- #1
James_Frogan
- 28
- 0
Hi everyone,
I'm studying physics and not biological sciences, but I've been wondering about recessive genes recently. Given my background, do be kind on the explanations. My question is: if a recessive gene tends to be overcome by the dominant gene, how do recessive traits still display today?
What I understand of genes: if there is a dominant gene in a pair, then the dominant gene trait will show (eg black hair in black-blonde combination). If 2 people with black hair have a child, it's possible to have a blond baby if they both have black-blonde genes.
From a mathematical viewpoint, the probability of black-black and blonde-blonde producing a black-blonde is 100%. The probability of a black-blonde and a black-black producing a black-blonde is 25% (and black-black 75%). And 2 black-blondes have 50% chance of black-blonde and 25% chance pure black or blonde.
If the early human population were mostly black haired, how did blonde haired people defy the probabilities and become numerous? They would mathematically start off and die shortly after, if I see my probabilities correctly. Obviously this is not the case, so what am I misunderstanding about genes?
Cheers for your responses :)
I'm studying physics and not biological sciences, but I've been wondering about recessive genes recently. Given my background, do be kind on the explanations. My question is: if a recessive gene tends to be overcome by the dominant gene, how do recessive traits still display today?
What I understand of genes: if there is a dominant gene in a pair, then the dominant gene trait will show (eg black hair in black-blonde combination). If 2 people with black hair have a child, it's possible to have a blond baby if they both have black-blonde genes.
From a mathematical viewpoint, the probability of black-black and blonde-blonde producing a black-blonde is 100%. The probability of a black-blonde and a black-black producing a black-blonde is 25% (and black-black 75%). And 2 black-blondes have 50% chance of black-blonde and 25% chance pure black or blonde.
If the early human population were mostly black haired, how did blonde haired people defy the probabilities and become numerous? They would mathematically start off and die shortly after, if I see my probabilities correctly. Obviously this is not the case, so what am I misunderstanding about genes?
Cheers for your responses :)