Ask Biologists 🙋👨‍🔬 🧬

Dominant and recessive genes aren't in some cage match to decide who will win. Basically everyone has two copies of every gene because we have two copies of all our chromosomes - one from each parent. "Dominant" and "recessive" are words that describe what happens when you happen to have two copies ("alleles") with slightly different effects, and the overall effect on the organism is the same as that of one of the alleles but not the other. When you have two alleles, A and a, with two different effects, and people with AA have effect 1 and people with aa have effect 2, and people with Aa have effect 1, then we say allele A is dominant over allele a - if you have both it's like you only had A.

But that's the effect on the organism. In terms of getting passed down to your own offspring, both alleles have the exact same odds of getting there: 50%. So being recessive doesn't get in the way of being passed down. In fact a lot of harmful alleles are recessive because it's the only way they can get passed down, if their effect doesn't always manifest and you need the bad luck of having two of them for it to happen. Being recessive also doesn't prevent a gene from having an effect, it's just that its effect will only be seen in individuals that happen to have two copies of it. That's less impactful than if the gene were dominant but it's not nothing.