Explain "supers" to me plz

[kc261]

Alright, this explanation is also a question of clarity for myself.

So is a super like this? Supers come from co-dominant traits correct?
So you guys all remember learning about genetics in biology? Well I remember it with flowers.

Red flower is dominant, pink is co-dom, and white is recessive.

So if you breed two pink flowers together, you get a hot pink flower.

Is that basically how it works?

Um, not quite. First of all, I think it depends on the species of flower, so for all I know, that would be true for some species.

However, red/white/pink flowers are an example frequently used in biology text books to illustrate incomplete dominant traits. Red and white are incompletely dominant to each other, so if you breed them together, you get pink. If red and white were co-dominant, you'd get flowers with red and white spots instead of pink. If red was dominant and white was recessive, you'd get all red, which would be het for white, but you couldn't tell by looking at them. And if white was dominant to red, you'd get all white flowers which would be het for red, but you couldn't tell by looking at them. (These examples assume that the red dominant flower and the white dominant flower were homozygous, which isn't really a safe assumption unless they've been breeding true for several generations.)

To try to put it into BP terms, first of all forget about the difference between incomplete dominant and co-dominant. They work the same as far as breeding goes, so it doesn't matter that much. Most of the BP traits that are commonly referred to as co-dom are actually incomplete dominant traits if you wanted to be technical about it, but for the rest of this explanation I'm just going to use co-dom to keep it simple.

So, assume white is the "normal" or "wild" type. One day, someone sees a pink flower. They get all excited. Cool! New morph! They breed it to a white/normal flower. They get (approximately) 50% pink and 50% white offspring. At this point, the pink morph could be dominant, and the individual pink flower that was found was heterozygous, OR the pink morphs could be co-dom. You can't be sure at this point.

Eventually, they breed a pink to a pink. They get (approximately) 50% pink, 25% white, and 25% red. They got a super, yay! And that proves that the trait is co-dom.

So, yes, supers come from co-dom traits. Dominant and recessive traits are either "on" or "off", but co-dom traits have a "halfway on" possibility, and the "fully on" expression is called the super.