Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Novel technique offers new look at ancient diet dogma

05.08.2005


A Penn State researcher is part of the team that developed techniques that have generated insights into dietary divergences between some of our human ancestors, allowing scientists to better understand the evolutionary path that led to the modern-day diets that humans consume. "Our new techniques are allowing us to get beyond simple dichotomies and helping us understand the processes by which dietary evolution is working," said Peter Ungar, professor of anthropology at the University of Arkansas.

Ungar and Robert Scott, postdoctoral fellow at the University of Arkansas, with colleagues at the Worcester Polytechnic Institute, State University of New York at Stony Brook, Johns Hopkins University School of Medicine and Penn State University, report their findings in the August 4, 2005 issue of the journal Nature.

The researchers, including Dr. Alan Walker, Evan Pugh Professor of Biological Anthropology and Biology, Penn State, investigated microscopic wear on the teeth of two species of ancient hominims – Australopithecus africanus, which lived between 3.3 and 2.3 million years ago, and Paranthropus robustus, which lived between 2 and 1.5 million years ago. The pits and scratches found on the teeth offer a visual history of the type of food consumed by the tooth’s owner. Pits indicate a diet of hard, brittle foods, like nuts and seeds, while scratches imply a diet of tough foods, like leaves and possibly meat.

Traditional examinations of these ancient teeth – counting pits and lines on a black and white electron micrograph image – suggested that A. africanus ate tough foods and P. robustus dined on hard, brittle fare. However, the researchers used a new technique developed by Ungar and his colleagues that combines engineering software, scale-sensitive fractal analysis and a scanning confocal microscope to create a reproducible texture analysis for teeth – and the analysis tells a more complete story.

The researchers looked at both roughness, or complexity, and directionality in the teeth they examined.

"Since food objects interact with teeth, we have different kinds of complexity in different diets. Directionality also correlates with diet," Scott said. Hard foods like nuts and seeds tend to lead to more complex tooth profiles, while tough foods like leaves lead to more scratches, which corresponds with directionality.

The confocal microscope and engineering software allow the researchers to take three-dimensional coordinates of the entire tooth and form a detailed image of the surface. When these images are combined, they can use fractal analysis to examine patterns in the tooth wear. The analysis showed that the two species had significant amounts of overlap in their diets and that while P. robustus had more complexity in its tooth wear, indicating that it ate more hard and brittle foods than A. africanus, it ate tough foods as well.

The researchers believe that this indicates that the species frequently ate the same types of foods, but that in times of scarcity or seasonal changes, P. robustus changed its diet to include foods that differed from those of A. africanus.

"The difference in their evolution in terms of diet is not driven by their preferences, but by scarcity," Ungar said. "It gives you a whole new way of thinking about dietary adaptation."

The researchers credit the new method of examining microscopic wear on teeth with allowing them to gain new insights into dietary evolution. "The old technique was subject to observer error, so we couldn’t get a handle on whether the variation we observed was real or the result of observer error in data acquisition," Ungar said. "The new technique is free of subjective observer error, so the variation we see is real. This allows us to actually look at within-species variation. We can finally get beyond ’these differed’ and start to understand how much they differed and overlapped, and what this means in terms of their adaptations and evolution."

"This technique does the same thing as finding new fossils," Scott said. The researchers examined the teeth, approached the pits and scratches with a new technique and drew new conclusions from the data. "We can say things that we could never say before," he said.

A’ndrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu

More articles from Medical Engineering:

nachricht An LED-based device for imaging radiation induced skin damage
30.03.2017 | The Optical Society

nachricht A Challenging European Research Project to Develop New Tiny Microscopes
28.03.2017 | Technische Universität Braunschweig

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

'On-off switch' brings researchers a step closer to potential HIV vaccine

30.03.2017 | Health and Medicine

Penn studies find promise for innovations in liquid biopsies

30.03.2017 | Health and Medicine

An LED-based device for imaging radiation induced skin damage

30.03.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>