Are humans evolving?

Human evolution has stalled.

Do you remember how evolution works? I’ve asked questions to test people’s understanding of evolution and have received some weird answers.

Common Misconceptions: Some believed that actions an organism does (like more exercising or eating healthy) transforms their genes and they then pass on these healthy genes to their offspring. Some believed in full determinism ie.  all traits pass down generations without any changes at all.

How it actually works: If I were to describe evolution in  simple steps, it is thus:

  1. A population of organisms have a lot of varying traits (such as eye color, bicep size etc.)
  2. Some traits make it super easy for them to survive and reproduce. Examples:
    1. Big biceps may allow a guy to bash up others and steal their limited supply of food.
    2. Green/Blue eyes may make it easier for them to attract a mate and reproduce.
  3. There are some undesirable traits that threaten survival for an individual. Because individuals with undesirable traits cannot survive and procreate, these traits disappear eventually, making the entire population better.
  4. New traits emerge by chance. If beneficial, they propagate throughout. If not, they are nipped in the bud and disappear quickly.

Applying this to humans: 

I tried to imagine how this process is shaping humans. There are two checkpoints that exert evolutionary pressure on a species.

  1. Survival
  2. Reproduction

Technology helps survival: Over the last few hundred years, science and technology has enabled wonders like mass food production, disease control, vaccinations etc. Short of very rare incurable genetic diseases, there is very little in terms of genetics that make or break survival for humans. Humans don’t have to compete for limited resources now. Being smarter, faster or stronger hardly makes a difference to your survival chances. It is usually environmental and cultural factors that affect survival more.

Culture helps Reproduction: Similarly, while in most species only a few dominant individuals get to reproduce, in humans almost every person ( fat, bald, scrawny, dumb whatever) gets to have kids due to the institution of marriage/pairbonding (most animals typically have harem like societies). Paradoxically, reproduction has ceased to be a top goal for humans completely and the most successful humans are actually having less kids!

To summarize, what this means is that genetically determined traits are hardly having any bearing on survival or reproduction of humans. Since they have become inconsequential for survival or for reproduction, we should not see any major changes in humans due to evolution over the next few thousand years.

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