The global genealogy industry is booming, with people’s desire to find out if they have some long-lost Viking blood outweighing concerns over privacy and marketing. Adam Elliott Segal deftly interweaves his personal story in this look at the success of consumer DNA kits.

For the dozens of black-market babies I’ve interviewed over the years, submitting a saliva sample or simply making their birth story public wasn’t a philosophical or moral question. It was the only way to get answers.