eli5: are dominant or recessive alleles more common in a population??

Question

i don’t understand . i thought there is no way to determine which is more common

In: 0

Answer 1

Dominant and recessive have nothing to do with how common an allele is. What they mean is that if you get a dominant allele from one parent and a recessive allele from the other, then you will show the dominant trait. But it’s possible that only 1 in a million alleles are dominant, so the trait will be rare.

You can use statistics to estimate how common an allele is in a population. Let’s say that for some trait, the recessive allele is 60% and the dominant trait is 40%. For a person to show the recessive trait, they need two recessive alleles. Since the recessive allele is 60%, you would expect that the trait will show up in 36% of people(60% * 60%). If you know how common a trait is in a population and you know whether it’s recessive or dominant, you can work backwards and figure out how common the allele is.