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:4/26/2016)... LONDON , April 26, 2016 /PRNewswire/ ... Systems, a product subsidiary of Infosys (NYSE: ... partnership to integrate the Onegini mobile security platform ... http://photos.prnewswire.com/prnh/20151104/283829LOGO ) The integration ... security to access and transact across channels. Using ...
(Date:4/15/2016)... April 15, 2016  A new partnership announced ... accurate underwriting decisions in a fraction of the ... priced and high-value life insurance policies to consumers ... With Force Diagnostics, rapid testing (A1C, Cotinine ... readings (blood pressure, weight, pulse, BMI, and activity ...
(Date:4/13/2016)...  IMPOWER physicians supporting Medicaid patients in ... standard in telehealth thanks to a new partnership with ... IMPOWER patients can routinely track key health measurements, such ... and, when they opt in, share them with IMPOWER ... local retail location at no cost. By leveraging this ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... DIEGO , June 24, 2016 ... more sensitively detects cancers susceptible to PARP inhibitors ... circulating tumor cells (CTCs). The new test has ... HRD-targeted therapeutics in multiple cancer types. ... targeting DNA damage response pathways, including PARP, ATM, ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... announce the launch of their brand, UP4™ Probiotics, into Target stores nationwide. The ... is proud to add Target to its list of well-respected retailers. This list ...
(Date:6/23/2016)... , June 23, 2016 Houston Methodist ... the Cy-Fair Sports Association to serve as their ... agreement, Houston Methodist Willowbrook will provide sponsorship support, ... connectivity with association coaches, volunteers, athletes and families. ... the Cy-Fair Sports Association and to bring Houston ...
(Date:6/23/2016)... FRANCISCO , June 23, 2016   EpiBiome ... has secured $1 million in debt financing from Silicon ... ramp up automation and to advance its drug development ... its new facility. "SVB has been an ... beyond the services a traditional bank would provide," said ...
Breaking Biology Technology: