News & AnalysisEvolution

How Sweet It Is: Genes Show How Bacteria Colonized Human Teeth

Science  22 Feb 2013:
Vol. 339, Issue 6122, pp. 896-897
DOI: 10.1126/science.339.6122.896

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Summary

When humans invented farming 10,000 years ago, they weren't the only ones to get a boost from the new starchy diet. Some microbes that had lurked at low levels in the mouths of hunter-gatherers bloomed on the sugary films coating the teeth of farmers who munched cereal grains. Eventually the cavity-causing Streptococcus mutans, for one, took root. It adapted to the sweet life, multiplying like a weed and edging out many other species of bacteria. That leaves the modern mouth a depauperate ecosystem, according to two new genetic studies.