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Sperm Count Zero

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Re: Sperm Count Zero

#152

Earlier quoted context omitted.

For a gene to decay without selective pressure takes a very long time, especially when your population is not on the edge of starvation.

A selective pressure going away is as strong as a selective pressure appearing. Eg. 100 years ago, 20% of children would die as infants. Imagine all of those children died of a mutation which causes half the usual sperm count, together with a lack of resistance to polio/cholora. Now that polio/cholora don't exist, all those people survive, and within 3 generations, nearly everyone has at least a grandparent with that…

> Eg. 100 years ago, 20% of children would die as infants. Imagine all of those children died of a mutation which causes half the usual sperm count, together with a lack of resistance to polio/cholora

That wouldn't be a steady state. A gene that powerfully negative, with no upsides, would decrease in prevalence by a significant amount every generation.

> Now that polio/cholora don't exist, all those people survive, and within 3 generations, nearly everyone has at least a grandparent with that 'low sperm count' mutation.

Everyone has an ancestor with the gene. But they only have a 1/8, 1/16, 1/32 chance of inheriting it from that specific ancestor. Generation to generation, the percentage of people with the gene will be almost identical. Just like eye and hair color.

Re: Sperm Count Zero

#155
post #8

Earlier quoted context omitted.

> followed by the bit about men becoming less male. This is pretty obvious without any research (papers). The difference between my generation and our children is already staggering in this regard. Not sure if that's just change in culture or physiological though; maybe a bit of both?

> The difference between my generation and our children is already staggering in this regard. Not sure if that's just change in culture or physiological though; maybe a bit of both? Said every parent about their children's generation since the dawn of human civilization..[0], [1] 0. http://mentalfloss.com/article/52209/15-historical-complaint... 1. https://www.bartleby.com/73/195.html

Yeah , this is about a particular trait that is not in either of the linked articles though. You took what I said out of context which makes it a platitude.
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