Navigation Links
What shapes a bone?
Date:8/5/2011

Researchers at Johns Hopkins found that use over time and not just genetics informs the structure of jaw bones in human populations. The researchers say these findings may be used to predict the diet of an ancient population, even if little evidence exists in the fossil record. It can also make it easier for scientists to pinpoint the genetic relationship between fossils.

Their results were published online June 23 in the American Journal of Physical Anthropology.

"Our research aimed to see how much of the mandible'sor jaw bone'sshape is plastic, a response to environmental influences, such as diet, and how much is genetic. We used archaeological jaw bones from two different regions to answer that question," explains Megan Holmes, graduate student at the Johns Hopkins Center for Functional Anatomy and Evolution, and lead author of the paper. "Before we can make inferences about what the shape of a bone tells us, like what environment the individual lived in, who it's related to or what it ate, we have to understand what creates that shape. The idea that function influences the shape of jaw bones is great for the archeological record in terms of discovering the diet of a population, and it's also really useful for reconstructing the fossil recordfinding which fossils are related to which, and how."

The group chose to study the Arikara and Point Hope American Indian populations, since they were genetically isolated from other groups and ate different diets. They investigated bones from the regions dating back to the 1600s and 1700s, times for which the diets are known from other records. The Point Hope population in Alaska ate a "hard" diet that included tough dried meat. They also used their teeth for a variety of nonfood-related tasks, such as stripping leather. The Arikara, from the Dakota area of the United States, ate a softer diet, which consisted of farming supplemented with light hunting.

The researchers precisely measured jaw bones from 63 members of the Point Hope population and 42 individuals from the Arikara population using an X-ray gun as well as calipers, and they used those measurements to extrapolate the proportions of the entire jaw. "The jaw bones were similar in children before they were old enough to start chewing, but different in adulthood, which implies that this divergence is likely a functional result of their diet and the use of their jaw, rather than genetics," says Holmes.

The changes to the jaw bones were explained using a theory drawn from engineering, which directly relates the geometry of a bone to the stresses put on it during use. The team was able to investigate very specific parts of the jaw bones and relate them to specific dietary habits. In the Point Hope population, for example, they found round, wide jaw bonesa result of having to exert more force to chew a harder diet. The Arikara, on the other hand, did not show this expansion, which they attributed to the lighter chewing requirement of a softer diet.

"Genetics creates a blueprint of the bone, but a lot of things influence the bone's construction," says Holmes. "Mechanical pressure from muscle stress and strain from day-to-day activities can remodel the bone's surface and internal structure. Knowing how much the shape of a mandible we find is related to diet and how much genetically connects it to fossils found elsewhere can really help us parse out the family tree."


'/>"/>

Contact: Vanessa McMains
vmcmain1@jhmi.edu
410-502-9410
Johns Hopkins Medical Institutions
Source:Eurekalert  

Related biology news :

1. Seals sense shapes using their whiskers to feel wakes
2. Syracuse University research team shapes cell behavior research
3. Researchers discover new shapes of microcompartments
4. The lock shapes the key
5. Scientists clock on to how sunlight shapes daily rhythms
6. Oil spill reshapes sweeping new study of oyster reefs -- Virginia to Florida
7. Study finds that long-distance migration shapes butterfly wings
8. Yes, ecology shapes evolution, but guppies show reverse also true
9. Caltech and UCSD researchers shed light on how proteins find their shapes
10. Grape shapes
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
What shapes a bone?
(Date:2/2/2016)... 2, 2016 Technology Enhancements Accelerate Growth of X-ray ... the digital and computed radiography markets in ... Indonesia (TIM). It provides an ... as well as regional market drivers and restraints. The ... penetration and market attractiveness, both for digital and computed ...
(Date:2/1/2016)... 1, 2016 Rising sales of ... global touchfree intuitive gesture control market size ... sales of consumer electronics coupled with new technological advancements ... size through 2020   --> ... new technological advancements to drive global touchfree intuitive gesture ...
(Date:1/28/2016)... JOSE, Calif., Jan. 28, 2016 Synaptics (NASDAQ: SYNA ... results for its second quarter ended December 31, 2015. ... second quarter of fiscal 2016 increased 2 percent compared to the ... second quarter of fiscal 2016 was $35.0 million, or $0.93 per ... Non-GAAP net income for the first quarter of fiscal 2016 grew ...
Breaking Biology News(10 mins):
(Date:2/9/2016)... ... February 09, 2016 , ... Tunnell Consulting, Inc. announced that ... Paris, he will focus on acquiring new accounts and work closely with existing Tunnell ... , “Fred brings to our European clients more than 15 years of experience in ...
(Date:2/9/2016)... ... February 09, 2016 , ... PharmApprove ... for the National Organization for Rare Disorders (NORD). Dorman will lead PharmApprove efforts ... are heard throughout the drug regulatory review process. , “Adding Diane Dorman is ...
(Date:2/9/2016)... LONDON , February 9, 2016 ... replace paper and protect IP   E-WorkBook ... will be rolled out in Germany ... and protect valuable IP. Users will be able to search ... or experiment as part of the application, to boost collaboration ...
(Date:2/9/2016)... Feb. 9, 2016 ... 2016", report provides in depth insights on ... around the Protein-Tyrosine Phosphatase 1B (PTP1B) Inhibitors. ... in various stages of development including Discovery, ... III and Preregistration. Report covers the product ...
Breaking Biology Technology: