Navigation Links
University of Tennessee anthropologists find American heads are getting larger
Date:5/30/2012

White Americans' heads are getting bigger. That's according to research by forensic anthropologists at the University of Tennessee, Knoxville.

Lee Jantz, coordinator of UT's Forensic Anthropology Center (FAC); Richard Jantz, professor emeritus and former director of the FAC; and Joanne Devlin, adjunct assistant professor, examined 1,500 skulls dating back to the mid-1800s through the mid-1980s. They noticed U.S. skulls have become larger, taller and narrower as seen from the front and faces have become significantly narrower and higher.

The researchers cannot pinpoint a reason as to why American head shapes are changing and whether it is primarily due to evolution or lifestyle changes.

"The varieties of changes that have swept American life make determining an exact cause an endlessly complicated proposition," said Lee Jantz. "It likely results from modified growth patterns because of better nutrition, lower infant and maternal mortality, less physical work, and a breakdown of former ethnic barriers to marriage. Which of these is paramount we do not know."

The researchers found that the average height from the base to the top of the skull in men has increased by eight millimeters (0.3 inches). The skull size has grown by 200 cubic centimeters, a space equivalent to a tennis ball. In women, the corresponding increases are seven millimeters and 180 cubic centimeters.

Skull height has increased 6.8 percent since the late 1800s, while body height has increased 5.6 percent and femur length has only increased about 2 percent. Also, skull-height has continued to change whereas the overall heightening has recently slowed or stopped.

The scientists also noted changes that illustrate our population is maturing sooner. This is reflected in the earlier closing of a separation in the bone structure of the skull called the spheno-occipital synchondrosis, which in the past was thought to fuse at about age twenty. Richard Jantz and Natalie Shirley, an adjunct assistant professor in the FAC, have found the bone is fusing much earlier 14 for girls and 16 for boys.

America's obesity epidemic is the latest development that could affect skeletal shape but its precise effects are unclear.

"This might affect skull shape by changing the hormonal environment, which in turn could affect timing of growth and maturation," said Richard Jantz. "We know it has an effect on the long bones by increasing muscle attachment areas, increasing arthritis at certain joints, especially the knee, and increasing the weight bearing capacity."

The research only assessed Americans of European ancestry because they provided the largest sample sizes to work with. Richard Jantz said changes in skeletal structure are taking place in many parts of the world, but tend to be less studied. He said research has uncovered shifts in skull shape in Europe though it is not as dramatic as seen in the U.S.

The findings were presented on April 14 in Portland, Ore. at the annual meeting of the American Association of Physical Anthropologists.


'/>"/>

Contact: Whitney Heins
wheins@utk.edu
865-974-5460
University of Tennessee at Knoxville
Source:Eurekalert

Related biology news :

1. Rice University establishes National Corrosion Center
2. Case Western Reserve University researchers track Chernobyl fallout
3. Case Western Reserve University project ties soil conservation and river management together
4. Brown University and Women & Infants Hospital expand national childrens study to Bristol County
5. NIH selects Case Western Reserve University to participate in National Childrens Study
6. US Senate confirms Clemson University engineering Dean Esin Gulari to National Science Board
7. University professor stresses links between US Navy sonar and whale strandings
8. Scent on demand: Hebrew University scientists enhance the scent of flowers
9. University success at national engineering awards
10. University of Leicester professor adds new perspective to rainforest debate
11. Providing toilets, safe water is top route to reducing world poverty: UN University
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/13/2017)... Former 9/11 Commission border counsel and Special Counsel to ... of Identity Strategy Partners, LLP, today releases the following ... Protecting the Nation From Foreign Terrorist Entry Into the ... Trump,s ,Travel Ban, Executive Order gains more notoriety and ... ban, it is important that our national discourse regain ...
(Date:2/8/2017)... , Feb. 8, 2017 About Voice Recognition ... to match it against a stored voiceprint template. ... pitch, cadence, and tone are compared to distinguish ... hardware installation, as most PCs already have a ... transactions. Voice recognition biometrics are most likely to ...
(Date:2/8/2017)... 2017 The biometrics market has reached ... of organizations, desires to better authenticate or identify ... and challenge questions), biometrics is quickly working its ... market is driven by use cases, though there ... enterprise uses cases, with consumer-facing use cases encompassing ...
Breaking Biology News(10 mins):
(Date:2/21/2017)... ... February 21, 2017 , ... Vortex ... , a fully automated benchtop system for collecting intact circulating tumor cells (CTCs) ... at the Molecular Medicine Tri Conference (Tri-Con) Annual Meeting 2017 (February 19–24 San ...
(Date:2/21/2017)... ... 21, 2017 , ... The medical potential of stem cells is both extensive ... medicine, due to their differentiating characteristics. Stem cells are unique as the have the ... induced to become tissue or organic-specific cells with special functions. , Stem cell ...
(Date:2/21/2017)... ... 2017 , ... Creation Technologies, a private company and 25-year ... (OEMs) , today announced it has received the ‘Highest Overall Customer Rating’ Service ... category of electronics manufacturing services (EMS) providers with annual revenues over $500 million. ...
(Date:2/21/2017)... --  Logicalis Healthcare Solutions , the healthcare-focused practice within ... provider ( www.us.logicalis.com ), today announced a new service ... service will help hospital CIOs make the best use ... and other clinicians immediate access to a pool of ... hospital IT staff to focus on broader issues such ...
Breaking Biology Technology: