Genes come in pairs. A gene pair is homozygous when the two genes are the same. A gene pair is heterozygous when the two genes are not the same. A heterozygous snake has at least one heterozygous gene pair.

A heterozygous gene pair could contain a normal gene and a mutant (abnormal) gene. Or it could contain two different mutant genes. Most heterozygous snakes have a gene pair containing a normal gene and a mutant gene.

A heterozygous gene pair could contain a normal gene and a recessive mutant gene. In this case, the snake looks normal. Example: a heterozygous albino ball python has a normal gene paired with an albino mutant gene. Such a snake looks normal; it does not show the effect of the mutant gene.

A heterozygous gene pair could contain a normal gene and a dominant (or codominant) mutant gene. In this case, the snake does not look normal. Example: a heterozygous pastel ball python has a normal gene paired with a pastel mutant gene. Such a snake does not look normal; it shows the effect of the mutant gene.

Your best bet is to learn genetics from a genetics text, like Schaum's Introduction to Genetics, by Elrod and Stansfield. Trying to learn from other herpers almost guarantees a lot of misinformation, such as the claim that all het snakes look normal.

Paul Hollander

[ Show Entire Thread ]