> This paper is arguing that in addition to sexual selection's first order directional effect, there's an overlaid second order effect on variability, and the argument makes sense. Male reproductive success is already highly variable, because male gametes are cheap. Some males end up being disproportionately successful, e.g., Genghis Khan. From a gene's point of view, being hosted in Khan was winning the jackpot.
The paper makes no distinction between sexes -- so a discussion of male or female differences, whether in reproductive success, does not discuss on the paper's model.
> If you have a number of male offspring, some of them will be evolutionary "duds" no matter what. If you increase the variability in reproductive success of your male children, then some of them will be less reproductively successful and others will be more successful. But there's an asymmetry: "duds" are already duds and can't be made less successful, but on the other side of the curve, by increasing variability, you increase the likelihood of a jackpot.
Your argument holds the selectivity of the female sex as constant, and discusses variability of the male sex.
The paper's argument is about variability in one sex ('sex B') being a function of the selectivity of sex A. These are fundamentally two different arguments, and so whether your argument is true or not, your argument does not discuss the paper's model.
> The effect doesn't apply to female children, since a female mammal cannot have 200 offspring in her lifetime, but a male mammal certainly can.
Addressed in a previous comment.
> (Your fruit analogy is inapt, since fruit in a bag don't reproduce among themselves and regress toward the population mean.)
Thank you - I did not know this until now. I assumed that fruit reproduced asexually in bags.
My fruit analogy is presented because the error that the paper seems to make happens at a simple statistical level -- because the paper assumes that you can 'sort' a two variably desirable populations (B1 and B2) on a histogram by desire, find the top 25% of the population (B11), and assume that the top 25% desirable population (B11) is as variable as the original population it came from (B1).
The paper makes no distinction between sexes -- so a discussion of male or female differences, whether in reproductive success, does not discuss on the paper's model.
> If you have a number of male offspring, some of them will be evolutionary "duds" no matter what. If you increase the variability in reproductive success of your male children, then some of them will be less reproductively successful and others will be more successful. But there's an asymmetry: "duds" are already duds and can't be made less successful, but on the other side of the curve, by increasing variability, you increase the likelihood of a jackpot.
Your argument holds the selectivity of the female sex as constant, and discusses variability of the male sex.
The paper's argument is about variability in one sex ('sex B') being a function of the selectivity of sex A. These are fundamentally two different arguments, and so whether your argument is true or not, your argument does not discuss the paper's model.
> The effect doesn't apply to female children, since a female mammal cannot have 200 offspring in her lifetime, but a male mammal certainly can.
Addressed in a previous comment.
> (Your fruit analogy is inapt, since fruit in a bag don't reproduce among themselves and regress toward the population mean.)
Thank you - I did not know this until now. I assumed that fruit reproduced asexually in bags.
My fruit analogy is presented because the error that the paper seems to make happens at a simple statistical level -- because the paper assumes that you can 'sort' a two variably desirable populations (B1 and B2) on a histogram by desire, find the top 25% of the population (B11), and assume that the top 25% desirable population (B11) is as variable as the original population it came from (B1).