Name: 人間が鋭い前歯を持つ本当の理由 (The Real Reason Humans Have Those Sharp Front Teeth)
Uploaded: 2021-01-14T08:17:38.000Z
Duration: 3 min 5 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

Narrator: Lions have them, hippos have them,

they're actually the longest teeth in the human mouth.

The real reason is actually much more romantic than that.

Human men today have 10% longer canines than women,

and this difference isn't unique to our species.

Males' canines are twice as long as females'.

males compete for exclusive mating rights to

Over time, gorillas have evolved increasingly longer canines,

Our canines have actually become shorter over time.

Just look at the canines on the first human,

or Australopithecus anamensis versus modern humans.

In fact, our canines today are the shortest

who take after our shared ancient ancestors,

with their teeth somewhere along the way.

Now, scientists aren't entirely sure why this happened,

As a result, all that's left in our mouths today

to grab and hold on to prey the way lions use them,

predators' arrivals the way hippos use them.

Instead, they help us bite into food. That's it.

Turns out, evolution isn't always useful,

anthropologists use canine size and shape

to help track when humanlike ancestors evolved.

So in a way, our tiny canines make us who we are.

字幕リスト動画再生

人間が鋭い前歯を持つ本当の理由 (The Real Reason Humans Have Those Sharp Front Teeth)

entire

eventually

grab

ancient