First off, this question was inspired by the following Facebook post:
“So since 50,000 years human haven’t evolved into anything different … yet [scientists] believe in Darwin theory that man evolved from apes and that doesn’t add up.”
This faulty argument is full of logical fallacies. Before we explain why it’s not even a valid argument, let’s tackle the facts.
First, while 50,000 years is not a long time in evolutionary terms, we do observe significant evolutionary changes in humans over this period. For example, we’ve seen the evolution of various skin, hair, and eye colors, as well as facial features and different shaped ears. These adaptations are responses to different environmental pressures and genetic drift as humans spread across diverse climates and geographies. To deny what we are seeing in real-time is to deny reality.
Second, the 50,000-year mark is particularly significant for the evolution of the human brain’s raw cognitive abilities. By this point, our brains had largely settled at their current level of complexity and capability. This does not mean that evolution has stopped. Human brains may stay this way for millions of years, or they may evolve significantly over the next few millennia.
Finally, the original faulty argument is both an “argument from ignorance” and a “false equivalence.” An argument from ignorance is when someone concludes that because they personally find something difficult to understand or believe, it must not be true. It is also a false equivalence, where the skeptic equates the relatively short period of 50,000 years with the much longer timescales required for significant evolutionary changes.
For an exploration of how the evolution of vocabulary in animals, take the deep dive: The Evolution of Vocabulary in Ancient Humans.
2 thoughts on “If evolution is true, why haven’t humans evolved in 50,000 years?”
Facebook User: “If the rate of our evolution has slowed it is at least partly because we’ve learned to carry our ideal environment with us. We’ve even learned to take it with us in outer space.”
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Mike Prestwood: Interesting thought, and in some ways, we do see what you’re talking about. For example, advancements in medicine have introduced new variables into the evolutionary equation, keeping people alive who might not have survived in earlier times. However, I’d argue that we are still evolving at a rapid pace. While it’s true that the human races that evolved over the last 50,000 years are mixing, and the “normal” process of evolving into sub-species and then separate species was interrupted. Still, as a massive group, we are evolving quickly.
From Facebook:
My reply:
Are you referring to the idea of a DNA bottleneck and what happened to indigenous people? For example in the Americas during the 16th century? If so, remember that while tragic, most of that DNA is still in the population today and will likely keep mixing in over the next millennia. Also, remember isolated populations like the Sentinelese people which have been isolated for about 60,000 years and have yet to even start mixing in their DNA.