"They all look alike": Understanding the "other race effect"

[Drolefille]

Originally Posted by VandalSquirrel

If there are more O people (which is a fact), and they are having kids with people who are AO BO or OO, their offspring are more likely to be O and not A or B. Since AB is the smallest group and there are AA and BB people, it isn't as if A B and AB will disappear, but they will decrease as the O people breed and their O kids breed and on and on. I'm not saying it will be significant in our lifetime, this is a long term process.

O is already the majority blood type, statistically it is more likely for someone to be O and mate with someone who is O. Even though it is recessive the more people out there who are O will increase the amount of people who are O, over time. Factor in the people who are AO and BO and there is potential for a lot more O blood type.

I'm speaking in averaged terms, it varies within groups, but being conservative O is at 40% and it going to keep rising when you look at the birth rates of particular groups and if O is more common.

http://www.ncbi.nlm.nih.gov/bookshel...rt=ch2#ch2.1.4

Sorry, I guess I need a source that talks about the increase. I've been looking because I didn't want to put it all on you to explain to me, though you've been quite kind to. It just doesn't make sense to me and I can't find any secondary sources.

I get that O is from 40-50% but even taking AO/BO people is only going to produce another OO 25% of the time. Crossed with an OO it's only 50%. I'm just not making the numbers work for me.

In short, I get the basics of what you're saying but I am not seeing the increase part of it.

[VandalSquirrel]

Originally Posted by Drolefille

Sorry, I guess I need a source that talks about the increase. I've been looking because I didn't want to put it all on you to explain to me, though you've been quite kind to. It just doesn't make sense to me and I can't find any secondary sources.

I get that O is from 40-50% but even taking AO/BO people is only going to produce another OO 25% of the time. Crossed with an OO it's only 50%. I'm just not making the numbers work for me.

In short, I get the basics of what you're saying but I am not seeing the increase part of it.

I'd have to dig through my notes from those classes and frankly that's not my priority until winter break when I clean crap out. It comes down to a lot of math and looking at birth rates of those with type O blood and their offspring. Like I said it is a long term process, kind of like genetic drift but not really. There is a heavy influence of culture as well, since mobility is increased and the areas where O is closer to 100% people are moving out of and having lots of babies with other O people or passing on O through their non O mates.

If people weren't able to move around things would be explained by the Hardy Weinberg Principle and stay in balance over time, however culture is the changing factor.

[Drolefille]

Originally Posted by VandalSquirrel

I'd have to dig through my notes from those classes and frankly that's not my priority until winter break when I clean crap out. It comes down to a lot of math and looking at birth rates of those with type O blood and their offspring. Like I said it is a long term process, kind of like genetic drift but not really. There is a heavy influence of culture as well, since mobility is increased and the areas where O is closer to 100% people are moving out of and having lots of babies with other O people or passing on O through their non O mates.

If people weren't able to move around things would be explained by the Hardy Weinberg Principle and stay in balance over time, however culture is the changing factor.

Looking at wiki it seems like the cultures that are ~100% OO appear to be mostly central/south american natives - Incans, Maya, etc. I know it's only wiki but it suggests it is more of a matter of balancing selection and without adaptive effects of the OO genotype there's a chance that O would be gone altogether outside of such populations.

I understand that this is secondary (tertiary... last on your list) to your current things to work on I'm just struggling with the logic of it in the absence of numbers.