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Tooth truth: Human teeth tell the story of humanity through our fragile relationship with the sun

Date:
May 18, 2017
Source:
McMaster University
Summary:
Researchers have developed a new method to read imperfections in teeth caused by a lack of sunlight, creating a powerful tool to trace events ranging from human evolution and migration out of Africa to the silent damage of vitamin D deficiency that continues to affect 1 billion worldwide.
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These are teeth from Megan Brickley's lab at McMaster University.
Credit: McMaster University

The story of humanity's vital -- and fragile -- relationship with the sun has been locked inside our teeth for hundreds of thousands of years. A new method is starting to tease out answers to major questions of evolution and migration, using clues hidden just under the enamel.

A group of McMaster University researchers, working with colleagues in Quebec and France, reveals the potential of the method in a paper in Current Anthropology.

"This is exciting because we now have a proven resource that could finally bring definitive answers to fundamental questions about the early movements and conditions of human populations -- and new information about the importance of vitamin D for modern populations," says McMaster anthropologist Megan Brickley, lead author of the paper and Canada Research Chair in the Bioarchaeology of Human Disease.

In 2016, the researchers first established that dentine -- the material that forms the bulk of the tooth -- carries a permanent record of Vitamin D deficiency, or rickets. During periods of severe deficiency, new layers of dentine cannot mineralize, leaving microscopic markers scientists can read like rings of a tree.

Those markers can tell the story of human adaptation as early man moved from equatorial Africa into lower-light regions, and may explain changes in skin pigmentation to metabolize more sunlight, or how indoor living has silently damaged human health.

Until now, there has been no reliable way to measure vitamin D deficiency over time. As the authors show with examples from ancient and modern teeth, the method is valuable for understanding a health condition that today affects more than 1 billion.


Story Source:

Materials provided by McMaster University. Original written by Wade Hemsworth. Note: Content may be edited for style and length.


Journal Reference:

  1. Megan B. Brickley, Lori D’Ortenzio, Bonnie Kahlon, Annabelle Schattmann, Isabelle Ribot, Emeline Raguin, Benoit Bertrand. Ancient Vitamin D Deficiency: Long-Term Trends. Current Anthropology, 2017; 000 DOI: 10.1086/691683

Cite This Page:

McMaster University. "Tooth truth: Human teeth tell the story of humanity through our fragile relationship with the sun." ScienceDaily. ScienceDaily, 18 May 2017. <www.sciencedaily.com/releases/2017/05/170518140323.htm>.
McMaster University. (2017, May 18). Tooth truth: Human teeth tell the story of humanity through our fragile relationship with the sun. ScienceDaily. Retrieved May 27, 2017 from www.sciencedaily.com/releases/2017/05/170518140323.htm
McMaster University. "Tooth truth: Human teeth tell the story of humanity through our fragile relationship with the sun." ScienceDaily. www.sciencedaily.com/releases/2017/05/170518140323.htm (accessed May 27, 2017).

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