2009-04-08, 02:22 PM
Many people who look like they have black hair actually have the "brown" gene, but a very very dark variant, especially if they are Caucasian. My dad has hair like that, and my mom has brown. I have blonde hair. My sister has brown. So both my parents are Bb (B = brown, b = blonde). We're obviously both our dad's daughters, since we look more like him than we do our mom. 
I also have a strange toe muscle thing that my dad has, where I can move my big toe completely independently, like a thumb.
There is one gene for basic hair color (brown black red blonde) and multiple genes that interplay in complex ways that determine the highlights, tint, and darkness.
At least, that's one thing I've heard.
Here's another scheme I've heard: There is no such thing as a "black" gene, and it's simply a very dark brown, always. The reason people believed it was recessive is that your hair can't be darker than either of your parents' (skin is similar, by the way), so a light brown + a dark brown will usually be in between.
I also have a strange toe muscle thing that my dad has, where I can move my big toe completely independently, like a thumb.There is one gene for basic hair color (brown black red blonde) and multiple genes that interplay in complex ways that determine the highlights, tint, and darkness.
At least, that's one thing I've heard.
Here's another scheme I've heard: There is no such thing as a "black" gene, and it's simply a very dark brown, always. The reason people believed it was recessive is that your hair can't be darker than either of your parents' (skin is similar, by the way), so a light brown + a dark brown will usually be in between.