Tracing ancient genes
Prehistoric Europe was home to hunter-gatherers until migrating farmers muscled them out. Genetic information teased from ancient skeletons is helping scientists reconstruct this saga, as Tina Hesman Saey reported in “Written in bone” (SN: 5/17/14, p. 26).
Sometimes, untangling genetic history can be a little one-sided. Researchers often rely on mitochondrial DNA, passed on only from the mother. As Debra Baker noted, this presents a problem: “Couldn’t the lack of similarity of mitochondrial DNA among the different groups arise because they all were matrilineal?” she asked in an e-mail. “Instead of group isolation as suggested by the article, there could have been interbreeding, but the child would have remained in the mother’s group.”