I was going to do this yesterday, but something was up with my server or something because I kept getting Error 500 for unmodified Moveable Type pages. Weird.

I’d like to refer you to an earlier post about negative eugenics if you don’t know what this is relating to.

I’m taking AP Biology right now, so I’ve learned a little about evolution, population genetics, and speciation. Thus, I can state specifically how we are stopping human evolution.

The first point is that humans beings make up a large population. Over 6 billion people, and all are pretty well adapted to their environment, or rather, the environment has adapted to people. There aren’t a lot of natural hazards we have to worry about. When a population is large and well-adapted, the gene pool is rather stable.

My book gives five factors that can change the equilibrium in a gene pool: mutation, gene flow, genetic drift, selection, and nonrandom mating. Let’s go over each one individually.

Mutation can cause quick changes. However, I’d like to restate that humans make up a very large population. This means that one small mutation won’t have much effect on the overall population since it only affects one person.

Gene flow is defined as the movement of genes in and out of the gene pool due to migration. Okay, it’s pretty easy to go from one place to another, but altogether, we make up one big population. People are still connected. To be a separate population, they must be isolated. Populations are not isolated from each other.

Genetic drift is a random change in the gene pool. Chance has a larger effect on smaller populations. Anything due to chance with our 6 billion plus people will probably be lost.

Neither artificial nor natural selection is taking place in developed countries. Unless you count the Darwin awards… But people are generally not being selected against. Those with unfavorable traits are allowed to live. (What traits? That’s tomorrow’s post.)

Nonrandom mating involves mating which is not random. There’s a great deal of relationships out there between people of different genetic backgrounds.

Moreover, speciation most often occurs due to isolation from one another. Humans are not changing because of the lack of isolation. There are many different types of isolation. Geographic isolation is pretty much moot because of the different types of transportation we have invented, allowing us to travel anywhere in the world. Humans are not ecologically isolated because we all live in the same environments. Seasonal and mechanical isolation haven’t really been a factor in humans ever. Humans mate year-round and I doubt there are any problems with… ahem, things not fitting correctly. Behavioral isolation only occurs in the loosest sense of the word. Humans do not have a set premating ritual that can be tampered with to stop mating between certain populations. The only type of isolation that may be in effect is prevention of gamete fusion. However, those couples can rely on in vitro fertilization.

None of the above factors are in effect. Our allelic frequencies are not changing. We are not evolving.