Featured Research

from universities, journals, and other organizations

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

Date:
January 24, 2014
Source:
University of Notre Dame
Summary:
A new study offers surprising insights into dietary influences on the growing skull.

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.

Related Articles


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.


Story Source:

The above story is based on materials provided by University of Notre Dame. The original article was written by William G. Gilroy. Note: Materials may be edited for content and length.


Journal Reference:

  1. J. E. Scott, K. R. McAbee, M. M. Eastman, M. J. Ravosa. Experimental perspective on fallback foods and dietary adaptations in early hominins. Biology Letters, 2014; 10 (1): 20130789 DOI: 10.1098/rsbl.2013.0789

Cite This Page:

University of Notre Dame. "New study changes conceptions about the determinants of skull development and form." ScienceDaily. ScienceDaily, 24 January 2014. <www.sciencedaily.com/releases/2014/01/140124161237.htm>.
University of Notre Dame. (2014, January 24). New study changes conceptions about the determinants of skull development and form. ScienceDaily. Retrieved January 31, 2015 from www.sciencedaily.com/releases/2014/01/140124161237.htm
University of Notre Dame. "New study changes conceptions about the determinants of skull development and form." ScienceDaily. www.sciencedaily.com/releases/2014/01/140124161237.htm (accessed January 31, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Saturday, January 31, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC: Get Vaccinated for Measles

CDC: Get Vaccinated for Measles

Reuters - US Online Video (Jan. 30, 2015) The CDC is urging people to get vaccinated for measles amid an outbreak that began at Disneyland and has now infected more than 90 people. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Obama To Outline New Plan For Personalized Medicine

Obama To Outline New Plan For Personalized Medicine

Newsy (Jan. 30, 2015) President Obama is expected to speak with drugmakers Friday about his Precision Medicine Initiative first introduced last week. Video provided by Newsy
Powered by NewsLook.com
NFL Concussions Down; Still on Parents' Minds

NFL Concussions Down; Still on Parents' Minds

AP (Jan. 30, 2015) The NFL announced this week that the number of game concussions dropped by a quarter over last season. Still, the dangers of the sport still weigh on players, and parents&apos; minds. (Jan. 30) Video provided by AP
Powered by NewsLook.com
U.S. Wants to Analyze DNA from 1 Million People

U.S. Wants to Analyze DNA from 1 Million People

Reuters - US Online Video (Jan. 30, 2015) The U.S. has proposed analyzing genetic information from more than 1 million American volunteers to learn how genetic variants affect health and disease. Rough Cut (no reporter narration). Video provided by Reuters
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


Health & Medicine

Mind & Brain

Living & Well

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