Speaker 1: Welcome to brain Stuff production of I Heart Radio. Hey
Speaker 1: brain Stuff. I'm Lauren vog Obam and this is a
Speaker 1: classic episode from our archives and from our prior host,
Speaker 1: Christian Sager. Today's topic may or may not have been
Speaker 1: inspired by his pervasive love of the X Men. Are
Speaker 1: humans still evolving? Welcome to brain Stuff. I hope you
Speaker 1: survived the experience. I'm Christian Sager, and I'm the best
Speaker 1: there is at what I do. And today I'm going
Speaker 1: to tell you how human beings are still evolving. But
Speaker 1: into what I mean, like, where are cool mutant powers
Speaker 1: that cause fear and hate in those were sworn to protect?
Speaker 1: Where's my organic steel skin or my optic I beams? Well,
Speaker 1: contrary to some professor's assertions, evolution does not leap forward.
Speaker 1: Most experts agree that to give rise to a new
Speaker 1: species like mutants, we needs some kind of geographic isolation
Speaker 1: from other humans. Otherwise, cross breeding makes it less likely
Speaker 1: that mutations will be established in our gene pool, and
Speaker 1: with a densely packed planet full of planes and cars,
Speaker 1: it's highly unlikely we're going to find that kind of seclusion.
Speaker 1: Think of it this way. Genetic mutations are only passed
Speaker 1: down if they afford us some kind of benefit through
Speaker 1: natural selection, that doesn't mean we've stopped evolving. In fact,
Speaker 1: over time, we've already developed powers well sort of like
Speaker 1: how about the power to drink milk or fight disease?
Speaker 1: Because these, along with tiny teeth and small brains, are
Speaker 1: the mutant powers most of us are born with. Let's
Speaker 1: start with the milk powers, otherwise known as lactase persistence. See.
Speaker 1: Milk contains a sugar called lactose, and people need an
Speaker 1: enzyme called lactase to digest it. Most manimals lose this
Speaker 1: enzyme after they stop breastfeeding, but certain human populations have
Speaker 1: evolved so their lactase persists, allowing the digestion of milk.
Speaker 1: This was nutritionally advantageous, especially when we domesticated cows and goats.
Speaker 1: Now this genetic mutation is carried by more than of
Speaker 1: people of Northern European descent. Researchers have also found signs
Speaker 1: of another set of human mutations that were devoted to
Speaker 1: fighting off infectious diseases. Afflictions like malaria or tuberculosis used
Speaker 1: to mean bang, you're dead, but over the last forty
Speaker 1: thousand years we evolve to be more resistant to disease
Speaker 1: because our ancestors happen to have the right genes to
Speaker 1: fight off these viruses and bacteria, our mutant power to
Speaker 1: resist disease may not last much longer. However, as we
Speaker 1: become more dependent on medications for survival, our immune systems
Speaker 1: will slowly weaken. The more that pathogens are defeated by drugs,
Speaker 1: the less our body will need the internal functions to
Speaker 1: withstand them. This is not to say that modern medicine
Speaker 1: or vaccinations are bad, because without them we'd see a
Speaker 1: huge increase in disease related death, which I'm going to
Speaker 1: assume you also think is a bad thing. So maybe
Speaker 1: milk powers or anti disease genes aren't what you were
Speaker 1: hoping for. What about smaller jaws and less teeth. Our
Speaker 1: ancestors had huge jaws so they could chew on tough
Speaker 1: foods like roots and nuts, and wisdom teeth helped them
Speaker 1: replace their worn down pearly whites from tearing meat apart
Speaker 1: with no quarter asked and none given. But today our
Speaker 1: food is softer, easier to chew, and we use utensils
Speaker 1: to cut the portions we put into our mouths. Consequently,
Speaker 1: our jaws got smaller, our teeth are half the size
Speaker 1: they used to be, and we don't really need wisdom
Speaker 1: teeth anymore. They're already gone in some ethnic groups, and
Speaker 1: many predict they'll disappear entirely. Now. I don't need telepathy
Speaker 1: to know that you think these are really lame powers.
Speaker 1: How about one more mutation. Did you know that our
Speaker 1: brains have been shrinking for the last thirty thousand years.
Speaker 1: Some researchers think this means we're getting dumber, because the
Speaker 1: safety of modern society doesn't require intelligence for survival, but
Speaker 1: others argue that smaller brains just mean they're more efficient.
Speaker 1: Maybe our wiring up there takes up less room because
Speaker 1: it's faster, like when you get a newer, smaller phone
Speaker 1: that has better RAM than your old one. Hopefully, as
Speaker 1: my brain reaches peak efficiency, I'll be able to focus
Speaker 1: the totality of my psyche into some kind of weapon.
Speaker 1: Today's episode was written by Christian and produced by Tyler Clang.
Speaker 1: Brain Stuff is a production of I Heart Radio's How
Speaker 1: Stuff Works. If you miss Christian and want to hear
Speaker 1: more about the X Men, check out his podcast about
Speaker 1: the culture of pop culture, super Context and For more
Speaker 1: on this and lots of other topics, visit our home
Speaker 1: planet hows toff works dot com plus for more. Podcast
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