Seattle – Mind Foster reports that women retain and carry living DNA from every man with whom they have sexual intercourse, according to a new study by the University of Seattle and the Fred Hutchinson Cancer Research Center. The study, which discovered the startling information by accident, was originally trying to determine if women who have been pregnant with a son might be more predisposed to certain neurological diseases that occur more frequently in males. The study found that female brains often harbor “male microchimerism,” or in other words, the presence of male DNA that originated from another individual and are genetically distinct from the cells that make up the rest of the woman. According to the study: “63% of the women (37 of 59) tested harbored male microchimerism in the brain. Male microchimerism was present in multiple brain regions.”

The researchers wanted to know where the male DNA came from and determined that the possible sources of the male DNA cells living in the women’s brains are: an abortion the woman didn’t know about; a male twin that vanished; an older brother transferred by the maternal circulation; and sexual intercourse. The first three options apply to a very small percentage of women. They couldn’t possibly account for the 63% figure. The fourth option? It’s rather more common. Sex. This has very important ramifications for women. Every male a woman absorbs spermatozoa from becomes a living part of her for life.

However, Suzanne Sadedin, Ph.D. in evolutionary biology, disputes this claim in Forbes. She queries, do women retain DNA from every man they have ever slept with? No. Where did the cells come from? Dr. Sadedin says that the most likely explanation is pregnancy. During implantation, embryonic cells are programmed to divide extremely fast and invade the mother’s bloodstream. Sometimes, they can establish populations in other parts of her body that survive for the rest of her life. Why do some women who’ve never been pregnant still have male cells? Most likely they had been pregnant, they just didn’t know it. There are also two other plausible sources for these cells: (1) cells from an older brother that had been retained in the woman’s mother were incorporated by the woman when she was growing in the womb or (2) cells from a male twin that was absorbed before birth. It’s remotely possible that women might sometimes retain some non-sperm cells from male partners, since that’s never been studied and biology is weird. But there’s currently no reason to think it’s true, and many reasons to think it’s not. (Find the full articles at Mind Foster at Mindfoster.co/1129/women-retain-and-carry-living-dna-from-every-man-with-whom-theyve-made-love-with/ and Forbes.com/sites/quora/2017/08/15/male-dna-is-often-found-in-womens-brains-where-does-it-come-from/#3c65d5d17459)