Antagonistic Selection and Invading Armies

We don't naturally look like this
We don’t naturally look like this

Evolution is a fabulous principle, but it can only do so much. It has yet to give us titanium bones or x-ray vision, nor has it solved the problem of death. It even gives us creatures like praying mantises, who eat their mates.

Genetically speaking, men and women are actually quite similar, at least compared to, say, trees. There’s a great deal of overlap between male and female instincts–we both get hungry, we both fall in love, we both think the Ghostbusters remake was an abomination.

While evolution would like* to code for perfect men and perfect women, since we are the same species and ever male has a mom and every female has a dad, genetics ultimately can’t code for perfect men and perfect women. *yes I am anthropomorphizing

Remember, there are only two chromosomes which code for sexual development, the so called XX (female) and XY (male). Both men and women have at least one X, but no women have a Y.

It doesn’t work out that men are, like, expressing half female genes and half male genes, since the Y chromosome blocks the expression of some of the female genes. However, men still have those genes.

Sexual antagonism or “sexual conflict” occurs when a genetic trait that makes one sex better at reproducing makes the opposite sex worse at reproducing:

Interlocus sexual conflict is the interaction of a set of antagonistic alleles at one or more loci in males and females.[6] An example is conflict over mating rates. Males frequently have a higher optimal mating rate than females because in most animal species, they invest fewer resources in offspring than their female counterparts. Therefore, males have numerous adaptations to induce females to mate with them. Another well-documented example of inter-locus sexual conflict is the seminal fluid of Drosophila melanogaster, which up-regulates females’ egg-laying rate and reduces her desire to re-mate with another male (serving the male’s interests), but also shortens the female’s lifespan reducing her fitness.

From, A recent bottleneck of Y chromosome diversity coincides with a global change in culture
From: A recent bottleneck of Y chromosome diversity coincides with a global change in culture

In humans, for example, women benefit from being thin and short, while men benefit from being tall and bulky. But a short, thin woman is more likely to have a short, thin, son, which is not beneficial, and a tall, bulky man is likely to have a tall, bulky daughter–also not beneficial.

Whatever instincts we see in one gender, we likely see–in some form–in at least some members of the opposite gender. So If there is–as some folks around these parts allege–an instinct which makes women submissive to invading armies, then it likely affects some men, too.

For the few men who do survive an invasion, not protesting as your wife is gang raped might keep you alive to later reproduce, too

Hence the recent rise of cuckoldry fetishes.

Cats are Cuckoos

Cats win at Evolution,” (from Cave People and Stuff,) is a great article about the evolution of cats from primate-predator to primate-parasite.

A quote:

“The domestic cat – aka Felis catus or Felis silvestris catus – is the same size as a human infant.  Its mew sounds very similar to the cry of a newborn human baby.  It has a round face with big eyes, like a human infant.  The domestic cat has gone down the same evolutionary route as the cuckoo, only much further.  Its entire life-cycle involves imitating baby humans and being coddled, fed and protected as though it were a human infant.”

Fabulous post. Go read it all.