On the outside, it may seem like
we haven't changed much from our early ancestors.
But take a closer look and you'll discover that humans
are still evolving in some fascinating new ways.
The average person can hold their breath for 30 seconds.
But Bajau people in Southeast Asia
can hold it up to 12 minutes
which comes in handy when they free dive
over 230 feet for food.
Part of the reason is simply training and experience
since they spend over half their workday underwater.
But it turns out, the Bajau also have a genetic mutation
that makes their spleens 50% larger than average.
Our spleens are what filter
and store oxygen-rich red blood cells.
So, when the Bajau dive underwater,
their larger spleens contract, which boosts oxygen levels
in the blood by up to 10%,
allowing them more time to collect food.
It's a handy adaptation that probably came
from living on houseboats for the last 1,000 years.
About 35% of the world's population has the equivalent
of a genetic superpower.
They can digest milk as adults.
Not impressed?
Then consider this.
Humans are among the only mammals
on the planet with this ability.
Thanks to a genetic mutation that popped up in Europe
around 5,000 - 10,000 years ago.
Those with the mutation produce lactase
throughout their lives.
That's the enzyme that breaks down milk sugars
for easy digestion.
And for most of history,
humans stopped producing lactase after childhood.
But once those lucky few Europeans could drink milk
as adults, that suddenly meant extra nutrition
and ultimately healthier, longer lives
so that they could pass their superpower
on to future generations.
Today, roughly 95% of northern Europeans have the mutation.
The human body has an estimated 20,000 - 30,000 genes.
And while some mutations can change our spleens and diet,
others can protect us against deadly conditions, like AIDS.
Nearly 50% of women in parts of South Africa have HIV.
But researchers found that some show stronger resistance
to the virus,
taking longer to develop AIDS
or sometimes never getting it at all.
Turns out, these women also share a mutation in the gene
called HLA-B27 that the others lack.
Are we going to evolve our way to HIV immunity?
It's too early to say.
But one thing's clear.
Evolution's not done with us yet.