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Here's a mechanism that is infinitely times more plausible than the lack of mechanism in any article published so far, which doesn't rely on hand-wavy inter-ute

Here's a mechanism that is infinitely times more plausible than the lack of mechanism in any article published so far, which doesn't rely on hand-wavy inter-uterus sperm manipulation: Mothers with multiple sons (as opposed to mixed gender or primarily female) will have a higher likelihood of having a dominant son, thus more grandchildren, due to one or more of the combination of: 1) competition among sons generates sons able to compete against the larger herd/pack, 2) multiple raffle tickets are better than one, 3) cooperative dominance among siblings (they all work to dominate the rest), 4) in some species, only dominant males are allowed to breed (or are allowed to breed more often), which means that a male will father offspring from multiple mothers, of which sons will tend to be dominant based on their father's genetics, which feeds back on #1, #2, and/or #3. I'm not saying that any of these are the cause, but they are reasonably plausible, and have an obvious behavioral mechanism that could easily result in the numbers that the research shows.

azakai 13y ago
Maybe I miss your point, but it seems those are arguments for having more sons? The finding is that the ratio is overall 50-50, so there are not more sons overall. But that the ratio changes over time and individuals, sometimes with more sons and sometimes with less, depending on which would be more effective for the particular time and individual (if the individual has genes that would benefit a female more than a male, then more female offspring, etc.).
- DrJosiah 13y ago
  I'm going to use human terms, because talking about multi-species offspring is messing with my pronouns. They took a multi-generational history of a collection of mammals. Then they look at how many 2nd generation children are produced when 1st generation tended to be mixed in gender, vs. predominantly males. From this data, they determined that on average, the when the 1st generation of children tended to be male, they had 2.7 times (on average) as many 2nd generation children than if they had been in a mixed-gender 1st generation. From my perspective, it seems as though the study looked at all of the outliers in the population, then used an unsubstantiated hypothesis from 30 years ago to fit the outlier data, despite the fact that if you look at the general population as a whole, those outliers are expected in the sample, and might be explainable when you look at herd/group behaviors. There are potentially many factors that can lead to more children in the 2nd generation for male-dominated 1st generation, of which I listed 4 possible factors that doesn't rely on the mother determining the sex of their offspring. Color me a skeptic, but I'll believe social behavior before uterine gender manipulation any day of the week - especially in animals that are known to be social.

azakai 13y ago

Maybe I miss your point, but it seems those are arguments for having more sons? The finding is that the ratio is overall 50-50, so there are not more sons overall. But that the ratio changes over time and individuals, sometimes with more sons and sometimes with less, depending on which would be more effective for the particular time and individual (if the individual has genes that would benefit a female more than a male, then more female offspring, etc.).

DrJosiah 13y ago
I'm going to use human terms, because talking about multi-species offspring is messing with my pronouns. They took a multi-generational history of a collection of mammals. Then they look at how many 2nd generation children are produced when 1st generation tended to be mixed in gender, vs. predominantly males. From this data, they determined that on average, the when the 1st generation of children tended to be male, they had 2.7 times (on average) as many 2nd generation children than if they had been in a mixed-gender 1st generation. From my perspective, it seems as though the study looked at all of the outliers in the population, then used an unsubstantiated hypothesis from 30 years ago to fit the outlier data, despite the fact that if you look at the general population as a whole, those outliers are expected in the sample, and might be explainable when you look at herd/group behaviors. There are potentially many factors that can lead to more children in the 2nd generation for male-dominated 1st generation, of which I listed 4 possible factors that doesn't rely on the mother determining the sex of their offspring. Color me a skeptic, but I'll believe social behavior before uterine gender manipulation any day of the week - especially in animals that are known to be social.