For onlookers wondering about the genetic disorder thing, it was discussed in Evolving to Extinction. The relevant part:
Segregation-distorters subvert the mechanisms that usually guarantee fairness of sexual reproduction. For example, there is a segregation-distorter on the male sex chromosome of some mice which causes only male children to be born, all carrying the segregation-distorter. Then these males impregnate females, who give birth to only male children, and so on. You might cry “This is cheating!” but that’s a human perspective; the reproductive fitness of this allele is extremely high, since it produces twice as many copies of itself in the succeeding generation as its nonmutant alternative. Even as females become rarer and rarer, males carrying this gene are no less likely to mate than any other male, and so the segregation-distorter remains twice as fit as its alternative allele.
It just occurred to me that such a situation can rectify itself without the need for genocide :-) If females can detect males carrying the segregation-distorter, they will avoid mating with such males, because having female children is a reproductive advantage in a population where males outnumber females. Or am I getting confused again?
There would also be strong selective pressure for any genes which can override the segregation-distorter, even if the females can’t recognize the males which carry it.
If mothers made a habit of snacking on (each other’s) litters of all sons, that would counteract the problem. That wouldn’t require being able to differentiate among adult males, just between male and female children.
If the species takes a long time to wean children and doesn’t reproduce until that process ends, this works better.
Mice, pigs, rabbits etc. (animals with large litters) already eat weak children fairly often, so this is somewhat plausible.
Rather than rely on females recognizing things about males, what about genes that capitalize on the difference between regular males and those with the disorder—sisters!
Females could more greatly than presently value aggression (this would only need a boost, the trait already exists), and a gene could make females intervene to break up their brothers’ fights. Young males with the disorder would tear each other to shreds or be too timid to reproduce, and males without the disorder would have sisters preventing them from killing each other.
There would also be strong selective pressure for any genes which can override the segregation-distorter, even if the females can’t recognize the males which carry it.
“Strong” for sure. Unfortunately for the species it would have to emerge fully functional in the time it takes for the species to evolve to extinction. Not so easy.
Now I wonder why Eliezer’s post calls the original problem unsolved. Surely such elementary solutions couldn’t have evaded the experts in the field? I’m guessing that I made a mistake somewhere...
Unfortunately, this will only work in a population with a weak segregation distorter. Remember, mutations that do a specific thing are rare, and detecting the presence of a specific allele that doesn’t have large-scale phenotypic effects is tough. By the time the segregation distorting allele is a large fraction of the population it is almost too late for the population.
For onlookers wondering about the genetic disorder thing, it was discussed in Evolving to Extinction. The relevant part:
It just occurred to me that such a situation can rectify itself without the need for genocide :-) If females can detect males carrying the segregation-distorter, they will avoid mating with such males, because having female children is a reproductive advantage in a population where males outnumber females. Or am I getting confused again?
It seems easier to evolve a preference for incest.
There would also be strong selective pressure for any genes which can override the segregation-distorter, even if the females can’t recognize the males which carry it.
A modest proposal:
If mothers made a habit of snacking on (each other’s) litters of all sons, that would counteract the problem. That wouldn’t require being able to differentiate among adult males, just between male and female children.
If the species takes a long time to wean children and doesn’t reproduce until that process ends, this works better.
Mice, pigs, rabbits etc. (animals with large litters) already eat weak children fairly often, so this is somewhat plausible.
I love lesswrong!
Rather than rely on females recognizing things about males, what about genes that capitalize on the difference between regular males and those with the disorder—sisters!
Females could more greatly than presently value aggression (this would only need a boost, the trait already exists), and a gene could make females intervene to break up their brothers’ fights. Young males with the disorder would tear each other to shreds or be too timid to reproduce, and males without the disorder would have sisters preventing them from killing each other.
“Strong” for sure. Unfortunately for the species it would have to emerge fully functional in the time it takes for the species to evolve to extinction. Not so easy.
Nice!
Now I wonder why Eliezer’s post calls the original problem unsolved. Surely such elementary solutions couldn’t have evaded the experts in the field? I’m guessing that I made a mistake somewhere...
Unfortunately, this will only work in a population with a weak segregation distorter. Remember, mutations that do a specific thing are rare, and detecting the presence of a specific allele that doesn’t have large-scale phenotypic effects is tough. By the time the segregation distorting allele is a large fraction of the population it is almost too late for the population.