An African strontium map sheds light on the origins of enslaved people
Pinpointing birthplaces based on dental records can deepen understanding of the slave trade

From the 15th to the 19th centuries, more than 12 million Africans were enslaved and sent to the Americas and Europe. Combining dental records with a map of strontium ratios across sub-Saharan Africa is allowing researchers to pinpoint some slaves' birthplaces.
Joseph Swain/Wikimedia Commons