PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

New study changes conceptions about the determinants of skull development and form

2014-01-25
(Press-News.org) Contact information: Matthew Ravosa
Matthew.J.Ravosa.1@nd.edu
574-631-2556
University of Notre Dame
New study changes conceptions about the determinants of skull development and form A new study by a team of researchers led by Matthew Ravosa, professor of biological sciences and concurrent professor of aerospace and mechanical engineering and anthropology at the University of Notre Dame, offers surprising insights into dietary influences on the growing skull.

Ravosa notes that the robust jaws and large, thick-enameled molars of the first human ancestors from Africa, known as australopiths, have longbeen interpreted as adaptations for hard object feeding, especially in the genus Paranthropous robustus, and to a lesser extent, Australopithecus.

Recent studies of molar surface microware indicate that only Paranthropous robustus regularly ate hard items, suggesting that the oral anatomy of other australopiths reflected rare, seasonal exploitations of hard fallback foods. Fallback foods are typically more mechanically challenging than diets exploited on a more annual basis are critical to survive seasonal periods when easier to process preferred resources are scarce. The ecological and morphological importance of fallback foods have been implicated in a number of recent studies of living and fossil mammals.

"In contrast to this highly influential hypothesis about australopith feeding adaptations, our study demonstrated that hard object feeding cannot explain the extreme morphology of Paranthropous boisei," Ravosa said. "Rather, analysis of long-term dietary plasticity in an animal model, in this case rabbits, suggests year-round reliance on tough foods requiring prolonged post-canine processing in Paranthropous boisei. Increased consumption of such food items may have marked the transition from the earlier hominids Ardipithecus to Australopithecus, with routine hard object feeding in Paranthropous robustus representing a novel behavior."

The researchers used a sample which contained 30 five-week-old weanling male rabbits divided equally into three dietary cohorts and raised for 48 weeks.

Prior research in Ravosa's lab has focused on diet-induced plasticity in the skull and feeding complex in in growing rabbits and rodents. These kinds of studies are important for evaluating the functional significance of various craniofacial features, particularly those less accessible via more direct in vivo approaches, as well as for unraveling the feeding behavior of extinct species.

"However, prior to our present investigation, we'd not been able to track dietary influences on the growing skull in the same individual (i.e., longitudinally), we'd not modeled seasonal variation in dietary properties, and we'd not tracked dietary effects for an entire year (i.e., from weaning until middle age)," Ravosa said. "These aspects of our study were novel vs. all other such work (in our lab and elsewhere) and facilitated a more naturalistic perspective on ecological determinants of postnatal and evolutionary changes in mammalian skull form. By being able to track the extent to which morphological changes in the cranium track (or do not track) dietary changes, we were also able to evaluate the extent to which skeletal structure can be used to infer behavior in the fossil record, a common assumption that surprisingly is largely untested.

"While my lab has long focused on functional determinants of phenotypic variation in skull form in primate and non-primate mammals, it has rarely focused on human evolution. However, as the notion that seasonal variation in the presence of hard/tough diets explains the robust jaws and teeth of early human ancestors (australopiths) has become widely accepted, our rabbit study is of particularly unique relevance for addressing such outstanding questions."

Ravosa was the principal investigator for the study and the research team included postdoctoral fellow Jeremiah Scott, now a faculty member at Southern Illinois University, senior research technician Kevin McAbee, and former Notre Dame undergraduate researcher Meghan Eastman. The study appears in the journal Biology Letters.

INFORMATION:

END



ELSE PRESS RELEASES FROM THIS DATE:

Maternal-fetal medicine professionals identify ways to reduce first cesarean

2014-01-25
WASHINGTON--A recently published article, based on a workshop, Preventing the First Cesarean ...

Researchers use sensory integration model to understand unconscious priming

2014-01-25
PITTSBURGH—Priming, an unconscious phenomenon that causes the context of information to change the way we think or behave, has frustrated scientists as they have unsuccessfully attempted to understand ...

Do patient decision support interventions lead to savings? A systematic review

2014-01-25
Publicity surrounding the implementation of patient decision support interventions (DESIs) traditionally focuses on two areas of improvement: helping patients make ...

Impulsive personality linked to food addiction

2014-01-25
Athens, Ga. – The same kinds of impulsive behavior that lead some people to abuse alcohol and other drugs may also be an important contributor to an unhealthy relationship with food, according to new research from the ...

Scientists develop powerful new animal model for metastatic prostate cancer

2014-01-25
Cold Spring Harbor, NY – Prostate cancer is the most common form of cancer in men. Affecting ...

University of Hawaii scientists make a big splash

2014-01-25
Researchers from the University of Hawaii – Manoa (UHM) School of Ocean and Earth Science and Technology (SOEST), Lawrence Livermore ...

From one cell to many: How did multicellularity evolve?

2014-01-25
In the beginning there were single cells. Today, many millions of years later, most plants, animals, ...

Carbon dioxide paves the way to unique nanomaterials

2014-01-24
In common perception, carbon dioxide is just a greenhouse gas, one of the major environmental problems of mankind. For Warsaw chemists CO2 became, however, something ...

Material developed could speed up underwater communications by orders of magnitude

2014-01-24
University of California, San Diego electrical engineering professor Zhaowei Liu and colleagues have taken the first steps in a project to develop fast-blinking ...

Scientists reveal why life got big in the Earth's early oceans

2014-01-24
Why did life forms first begin to get larger and what advantage did this increase in size provide? UCLA biologists working with an international team of scientists examined the ...

LAST 30 PRESS RELEASES:

Henna’s hidden healing: Treating fibrosis with a chemical derived from Lawsonia inermis

KIST demonstrates world's first ultra-precise, ultra-high-resolution distributed quantum sensor with 'entangled light'

Liver transplantation utilizing grafts donated after medical assistance in dying is feasible and has outcomes comparable to standard donation

Canada is failing the rising numbers of youth who use opioids

Opioid prescribing for pain is declining in Canada

Can inpatient care help address overdose crisis?

Discovering six new bat species is a treat for museum researchers

National emergency wakeup call as SEND support system crisis worsens – latest analysis shows

New drug-eluting balloon may be as safe and effective as conventional metal stents for repeat percutaneous coronary interventions

Effectiveness and cost-effectiveness of automated external defibrillators in private homes

University of Phoenix College of Social and Behavioral Sciences leadership publishes white paper on trauma-informed education

Microbial iron mining: turning polluted soils into self-cleaning reactors

Molecular snapshots reveal how the body knows it’s too hot

Analysis finds alarming rise in severe diverticulitis among younger Americans

Mitochondria and lysosomes reprogram immune cells that dampen inflammation

Cockroach infestation linked to home allergen, endotoxin levels

New biochar-powered microbial systems offer sustainable solution for toxic pollutants

Identifying the best high-biomass sorghum hybrids based on biomass yield potential and feedstock quality affected by nitrogen fertility management under various environments

How HIV’s shape-shifting protein reveals clues for smarter drug design

Study identifies viral combinations that heighten risk of severe respiratory illnesses in infants

Aboveground rather than belowground productivity drives variability in miscanthus × giganteus net primary productivity

Making yeast more efficient 'cell factories' for producing valuable plant compounds

Aging in plain sight: What new research says the eyes reveal about aging and cardiovascular risk

Child welfare system involvement may improve diagnosis of developmental delays

Heavier electric trucks could strain New York City’s roads and bridges, study warns

From womb to world: scientists reveal how maternal stress programs infant development

Bezos Earth Fund grants $2M to UC Davis and American Heart Association to advance AI-designed foods

Data Protection is transforming humanitarian action in the digital age, new book shows

AI unlocks the microscopic world to transform future manufacturing

Virtual reality helps people understand and care about distant communities

[Press-News.org] New study changes conceptions about the determinants of skull development and form