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 questions of evolution and migration, using clues hidden just under the enamel.
A group of McMaster University researchers reveals the potential of the method in a paper in Current Anthropology. In 2016, the researchers first established that dentine carries a permanent record of vitamin D deficiency, which is also called 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 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 people.
“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,” said Megan Brickley, PhD, a McMaster anthropologist and lead author of the paper.
Learn more about this study at Current Anthropology (2017); doi: 10.1086/691683.
Published by CDA Journal, Vol 45, N°7. July 2017.
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