Human Evolution Over the Last 10,000 Years

I wrote this once. I still consider it one of my best pieces of writing. I took what I had learned from my biology classes and synthesized it together.

Read Logan Bolan's answer to People who believe the theory of evolution, why do you think humans haven't evolved within the past couple thousand years? Shouldn't we have kept evolving? on Quora

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People who believe the theory of evolution, why do you think humans haven't evolved within the past couple thousand years? Shouldn't we have kept evolving?

We have. It’s just not as noticeable.

Have you ever tried to put your middle or ring finger to your thumbs? Watch the tendons in your forearm as the two tendons in the middle show up. Some people don’t have that because their ancestral reference populations had less need for extra tendons to help throw spears. It evolved out of the population. Others, not so much.

Some people have stronger, faster-swimming sperm. This is theorized to be due to the increase in cities nearly five thousand years ago. Females could now mate with multiple male partners. The men whose sperm could swim faster would reproduce more. Natural selection is in its most basic form, is mathematically measured by how much offspring in a population have a particular genotype and phenotype. The best genes spread out, so long as that population doesn’t have a major cause of genetic drift such as war, natural disaster, or famine.

Have you ever wondered why schizophrenia runs in families? Again, like most of this stuff, genes do two or three functions, depending on how the protein products are edited post-production, if you will. The genes associated with schizophrenia are associated with increased immunity. They produce protein products, that somehow, we don't know how yet, interfere with the development of the brain. Hallucinations may not be advantageous---but increased immunity in a time before vaccines absolutely is. (The creativity also is helpful too, just not in too big of a dose, otherwise, you get the hallucinations).

According to one paper in evolutionary medicine, people age faster because of particular traits that make them reproduce faster. Think about, just as an anecdotal frame of reference, how some people reach their peak faster. They grow more muscle, they’re more athletic, they get more attention from the opposite sex—-but that ability to grow muscle means they have more fat reserves, which when they stop working out, or keep eating the same amount as they did when they were teenagers, they get fat and become obese, diabetic—-they age faster than those who didn’t peak as soon. They have more offspring and thus that genotype will always be around.

In short, there is plenty of evolution going on—-it’s just not noticed, or you never thought of how something so crazy as schizophrenia could be beneficial to someone. The field you need to look at is evolutionary medicine and evolutionary psychology. That’s where a lot of the theories and evidence to prove those theories are being published. (And no, you don’t have to be an all-out atheist to be a scientist in those fields). The big changes haven’t been noticed such as changing from monkeys to humans, except for this one in Indonesia with the Sea Gypsies. Those take thousands of years of isolation to take place.

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