Your genes define your starting point in life: nature versus nurture comes after, building on top. But as Carl Zimmer writes in the New York Times, the idea of this singular genetic “you,” that’s built up of cells carrying “your genes” is, upon closer inspection, kind of wooly. Especially if you’re a mother.
After a baby is born, it may leave some fetal cells behind in its mother’s body, where they can travel to different organs and be absorbed into those tissues. “It’s pretty likely that any woman who has been pregnant is a chimera,” Dr. Randolph said.
The genomes of your kids may be driving cells all over your body. In a study that analyzed the cells of women’s brains, says Zimmer, scientists “found neurons with Y chromosomes in 63 percent of them. The neurons likely developed from cells originating in their sons.”