I wasn’t suggesting a change in the DNA, I was simply asking a question. My question was very specifically related to sperm responding differently to the whatever chemical were present in our spinal fluid shortly before ejaculation. In the conversation I was following they were discussing changes to the DNA, my question is more about more favorable conditions for already existing sperm. Which is a lot different question. I used to breed dogs and we had some control over how many males and females we could get by breeding them at different periods during estrus. The condition of the females womb or the ph would favor male or female sperm. That would indicate that not all sperm respond the same to things.