A controversial new theory depicts pregnancy not as a harmonious relationship between the pregnant mother and the fetus she is carryng but as a struggle over the nutrients she will provide.
His theory also explains a baffling feature of developing fetuses: the copies of some genes are shut down, depending on which parent they come from. Dr. Haig has also argued that the same evolutionary conflicts can linger on after birth and even influence the adult brain. New research has offered support to this idea as well. By understanding these hidden struggles, scientists may be able to better understand psychological disorders like depression and autism.” (New York Times )
Haig argues that evolutionary selection should favor fetuses the invasiveness of whose sprouting placental blood vessels is more effective in wresting nutrients from their hosts, while mothers who restrain the incursion to have several successful pregnancies to spread their genes would similarly have an advantage. This theory appealingly explains the baffling condition of late-pregnancy high blood pressure called pre-eclampsia, which affects around 6% of pregnancies, as an extreme version of this struggle in which the fetus causes maternal hypertension to pump more blood in through the relatively low-pressure placenta. But be sure to read to the end of the article for the even more intriguing discussion of how this maternal-fetal conflict, played out in the arena of control of fetal gene expression, may shape the offspring’s behavior and social functioning postnatally.
