Hey, Vsauce. Michael here.
A human, running like a quadruped, is creepy.
Artist Rui Martins created this animation
about a year ago. 127 years ago
Eadweard Muybridge shot these real images of a child with infantile paralysis
walking on all fours. Walking upright
looks less unnatural, our bodies are particularly well suited for it. It's one
of the things
the bulbous and prominent
human bottom helps us do. But let's get to the bottom
of a linguistic mystery. Why is the bottom
called a bottom, when it's in the middle of the body?
Your feet and legs are almost always
at the same level or below your bottom. I mean, except for
Navasana, the yoga boat pose, your bottom is
anything but the actual bottom of your body.
Unfortunately, there is no clear-cut
answer, but there are butt loads of cool things to learn
about butts. A buttload is not just a joke amount. It is a very specific
unit of measurement. Historically, it was used to describe the capacity
of a wine cask. A butt is about
477 litres, which means,
given the average volume of solid waste
the rectum holds, when a person says they have a
buttload of something... Technically,
they are saying they have enough of that thing to fill
3,200 butts. Using the word
bottom to refer to your posterior is relatively new.
Cedric Watts has presented evidence that in the late 16th century bottom could
connote the human rear end,
but the first published use wasn't until 1794
in Erasmus Darwin's 'Zoonomia'.
The word bottom comes from words meaning
'foundation', 'the lowest level'. But when standing or sitting,
the soles of your feet are more properly
at the bottom, and, sure enough, sole also means
'foundation', 'bottom'. What's going on here is probably a combination
of torso-centric thinking and euphemism.
Bottom is a nice word for a sometimes
dirty part and your bottom is the bottom of your digestive tract and
the bottom of your torso, the bottom of your body,
if you exclude your limbs. For Prince Randian,
a man born in 1871 in British Guiana,
the bottom was the bottom.
Because of tetra-amelia syndrome, he was born with no
limbs at all. In 1889 P.T. Barnum brought him to the United States to perform
in carnivals. And you can see him light a cigarette with no arms
or feet in the 1932 film
"Freaks". Bottom is just one of many words we have for the posterior,
the rear, the backside, derrière, bum,
buns or, in reference to its round shape, moon.
Which is why exposing your bare buttocks
is known as mooning, an offensive gesture.
The earliest known instance of mooning was recorded by Flavius Josephus. It occurred
in 66 A.D.
A Roman soldier mooned
a group of Jews headed to a temple in Jerusalem.
His act of mooning spawned a riot and the subsequent
overreaction on the part of the Roman military led to the
deaths of thousands of people.
If you get mooned you will,
just like a guy who died September 14th, 1865 and is now buried in West Laurens, New York,
Seymour Butts. At least he didn't share his name with a former
representative of New Hampshire's
second district. The word 'bum'
predates the use of the word bottom for the rear by quite
a lot. It's believed that the word bum originated as an onomatopoeia for the
sound of
buttocks slapping against a flat surface.
Seriously. Lazily sitting around on your
bum all day gave American English the word
bum, a loafer, an idle person.
And bum's connotation of uselessness, poor quality
caused it to lend itself in the late 1960s to the word
'bummer', an experience that was worthless -
a letdown. But to be clear, your butt
is a bottom, kind of. It's a bum
but it is not a bummer. Your butt is magnificent, an example
of what makes the human body so different.
Its shape comes from the gluteus maximus and gluteus medius muscles as
well as a layer
of fat. That layer of fat makes the bottom a great cushion
for sitting. Other animals have to sit
by resting weight on their legs because they lack the nice
bulbous butt of the human. Evolutionary psychology suggests that our attraction to full
firm bottoms on potential mates was probably
naturally selected. People in the past who liked
big ol' bottoms probably spread their genes quite
well. They probably had a lot of reproductive success because the calle
pigeon bottom
is a sign of health and youth. A bottom full of shapely fat
is a great energy reserve. That energy can come in quite handy if
food suddenly become scarce or during pregnancy
or breast feeding. There's a great reddit thread you can read if you'd like this
evolutionary psychology approach wrapped up in a
Sir Mix-a-Lot's "I like big butts" package.
Because we are bipedal in order to keep our torsos balanced while moving
we require relatively giant and prominent
muscles in our bottoms, muscles that are so prominent
we have, compared to other apes, very defined intergluteal clefts.
Butt cracks. This makes
certain hygienic practices more common in humans
than other animals. But those prominent muscles
are worth it. Compared to horses and other quadrupeds
humans can reach impressive long-distance
aerobic endurance running speeds.
This is Katarina Johnson-Thompson, an Olympic athlete from Great Britain
and an excellent example of the fact that humans
are the running animal.
Hi Michael.
Hi Katarina. Take a look at this.
I'll make it brief, but above and beyond other animals, humans can:
sweat to efficiently dump body heat, we have short toes to provide more efficient
force over long periods of running, our short neck ligaments keep our head perfectly
stable when running,
our uniquely well-developed Achilles tendon converts elastic energy into
kinetic energy
very well and our tall narrow waists provide great counter rotation as our legs
swing backwards and forwards. I like how PZ Myers
sums it up: "Over long distances, the average
speed sustained by a horse is less than that of the human,
which means that a well-trained conditioned human being
can keep up with, or even outrun, a horse
if the race is sustained long enough."
For this reason endurance running is still practiced by a few people on Earth
as a form of hunting and it may have been vitally important to prehistoric people.
Before domesticated animals and projectile weapons and traps,
humans caught animals for food in an incredibly
athletic way. David Attenborough documented this practice fantastically.
You should
definitely watch this clip. An animal will sprint away from running human
hunters but eventually
have to rest. Humans, on the other hand, though slow in the short run
can keep going. Like the tortoise, they eventually beat
the hare and can walk right up to the exhausted and overheated
animal to kill it. We don't have
dangerous claws or massive teeth and we can pretty much
only outsprint vegetables.
But, in the long run, thanks to things like our impressive
butts, we have superior endurance
when it comes to running. It may be called a bottom
but it's at the top of the list of things that make the human body amazing.
This video was inspired by Sport Relief.
A great cause that uses sport to raise money for vulnerable people here in the
UK and abroad.
Check the description of this video to learn more and watch their interactive
video about how you
can help out and get involved. But wait a second,
if our bodies are so well developed for endurance running
how come we don't all run marathons?
How come we don't all enjoy running
or do a lot of it? Well, the thing is all of this running specialization was
naturally selected
because it helped our prehistoric ancestors survive.
Actually enjoying all of that running was not naturally selected, it was just a part of their
daily lives. But that doesn't mean that today you can't
get off your butt, use your butt and be proud of it.
The next time someone calls you a butthead say
"thanks, I always knew my head was a superlative object that set me apart from
the animal kingdom."
Katarina
And as always,
thanks for watching.