oct. 30, 2014) The lava flow on the Big Island of Hawaii was 225 yards from Pahoa Village Road on Wednesday night. The lava is slowing down but still approaching the village. (Oct. 30) Video provided by AP
Powered by NewsLook.com
Endangered Carpathian Ponies Are Making a Comeback in Poland

Endangered Carpathian Ponies Are Making a Comeback in Poland

AFP (Oct. 29, 2014) At the foot of the rugged Carpathian mountains near the Polish-Ukrainian border, ranchers and scientists are trying to protect the Carpathian pony, known as the Hucul in Polish. Duration: 02:17 Video provided by AFP
Powered by NewsLook.com
Deadly Mudslide in Sri Lanka Buries Houses

Deadly Mudslide in Sri Lanka Buries Houses

AP (Oct. 29, 2014) A mudslide triggered by monsoon rains buried scores of workers' houses at a tea plantation in central Sri Lanka on Wednesday, killing at least 10 people and leaving more than 250 missing, an official said. (Oct. 29) Video provided by AP
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