The additional uptake of sperm is only 5%. This might make a difference, but it might not be much. I’m guessing that the sperm in the first wave have the best chances, and adding a little more sperm at the back isn’t going to do much.
Some more guesses: If it’s true that 25% of women are reliably orgasmic, 50% are occasionally orgasmic, and 25% aren’t orgasmic, this suggests a single gene, but that would be surprising.
However, it also suggests a mixed strategy. Maybe non-orgasmic women are less inclined to adultery, so their marriages are less likely to get disrupted.
Maybe orgasmic women expect more, so that marriages that satisfy them sexually are better, but marriages that don’t are worse.
Maybe occasionally orgasmic and non-orgasmic women are less fond of sex, and therefore better able to bargain for family resources—which may include resources for their children.
Maybe occasionally orgasmic women try harder to get and keep mates, and keep those mates happy—intermittent reinforcement.
The additional uptake of sperm is only 5%. This might make a difference, but it might not be much. I’m guessing that the sperm in the first wave have the best chances, and adding a little more sperm at the back isn’t going to do much.
It’s not about the sperm with the best chances to fertilize, it’s the sperm with the best offensive and defensive capabilities, relative to another man’s sperm. Most spermatozoa are not even capable of fertilizing an egg; they are specialized “blocker” and “killer” units whose main job is to prevent other men’s sperm from reaching the egg.
That extra 5% isn’t about making a difference to whether she’s fertile, but about her ability to choose which man ends up as the father, out of the various men she’s having sex with.
Let’s say she has sex with two men, one right after the other—the one that makes her orgasm has a 5% larger army in the trenches, so to speak, which could easily be decisive.
(The book “Sperm Wars” discusses these and other evolutionary pressures on the orgasms, preferences, and genitalia of both sexes, in quite a bit more graphic detail than I think is appropriate for quoting here.)
If it’s true that 25% of women are reliably orgasmic, 50% are occasionally orgasmic, and 25% aren’t orgasmic, this suggests a single gene, but that would be surprising.
I think those figures are from Elizabeth Lloyd. They appear to represent figures for penis-caused orgasms.
“In fact, the majority of women reach orgasm through methods other than PVI, usually by direct clitoral stimulation”
25-50-25 doesn’t suggest a single gene very strongly. A gene can have any frequency—while practically any combination of genes could easily generate a bell-shaped curve.
The additional uptake of sperm is only 5%. This might make a difference, but it might not be much. I’m guessing that the sperm in the first wave have the best chances, and adding a little more sperm at the back isn’t going to do much.
Some more guesses: If it’s true that 25% of women are reliably orgasmic, 50% are occasionally orgasmic, and 25% aren’t orgasmic, this suggests a single gene, but that would be surprising.
However, it also suggests a mixed strategy. Maybe non-orgasmic women are less inclined to adultery, so their marriages are less likely to get disrupted.
Maybe orgasmic women expect more, so that marriages that satisfy them sexually are better, but marriages that don’t are worse.
Maybe occasionally orgasmic and non-orgasmic women are less fond of sex, and therefore better able to bargain for family resources—which may include resources for their children.
Maybe occasionally orgasmic women try harder to get and keep mates, and keep those mates happy—intermittent reinforcement.
It’s not about the sperm with the best chances to fertilize, it’s the sperm with the best offensive and defensive capabilities, relative to another man’s sperm. Most spermatozoa are not even capable of fertilizing an egg; they are specialized “blocker” and “killer” units whose main job is to prevent other men’s sperm from reaching the egg.
That extra 5% isn’t about making a difference to whether she’s fertile, but about her ability to choose which man ends up as the father, out of the various men she’s having sex with.
Let’s say she has sex with two men, one right after the other—the one that makes her orgasm has a 5% larger army in the trenches, so to speak, which could easily be decisive.
(The book “Sperm Wars” discusses these and other evolutionary pressures on the orgasms, preferences, and genitalia of both sexes, in quite a bit more graphic detail than I think is appropriate for quoting here.)
I think those figures are from Elizabeth Lloyd. They appear to represent figures for penis-caused orgasms.
“In fact, the majority of women reach orgasm through methods other than PVI, usually by direct clitoral stimulation”
http://findarticles.com/p/articles/mi_m2372/is_1_44/ai_n27219096/
25-50-25 doesn’t suggest a single gene very strongly. A gene can have any frequency—while practically any combination of genes could easily generate a bell-shaped curve.