Hi, this is Kate from MinuteEarth.
Our early ancestors were tasty snacks for everything from carnivorous mammals to birds
of prey; luckily, they had developed a basic predator pattern recognition system that quickly
located general threats and gave the primates time to escape.
But when predatory snakes first came on the scene, that system totally failed.
That’s because snakes are essentially stick-look-alikes whose hundreds of rib muscles and huge ventral
scales help them move in a way that no other predator does, which kept them incognito and
helped them chow down on unsuspecting prey.
But eventually, some of these primates evolved what amounted to snake detectors – adaptations
like neurons devoted specifically to snake-spotting – that helped the protomonkeys quickly recognize
a wriggling stick as dangerous and get out of Dodge.
Eventually, some of those helpful snake-sensing adaptations got passed down all the way to
Tests that measure the electrical activity in our brains show that when we look at pictures
of snakes, we experience lots of activity right at the point when the brain is evaluating
threats – far more than when we’re looking at pictures of other predators.
And take a look at these sequences – you’ll probably see the creature on the top in an
earlier frame than you see the one below, because your brain needs less visual information
to pick out a snake than to identify other animals.
Some researchers even think that we evolved our awesome color vision, in part, to help
us successfully spot snakes.
And there’s some evidence that our sensitivity to snakes actually makes us prone to fearing
them, but we don’t yet know exactly how.
What is clear, though, is that we definitely have snakes on the brain.
Hi! This video was sponsored by 23andMe – it’s a personal genetic analysis company that was
created to help people understand their DNA and to offer insight into their ancestry,
their personal traits, and their health.
You science lovers will probably figure out the name right away – it’s a nod to the
23 pairs of chromosomes that carry each of our DNA.
So they actually sent me this test kit to learn about my DNA story — I’m pretty excited
to try it out – all I have to do is to spit into this tube; there’s no needles, no blood,
it’s really easy.
We’ll get the results back in a couple of weeks, and I’m actually going to share some
of them with you guys in one of our next videos!
Hopefully they can tell me where this red hair came from, because I have no idea.
To learn about your DNA story and to support our channel, go to 23andMe.com/MinuteEarth.
See you next time!