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 is *usually* more common, but not necessarily.

Brown eyes are a dominant allele, and indeed most humans on Earth have brown eyes, but in some northern European populations, blue eyes are the majority.

A dominant allele is especially likely to be rare if it causes health problems (or death). Achondroplasic dwarfism is caused by a dominant allele on a single gene. One copy causes the condition to be expressed, but two copies is almost always fatal.