Navigation Links
Skin color: Handy tool for teaching evolution
Date:2/20/2011

Variations in skin color provide one of the best examples of evolution by natural selection acting on the human body and should be used to teach evolution in schools, according to a Penn State anthropologist.

"There is an inherent level of interest in skin color and for teachers, that is a great bonus -- kids want to know," said Nina Jablonski, professor and head, Department of Anthropology, Penn State. "The mechanism of evolution can be completely understood from skin color."

Scientists have understood for years that evolutionary selection of skin pigmentation was caused by the sun. As human ancestors gradually lost their pelts to allow evaporative cooling through sweating, their naked skin was directly exposed to sunlight. In the tropics, natural selection created darkly pigmented individuals to protect against the sun.

Ultraviolet B radiation produces vitamin D in human skin, but can destroy folate. Folate is important for the rapid growth of cells, especially during pregnancy, when its deficiency can cause neural tube defects. Destruction of folate and deficiencies in vitamin D are evolutionary factors because folate-deficient mothers produce fewer children who survive, and vitamin D-deficient women are less fertile than healthy women.

Dark skin pigmentation in the tropics protects people from folate destruction, allowing normal reproduction. However, because levels of ultraviolet B are high year round, the body can still produce sufficient vitamin D. As humans moved out of Africa, they moved into the subtropics and eventually inhabited areas up to the Arctic Circle. North or south of 46 degrees latitude -- Canada, Russia, Scandinavia, Western Europe and Mongolia -- dark-skinned people could not produce enough vitamin D, while lighter-skinned people could and thrived. Natural selection of light skin occurred.

The differences between light-skinned and dark-skinned people are more interesting than studying changes in the wing color o
'/>"/>

Contact: A'ndrea Elyse Messer
aem1@psu.edu
814-865-9481
Penn State
Source:Eurekalert

Page: 1 2 3

Related biology news :

1. Radiologists play key role in teaching physiology to medical students
2. Simple, ingenious way to create lab-on-a-chip devices could become a model for teaching and research
3. ASPBs Teaching Tools in Plant Biology receives Gold Award
4. Mississauga teacher awarded prize for excellence in teaching genomics
5. McMaster, NVIDIA establish first CUDA Teaching Centre in Canada
6. Teaching communication and information literacy skills
7. Ethical issues ignored in teaching, research of sustainability
8. American Sociological Association launches first-of-its-kind teaching tool
9. Physical education teaching staff play key role in making you like sport
10. UAB professors book promises solution for teaching evolution without conflict
11. K-State plant pathologists develop online teaching modules used globally
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/22/2014)... , Dec. 22, 2014  The 2014 Holiday Season ... as Acuity Market Intelligence reports that the long anticipated ... forecasts that intensifying demand for smart phones, tablets, and ... global market of 2.5 billion users with nearly 4.8 ...
(Date:12/19/2014)... , Dec. 18, 2014  23andMe, Inc., the leading personal genetics ... fine-scale differences in genetic ancestry of individuals from across ... first arrived more than four hundred years ago, ... place for peoples from different continents. This study illuminates how ...
(Date:12/17/2014)... Dec. 15, 2014 The Defense Logistics Agency is ... and prevent counterfeit microcircuits from entering into its supply ... in-house microcircuit anti-counterfeit initiative dubbed DNA marking. The capability ... their reliability throughout the supply chain. The new quality ...
Breaking Biology News(10 mins):First Season of Holiday Shopping with Mobile Biometric Payments Wraps Up With a Present for Biometrics Industry: A Rosy Forecast for More Than 2 Billion Users of 4.8 Billion Mobile Biometric Devices by 2020 223andMe Study Sketches Genetic Portrait of the United States 223andMe Study Sketches Genetic Portrait of the United States 323andMe Study Sketches Genetic Portrait of the United States 4Defense Logistics Agency Launches DNA Marking Capability to Strengthen Microcircuit Supply Chain 2Defense Logistics Agency Launches DNA Marking Capability to Strengthen Microcircuit Supply Chain 3
... first reported case in Asia of primate-to-human transmission of simian ... primates that so far has not been shown to cause ... monkey to a human took place at a monkey temple ... of the journal Emerging Infectious Diseases. Even though this particular ...
... States Department of Agriculture (USDA) has positively identified the pathogenic ... in Mongolia by field veterinarians from the Wildlife Conservation Society ... occurring in wild migratory birds with no apparent contact to ... for a health survey of wild bird populations in the ...
... modern oceanography is how animals in the deep sea ... Bay Aquarium Research Institute (MBARI) recently published a paper ... that live on the deep seafloor off the coast ... deep-sea video, Bruce Robison and his colleagues found that ...
Cached Biology News:Primate virus jumps species barrier to humans for first time in Asia 2Primate virus jumps species barrier to humans for first time in Asia 3Bird samples from Mongolia confirmed as H5N1 avian flu 2Bird samples from Mongolia confirmed as H5N1 avian flu 3'Sinkers' provide missing piece in deep-sea puzzle 2'Sinkers' provide missing piece in deep-sea puzzle 3'Sinkers' provide missing piece in deep-sea puzzle 4
(Date:1/22/2015)... | RBJ today announces the firm brokered a long-term lease ... leading biopharmaceutical company, at Two Ledgemont Center in ... , president, and Brian Cohen , senior vice president, ... at 95 Hayden Ave. Photo - http://photos.prnewswire.com/prnh/20150122/170765 ...
(Date:1/22/2015)... Protocol Networks brings independent technology consulting ... brand-neutral, independent consultants, Protocol Networks has recently announced its ... the years, his company has attracted several clients in ... as well as others. With the success of these ...
(Date:1/22/2015)... Wilmington, DE (PRWEB) January 22, 2015 ... the Pistoia Alliance, which helps companies check the legal ... set to expand to China. , As their ... companies are globally adopting software solutions built as a ...
(Date:1/22/2015)... 22. 2015  Varian Medical Systems (NYSE: VAR ), ... for its commitment to sustainability with inclusion on a prestigious ... highest ranked healthcare equipment company among the Corporate Knights Global ... Economic Forum at Davos, Switzerland . ...
Breaking Biology Technology:Transwestern | RBJ Advises Shire in 202,000 SF Lease, Creating Boston's Largest Suburban Biotech Campus 2Protocol Networks Brings Independent Technology Consulting to the Constitution State 2Global Compliance Service for Controlled Substances to Expand to China 2Varian Honored Among World's 100 Most Sustainable Corporations 2
... Madison, Wis. Can a Mac really be hacked in ... University of Wisconsin-Madison systems engineer, who criticized recent media reports for ... which the owner of a computer gave out login accounts to ... for someone who had been given access to the computer to ...
... last week's Fusion2006 was to make information ... that presenters delivered, private-sector CIOs would be well advised ... there was a dominant theme of the second annual ... linkage - linkage with their CEOs and linking information ...
... — Competition is heating up in Waukesha for ... residents. , ,Three firms want to build the infrastructure ... bandwidth to Internet service providers. After waiting several years ... city would start to receive royalties. , ,Midwest Fiber, ...
Cached Biology Technology:IT can't be separate from core business 2
... Rabbit polyclonal to MSY2/YBOX2 ( Abpromise ... Antigen: Synthetic peptide ... the C-terminus of Human MSY2/YBOX2. ... proprietary) (Peptide available ...
...
Request Info...
Purified Mouse anti-Hu LAT (pY226) Storage Temperature: Refrigerate(2 to 8C)...
Biology Products: