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 Virtual Reality in Medicine: New Opportunities for Diagnostics and Surgical Planning
07.12.2016 | Universität Basel

nachricht 3-D printed kidney phantoms aid nuclear medicine dosing calibration
06.12.2016 | Society of Nuclear Medicine

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>