Replies to post #253787 on Kraig Biocraft Laboratories Inc (KBLB)

[EOT]

Thinking a google search makes one qualified to critique what Kraig is doing is pretty funny! We really appreciate your intellect GT! Great work bud!!

[DimesForShares]

An organism can be homozygous dominant or homozygous recessive. If you breed a homozygous dominant AA with a homozygous recessive aa you get a heterozygous offspring Aa. Obviously we were both talking about the same situation.

For the sake of argument, let’s consider sickle cell disease. People can have no copies of the recessive abnormal gene, one copy, or two. Let’s call these AA (normal), Aa (heterozygous), or aa (sickle-cell). People with the heterozygous Aa combination are less vulnerable to malaria than either homozygous type. This is known as balanced polymorphism.

If you have a homozygous population of normal people and breed them with a population of homozygous aa sickle-cell people, their children are guaranteed to be heterozygous Aa and exhibit balanced polymorphism. When these children breed, their offspring will be 1/4 normal, 50% heterozygous, and 1/4 sickle cell homozygous. Only half will exhibit balanced polymorphism.

It doesn’t matter if the genes for, say, spider silk and large cocoons are dominant or recessive. Whichever the case, it is possible to breed a population that is homozygous for the desired traits and therefore breeds true. One does not need to maintain two breeding populations.

However, if the ideal combination is a heterozygous population exploiting balanced polymorphism, the best way to ensure a crop of only heterozygous eggs is to maintain two homozygous populations and cross-breed for one generation of production.

This discussion assumes the desired traits are governed by a single gene. That is seldom the case. My later discussion described the complexity of maintaining a population where balanced polymorphism is needed on multiple genes.

Obviously we don’t understand all of the issues. I was describing one possibility where the first generation offspring were fertile but the second generation was unlikely to exhibit the same desired characteristics, as suggested by the PR.

Nowhere does KBLB suggest the second generation is infertile. In both the situation I describe and your infertility example, it is much harder to steal cocoons from the production farm and breed similar cocoons, providing a measure of protection from intellectual property theft.