but why males? probably to dump accumulating genetic load through reproductive skew.

but why males? probably to dump accumulating genetic load through reproductive skew.

That is not a purpose, but rather a result.

Another observation. Females keep deleterious mutations in circulation longer than males.

but why males? probably to dump accumulating genetic load through reproductive skew.

?

I don't think you need to invoke anything other than trivers's work on parental investment-- more investment by females-> females are choosier -> reproductive skew-> more variance in males. should be reversed in species where males are the choosy sex, then.

p-ter, but why are there males around in the first place? we could be hermaphrodites and optimize the # of wombs. another idea is that sex is a phylogenetic constraint for complex oragnisms...i think hamilton mooted at some point.

The greater variance in men is probably also partially explicable by the fact that we only have one X.

If the data that suggests that approximately 40% of males in the past managed to pass on their genes, while 80% of females did so is robust, there would seem to be some interesting corollaries.

For example, despite the enforcement of monogamy reducing female options, it seems unlikely that they would forgo choice in whose genes they were willing to carry in their uteruses. Perhaps the extent of misstated paternity is really 30% or higher.

It would also seem to bear on forced intercourse (there is another name for that), since males must clearly be risk takers.

p-ter, but why are there males around in the first place? we could be hermaphrodites and optimize the # of wombs.

Hermaphrodites may be vulnerable to invasion by cheaters that only act as males, if males invest less in the offspring.

(The strategies actually observed in hermaphrodite taxa are all over the place, sometimes individuals compete to be males, sometimes femaleness is preferred, sometimes there are mutual enforcement strategies to cut down cheating. That makes it hard to test this idea. But I think intensified sexual conflict may be one reason why all organisms aren't hermaphrodites.)

Hermaphrodites may be vulnerable to invasion by cheaters that only act as males, if males invest less in the offspring.

(The strategies actually observed in hermaphrodite taxa are all over the place, sometimes individuals compete to be males, sometimes femaleness is preferred, sometimes there are mutual enforcement strategies to cut down cheating. That makes it hard to test this idea. But I think intensified sexual conflict may be one reason why all organisms aren't hermaphrodites.)

Wouldn't the best strategy, theoretically speaking, be an organism that is both hermaphrodite and also capable of asexual cloning? you can act like a male, or act like a female...., or if you can't find a mate, self-fertilise/clone as a last resort?
eg. are some plants like this?

Perhaps there's a physiological constraint on this so few animals can do this?

If I remember correctly, in birds the situation is reversed: males have two sex chromosomes, females have only one. If you have to make one gender into a mechanism for eliminating harmful alleles, making it females seems ludicrously stupid, but birds are overall rather elegantly efficient creatures. Sure, evolution is sometimes dumb, but I don't think gene elimination can be a purpose here - a useful side-effect, perhaps.