Help understanding Het's

[rabernet]

ok thanks for the replies,

Now where do the %66 and %50 hets come from

With recessive genes, an animal needs to receive two copies to show the visual mutation.

Hets carry one copy of the gene. In your example, the Piebald is contributing one copy of the pied gene to the pairing, making all the animals be 100% Het Pied.

We'll stick with pieds for this example.

When you breed a Het Pied (1 copy of the pied gene, 1 copy of the normal gene) to a normal (or anything that's not also pied or het pied), the het pied will contribute EITHER a copy of the pied gene, or a copy of the normal gene.

The offspring will be classified as 50% POSSIBLE Het Pied - because each resulting snake had a 50% chance of inheriting the pied gene and a 50% chance of inheriting the normal gene. It can only be changed from the designation of 50% possible het pied once it proves out to indeed carry the gene through future breeding.

Now - when you breed 100% Het Pied to 100% Het Pied, let's say you get four eggs. Statistically, if the statistics played out perfectly - you'd get 1 pied (inherited a copy from both parents of the pied gene, giving it two copies to produce a visual), 1 normal (inherited 2 copies of the normal gene from both parents), and 2 het pieds (received a copy of the het pied gene from one of the parents, and a normal gene from the other).

So that's three visually normal animals. Since you can't tell without breeding, which inherited the gene, and 2 out of 3 (or 66% of the remaining clutch) could carry the gene, they are designated as 66% possible het pieds.