Navigation Links
Early humans had 'jaws of steel'
Date:2/3/2009

TEMPE, Ariz. Your mother always told you not to use your teeth as tools to open something hard, and she was right. Human skulls have small faces and teeth and are not well-equipped to bite down forcefully on hard objects. Not so of our earliest ancestors, say scientists. New research published in the February 2009 issue of Proceedings of the National Academy of Sciences reveals nut-cracking abilities in our 250-million-year-old relatives that enabled them to alter their diet to adapt to changes in food sources in their environment.

Mark Spencer, an Arizona State University assistant professor, and doctoral student Caitlin Schrein in ASU's School of Human Evolution and Social Change, are part of the international team of researchers who devised the study featured in the article "The feeding biomechanics and dietary ecology of Australopithecus africanus." Using state-of-the-art computer modeling and simulation technology the same kind engineers use to simulate how a car reacts to forces in a front-end collision evolutionary scientists built a virtual model of the A. africanus skull and were able to see just how the jaw operated and what forces it could produce.

"We started with a CT scan of a skull that is one of the most complete specimens of A. africanus that we have," said Spencer, researcher in ASU's Institute of Human Origins and a lead investigator on the project, which was funded by the National Science Foundation and European Union. This would be a later ancestor of Lucy STS5 - who is affectionately known as "Mrs. Ples." The skull, discovered in 1947, has struts on the side of the nose, but no teeth. "We meshed those data with another specimen with teeth to make the virtual model of the bone and tooth structure.

"Then we looked at chimpanzees, who share common features with Australopithecus, and took measurements of how their muscles work and added that to the model. We were able to validate this model by comparing it to a similar model built for a species of monkey called macaques," Spencer explained.

The result a rainbow colored virtual skull that illustrates forces absorbed by the cranial structure in simulated bite scenarios and how their unusual facial features were ideally suited to support the heavy loads of cracking hard nuts.

"It was like watching 'Mrs. Ples' come to life," Spencer said.

"This reinforces the body of research indicating that facial specializations in species of early humans are adaptations due to a specialized diet," said Spencer. "The enlargement of the premolars, the heavy tooth enamel and the evidence now that they were loading forcefully on the molars suggest the size of the objects were larger than the previously hypothesized small seeds and nuts.

"These fall-back foods hard nuts and seeds were important survival strategies during a period of changing climates and food scarcity," he added. "Our research shows that early, pre-stone tool human ancestors solved problems with their jaws that modern humans would have solved with tools."

Human Evolution and Social Change, are part of the international team of researchers who devised the study featured in the article "The feeding biomechanics and dietary ecology of Australopithecus africanus." Using state-of-the-art computer modeling and simulation technology the same kind engineers use to simulate how a car reacts to forces in a front-end collision evolutionary scientists built a virtual model of the A. africanus skull and were able to see just how the jaw operated and what forces it could produce.

"We started with a CT scan of a skull that is one of the most complete specimens of A. africanus that we have," said Spencer, researcher in ASU's Institute of Human Origins and a lead investigator on the project, which was funded by the National Science Foundation and European Union. This would be a later ancestor of Lucy STS5 - who is affectionately known as "Mrs. Ples." The skull, discovered in 1947, has struts on the side of the nose, but no teeth. "We meshed those data with another specimen with teeth to make the virtual model of the bone and tooth structure.

"Then we looked at chimpanzees, who share common features with Australopithecus, and took measurements of how their muscles work and added that to the model. We were able to validate this model by comparing it to a similar model built for a species of monkey called macaques," Spencer explained.

The result a rainbow colored virtual skull that illustrates forces absorbed by the cranial structure in simulated bite scenarios and how their unusual facial features were ideally suited to support the heavy loads of cracking hard nuts.

"It was like watching 'Mrs. Ples' come to life," Spencer said.

"This reinforces the body of research indicating that facial specializations in species of early humans are adaptations due to a specialized diet," said Spencer. "The enlargement of the premolars, the heavy tooth enamel and the evidence now that they were loading forcefully on the molars suggest the size of the objects were larger than the previously hypothesized small seeds and nuts.

"These fall-back foods hard nuts and seeds were important survival strategies during a period of changing climates and food scarcity," he added. "Our research shows that early, pre-stone tool human ancestors solved problems with their jaws that modern humans would have solved with tools."


'/>"/>

Contact: Jodi Guyot
jodi.guyot@asu.edu
480-727-8739
Arizona State University
Source:Eurekalert  

Related biology news :

1. 60 second test could help early diagnosis of common brain diseases
2. Restless legs syndrome affects nearly 2 percent of US/UK children
3. Bleeding, not inflammation, is major cause of early lung infection death
4. Pig study sheds new light on the colonisation of Europe by early farmers
5. Color contrast is seen by the brain early doors
6. Extra gene copies were enough to make early humans mouths water
7. Was ability to run early mans Achilles heel?
8. New technique can be breakthrough for early cancer diagnosis
9. Yam bean a nearly forgotten crop
10. NIH awards nearly $23M to University of Chicago for translational research
11. Yam bean a nearly forgotten crop
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Early humans had 'jaws of steel'
(Date:11/29/2016)... , Nov. 29, 2016 BioDirection, a ... point-of-care products for the objective detection of concussion and ... company has successfully completed a meeting with the U.S. ... Tbit™ blood test Pre-Submission Package. During the meeting company ... system as a precursor to commencement of a planned ...
(Date:11/24/2016)... Nov. 23, 2016 Cercacor today introduced Ember ... their trainers non-invasively measure hemoglobin, Oxygen Content, ... and Respiration Rate in approximately 30 seconds. Smaller than ... and immediate access to key data about their bodies ... training regimen. Hemoglobin carries oxygen to ...
(Date:11/19/2016)... , Nov. 18, 2016 Securus Technologies, a ... for public safety, investigation, corrections and monitoring, announced today ... competitor, ICSolutions, to have an independent technology judge determine ... most modern high tech/sophisticated telephone calling platform, and the ... that they do most of what we do – ...
Breaking Biology News(10 mins):
(Date:11/30/2016)... ... November 30, 2016 , ... SSCI, the established leader in small-molecule cocrystal technology ... latest FDA guidance on pharmaceutical cocrystals as drug substance . The Lunch ... , The event follows the successful November 15th event that took place in Burlingame, ...
(Date:11/30/2016)... (PRWEB) , ... November 30, 2016 , ... ... in the development of a new orally administered treatment for Alzheimer’s disease (AD), ... results of a Phase 2a clinical trial of T3D-959 in mild to moderate ...
(Date:11/30/2016)... London, UK (PRWEB) , ... November 30, 2016 , ... ... old offices on Haymarket after five years and look forward to continuing their expansion ... heart of Soho, an area which has been traditionally favoured by the creative industries, ...
(Date:11/30/2016)... ... November 30, 2016 , ... Microbial ... venture founded by Arianna Huffington, as part of the Thrive Global pop-up store. ... Kit, enabling purchasers to explore the microorganisms in their gut, collectively known as ...
Breaking Biology Technology: