[music]
When it comes to
swimming in sand,
you can’t be too skinny
or too smooth.
That’s the lesson that
scientists at Georgia Tech
and Harvard have
learned from watching
this shovel-nosed snake.
They had done earlier
studies of a lizard called
a sandfish.
And those studies suggested
that long and thin
was probably the best shape
for this kind of movement.
High-speed X-ray movies of
the snake proved them right.
But the reason is not
what you might think.
It’s not just that the
snake is streamlined.
It turns out that
the long, thin body
of a snake with
lots of vertebrae
makes it much
easier to achieve
the complicated twists and turns
that make this movement work.
But the theory predicted
that, for the snake’s movement
to work, its skin had to be
smoother than the lizard’s
to cut down on friction.
Tests proved that
prediction right, too.
So why didn’t the
sandfish evolve
to be longer and thinner?
Well, it has other
demands in life,
like running on
top of the sand.
But the shovel-nosed snake
spends more time
under the surface of the sand.
And that life has made it one
slick, slender specialist.
