"In our human species there have long been born a few individuals neither fully male nor female, but it was until recently a very few indeed. I cannot recollect any such individuals among my fellow pupils at school, nor in my intake for National Service in 1949, nor so far as I know among my children's generation at school.
Evolutionary change seldom comes so suddenly or across such a wide front, so I think it is time we had some research into the extent of the phenomenon both in time and geographical reach. I do not know if the populations of third world or of urban or of rural societies are more or less affected.
Nor is it known if it is only our species or others living alongside us which have been affected, but that knowledge might point to a trigger such as pollution, which is the belief of some scientists."