Model of how a gay gene could be propogated from generation to generation

Harvey Newstrom (
Thu, 2 Dec 1999 01:09:17 -0500

Evolution is so central to the transhumanist ideals. It frustrates me to repeatedly see people spouting misinformation about evolution. The latest example of this is the recent discussion about homosexuality on the Extropians list. I can't believe how many people assume that there can't be a gay gene because gays don't reproduce. They say, "If gays don't have children, the gene would not get passed on to the next generation." This is totally simply wrong.

For the record, I don't believe (or disbelieve) in a gay gene. I am merely trying to show how a gene, such as a gay gene, that causes nonreproducing individuals can still get propagated to future generations. Here is an example of how an imaginary recessive gay gene could be propagated from generation to generation, even though gays don't reproduce.

  1. Imagine a simple recessive gene that causes gayness. Each person has two of these genes, one from their mother, and one from their father. Each strand of DNA from each parent either carries the gay gene (represented as "G") or the non-gay gene (represented as "g"). Since the gene is recessive, a person must have two gay genes to be gay. If there is one or more straight genes the person is straight. The possible combinations of genes are:
    GG = straight individual
    gG = straight individual, carrying gay gene received from father
    Gg = straight individual, carrying gay gene received from mother
    gg = gay individual, carrying gay genes received from each parent

2. Imagine a reproducing couple, each of whom has one gay gene. They are both therefore straight.

3. They mate and randomly pass on one gene each: Gg x Gg =

One fourth of their children will be gay (GG) and will carry the gene. One fourth of their children will be straight (Gg) and will carry the gene.
One fourth of their children will be straight (gG) and will carry the gene.
One fourth of their children will be straight (gg) and will not carry the gene.

4. The straight carriers of the gay-gene can and do propagate every combination of gay/straight genes possible to the next generation.

5. The cycle can repeat indefinitely with the following groupings for each generation:

This is just a simplistic example. Statistical studies on identical twins has already shown that if there is a gay gene, it is much more complicated than the simple example given here. However, the point is that it is easy for a gene that causes (virtual) sterility to get propagated from generation to generation.

Transhumanists have to lose the common misperception that genes that hinder individual reproduction would be weeded out by evolution. If the gene can exist in a dormant state, it won't affect the individuals passing it on. The fact is,
most of the genetic propagation of recessive genes occurs from gene carriers who do *not* exhibit the recessive gene's traits. I know this seems counter-intuitive
to most armchair evolutionists, but that's how it works.

Harvey Newstrom <mailto://>
Author, Consultant, Engineer, Legal Hacker, Researcher, Scientist.