Human Evolution: Things You Didn't Know About How We Evolved

By | February 4, 2021

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The size and shape of the skull changed over time. The leftmost, and largest, is a replica of a modern human skull. (Carolyn WIlczynski/Wikimedia Commons)

Most people know the basics of human evolution: We walk on two legs, we're not covered in coarse hair, and he have opposable thumbs we can use to change the channel and smack the space bar. But there are so many tiny evolutionary changes that have affected the human race (and still affect us today) that we don't really think about.

Men With More Testosterone Are No Longer The Best Mates

The convention wisdom of evolutionary psychology is that men with features that signal high testosterone levels are more attractive to women seeking a mate in the most literal sense because they're more likely to be better providers. That might have been true in the good old days, when "providing" mostly entailed throwing sharp sticks, but that appears to be changing. In 2013, a group of researchers came to the conclusion that testicular volume and high testosterone levels were in direct opposition to human fathers' parenting effort in the modern era. The study found that men with high testosterone were more likely to involve themselves in "precopulatory, intersexual competition" but less likely to take part in the day-to-day work of taking care of their children.

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Human mandible. (Dake/Wikimedia Commons)

Our Jaws Are Shrinking

Apparently, humans used to have huge jaws, but over the last 30,000 years, they've been shrinking. Part of the reason is shifts in dietary practices, especially toward processed or otherwise softer foods that don't require big, meaty jaws to chew, but also because our bodies in general have gotten smaller. That's why most people have to have their wisdom teeth removed: Once upon a time, there was plenty of space for them to grow in without issue, but now, they're usually forced to painfully crowd the rest of the teeth (which have also become smaller) if left untreated.