As a geneticist with a focus on human genetics and inheritance patterns, I can provide an explanation of the dominance and recessiveness in hair color genetics.

Hair color in humans is a polygenic trait, meaning it is influenced by multiple genes. The two main genes that determine hair color are the MC1R gene and the HERC2 gene. The MC1R gene is particularly important because it has several variants that can lead to different hair colors, including blonde and red.

In terms of dominance and recessiveness, the situation is a bit complex. Typically, black hair is considered the most dominant color, followed by brown. Blonde and red hair are considered less common and are often recessive traits. However, the dominance can vary depending on the specific combination of alleles an individual has inherited.

For example, to have red hair, a person must inherit two recessive alleles for red hair, one from each parent. This is because the allele for red hair is recessive to the alleles for other hair colors. Blonde hair can also be recessive, but it is influenced by a combination of genetic factors, and the inheritance pattern is not as straightforward as red hair.

It's important to note that environmental factors can also play a role in the final hair color expressed by an individual. For instance, the same genetic potential for hair color can result in different colors depending on the level of melanin produced and other factors.

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Red hair is not actually a recessive gene (like blonde is), but is rather an "incomplete dominant." In the world of genes, there are dominant genes, which take over any recessive gene (brown, black), recessive genes (blonde), which will be taken over by any dominant gene, or incomplete dominent genes (red).read more >>