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:5/16/2016)... --  EyeLock LLC , a market leader of iris-based ... IoT Center of Excellence in Austin, Texas ... embedded iris biometric applications. EyeLock,s iris authentication ... with unmatched biometric accuracy, making it the most proven ... platform uses video technology to deliver a fast and ...
(Date:4/28/2016)... BANGALORE, India , April 28, 2016 ... subsidiary of Infosys (NYSE: INFY ), and Samsung ... global partnership that will provide end customers with a ... and payment services.      (Logo: http://photos.prnewswire.com/prnh/20130122/589162 ... for financial services, but it also plays a fundamental part ...
(Date:4/19/2016)... , UAE, April 20, 2016 ... implemented as a compact web-based "all-in-one" system solution for ... biometric fingerprint reader or the door interface with integration ... modern access control systems. The minimal dimensions of the ... readers into the building installations offer considerable freedom of ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... , June 23, 2016   EpiBiome , a ... $1 million in debt financing from Silicon Valley Bank ... automation and to advance its drug development efforts, as ... facility. "SVB has been an incredible strategic ... services a traditional bank would provide," said Dr. ...
(Date:6/23/2016)... ... , ... In a new case report published today in STEM CELLS Translational ... lymphedema after being treated for breast cancer benefitted from an injection of stem cells ... this debilitating, frequent side effect of cancer treatment. , Lymphedema refers to ...
(Date:6/23/2016)... LONDON , June 23, 2016 ... & Hematology Review, 2016;12(1):22-8 http://doi.org/10.17925/OHR.2016.12.01.22 ... Review , the peer-reviewed journal from touchONCOLOGY, ... the escalating cost of cancer care is placing ... a result of expensive biologic therapies. With the ...
(Date:6/23/2016)... ... 23, 2016 , ... Regulatory Compliance Associates® Inc. (RCA), a ... webinar on Performing Quality Investigations: Getting to Root Cause. This ... charge. , Incomplete investigations are still a major concern to the Regulatory Authorities ...
Breaking Biology Technology: