I remember reading an article a few years back that it is possible to select Y-chromosomes carrying sperm cells, has the X cells are slightly bigger. So, hopefully it was just a matter of having someone, over a microscope, doing a pre-selection.
As a side-note anecdote: men that board radar ships have a sharp decline of Y carrying sperm cells.
I remember reading an article a few years back that it is possible to select Y-chromosomes carrying sperm cells, has the X cells are slightly bigger. So, hopefully it was just a matter of having someone, over a microscope, doing a pre-selection.
As a side-note anecdote: men that board radar ships have a sharp decline of Y carrying sperm cells.
Not just ships, jet fighters (which have aggressive, powerful radars) and other roles with high radar exposure.
There is a meme: fighter pilots only have daughters.