Average breast size differs a lot between European and Asian women. Within each population there’s also some spread.
If I wanted to understand the evolution of human breasts I would look more on how they differ in humans, what kind of genes are responsible for that and how the selection might work to get the differences between human populations.
Is it coincidence that Europeans are more adept to drinking cow milk and have larger breasts then Asian women?
Mongolians have almost the lowest tolerance for milk among human populations, and the absolute highest rate of dairy in the diet. They developed cooking techniques that overcome the intolerance to achieve this feat.
Another confounder in this area is much more modern: most claimed incidences of “lactose intolerance” are actually intolerance of protein changes from the machine homogenization process and flash pasteurizing process
The key research was on people who can drink goat milk which has higher lactose levels than cow, and people who can drink raw milk.
Not saying the consumption of milk in Europe is a coincidence, just saying seek larger amounts of evidence than you might initially expect to need. This area has a lot of noise hiding the signal.
When I asked ChatGPT, as far as it can tell we don’t have straight evidence that the EDAR gene affects breast size.
Even if it does have an effect, one interesting question would be whether there are multiple genes that result in the difference or one gene. If it’s multiple genes that would suggest that there’s a difference in evolutionary pressure on breast size, maybe because of cultural reasons or something else.
Within studied populations Eriksson et al. 2012 suggests that no single mutations carries the majority of the effect and breast size differences spread over many different genes.
Yes, the Eriksson study was one of ones supporting an early draft of this analysis. I didn’t end up using it because it didn’t make much sense to do so. Size isn’t the issue here; permanence is.
Erikkson only looks at Europeans, so I don’t know about the cross-population comparison here.
EDAR polymorphism does work through plausible pathways to produce the size difference and has other drastic phenotypic effects, but yeah nothing’s proven.
I don’t think this post is clear enough about knowing what’s going on that saying size isn’t the issue makes sense. When a phenomenon is unclear it’s hard to see what the central issue is.
One interesting aspect is that breastfeeding human mothers are infertile while they breastfeed. Yet continuing to have sex with the father is good for pairbonding and the father investing in supporting the mother in childcare.
Humans are fairly unique in that regard among primates and only Bonobos also have frequent sex during that period of fertility.
Moving from big breasts being a sign of infertility and thus not having sex in most primates to big breasts being seen as sexually desirable is an interesting change.
Average breast size differs a lot between European and Asian women. Within each population there’s also some spread.
If I wanted to understand the evolution of human breasts I would look more on how they differ in humans, what kind of genes are responsible for that and how the selection might work to get the differences between human populations.
Is it coincidence that Europeans are more adept to drinking cow milk and have larger breasts then Asian women?
Mongolians have almost the lowest tolerance for milk among human populations, and the absolute highest rate of dairy in the diet. They developed cooking techniques that overcome the intolerance to achieve this feat.
Another confounder in this area is much more modern: most claimed incidences of “lactose intolerance” are actually intolerance of protein changes from the machine homogenization process and flash pasteurizing process
The key research was on people who can drink goat milk which has higher lactose levels than cow, and people who can drink raw milk.
Not saying the consumption of milk in Europe is a coincidence, just saying seek larger amounts of evidence than you might initially expect to need. This area has a lot of noise hiding the signal.
But how buxom are those Mongolians?
I have never seen any research on the topic. Might need more grant funding.
I think a lot of the European/(East?) Asian difference you’re referring to is because of polymorphism in the EDAR gene.
When I asked ChatGPT, as far as it can tell we don’t have straight evidence that the EDAR gene affects breast size.
Even if it does have an effect, one interesting question would be whether there are multiple genes that result in the difference or one gene. If it’s multiple genes that would suggest that there’s a difference in evolutionary pressure on breast size, maybe because of cultural reasons or something else.
Within studied populations Eriksson et al. 2012 suggests that no single mutations carries the majority of the effect and breast size differences spread over many different genes.
Yes, the Eriksson study was one of ones supporting an early draft of this analysis. I didn’t end up using it because it didn’t make much sense to do so. Size isn’t the issue here; permanence is.
Erikkson only looks at Europeans, so I don’t know about the cross-population comparison here.
EDAR polymorphism does work through plausible pathways to produce the size difference and has other drastic phenotypic effects, but yeah nothing’s proven.
I don’t think this post is clear enough about knowing what’s going on that saying size isn’t the issue makes sense. When a phenomenon is unclear it’s hard to see what the central issue is.
One interesting aspect is that breastfeeding human mothers are infertile while they breastfeed. Yet continuing to have sex with the father is good for pairbonding and the father investing in supporting the mother in childcare.
Humans are fairly unique in that regard among primates and only Bonobos also have frequent sex during that period of fertility.
Moving from big breasts being a sign of infertility and thus not having sex in most primates to big breasts being seen as sexually desirable is an interesting change.