Featured Research

from universities, journals, and other organizations

Shedding new light on how jaws evolve

Date:
August 7, 2012
Source:
University of Notre Dame
Summary:
If you're looking for information on the evolution and function of jaws, a new integrative research program has some answers. Scientists are investigating major adaptive and morphological transformations in the mammalian musculoskeletal system during development and across higher-level groups.

Matt Ravosa with a llama.
Credit: Image courtesy of University of Notre Dame

If you're looking for information on the evolution and function of jaws, University of Notre Dame researcher Matt Ravosa is your man.

His integrative research program investigates major adaptive and morphological transformations in the mammalian musculoskeletal system during development and across higher-level groups. In mammals, the greater diversification and increasingly central role of the chewing complex in food procurement and processing has drawn considerable attention to the biomechanics and evolution of this system. Being among the most highly mineralized, and thus well-preserved, tissues in the body, craniodental remains have long been used to offer novel insights into the behavior and affinities of extinct organisms.

Ravosa feels that the study of mandibular symphysis, which is the midline joint between the left and right lower jaws, is one of the most interesting and complex articulations in the bodies of mammals. This is due to the remarkable evolutionary and postnatal variation in the degree of fusion, or the amount of hard versus soft tissue, in this joint. For instance, humans, apes and monkeys all have a bony symphysis, which differs from the condition observed in most other living and fossil primates.

In two papers about adaptive and non-adaptive influences on mandibular evolution with his postdoctoral fellow Jeremiah Scott, Ravosa and his colleagues present analyses based on more than 300 species and 2,900 individual mandibles from highly diverse mammal groups where the feeding behavior of living species is well-documented.

Ravosa is particularly interested in determining if there is a relationship between the properties of food being consumed and the degree of fusion of the jaw. His recent paper in the Journal of Evolutionary Biology is the most broad-based examination to date relating dietary properties of mammals to the degree of fusion. His research reveals that in the case of marsupials, carnivorans and strepsirrhine primates that eat harder, tougher and bigger foods have a lesser degree of fusion. By contrast, animals that consume softer, smaller foods do not have as great a degree of fusion. This supports biomechanical arguments that fusion strengthens the symphyseal joint during postcanine chewing and biting.

In another paper appearing in the journal Evolution, Ravosa reports that in some bat lineages, the fusing of the jaw can be evolutionarily constrained as its morphology does not vary as a function of dietary products. Such evidence about limits on musculoskeletal variation is typically rare in mammals, with these findings having important implications regarding the evolution of the feeding apparatus in humans and other anthropoids. Though dietarily diverse, all members of this primate group exhibit a fused symphysis that also does not vary with diet.

Ravosa notes that similar analysis of other species would further help our understanding of the evolution and development of the mammalian skull, which includes his lab's ongoing anatomical, imaging, cellular, molecular and engineering approaches to determinants of jaw-joint formation, aging and pathology.


Story Source:

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


Journal Reference:

  1. J. E. SCOTT, A. S. HOGUE, M. J. RAVOSA. The adaptive significance of mandibular symphyseal fusion in mammals. Journal of Evolutionary Biology, 2012; 25 (4): 661 DOI: 10.1111/j.1420-9101.2012.02457.x

Cite This Page:

University of Notre Dame. "Shedding new light on how jaws evolve." ScienceDaily. ScienceDaily, 7 August 2012. <www.sciencedaily.com/releases/2012/08/120807151316.htm>.
University of Notre Dame. (2012, August 7). Shedding new light on how jaws evolve. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2012/08/120807151316.htm
University of Notre Dame. "Shedding new light on how jaws evolve." ScienceDaily. www.sciencedaily.com/releases/2012/08/120807151316.htm (accessed October 20, 2014).

Share This



More Plants & Animals News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Goliath Spider Will Give You Nightmares

Goliath Spider Will Give You Nightmares

Buzz60 (Oct. 20, 2014) An entomologist stumbled upon a South American Goliath Birdeater. With a name like that, you know it's a terrifying creepy crawler. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
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


Plants & Animals

Earth & Climate

Fossils & Ruins

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