[Music]
we explain the science of skin color
what causes human skin tones to vary
among different populations of people
well a chemical called melanin that's
produced in our bodies gives the skin
a darker color the more people produce
the darker their skin will be
melanin's purpose is to work as a
natural sunscreen to absorb the sun's uv
rays
with that in mind regional skin colors
developed
naturally as a response to different
climates when our ancestors migrated
across the globe
tropical climates provided more uv
exposure than other regions
however too much exposure is damaging
this means natives from regions like the
equator had darker skin
since their bodies produced more melanin
to protect against these harmful rays
on the other hand too little uv light is
also damaging
because uv light provides vitamin d
which is essential to build
our bones therefore natives from cooler
regions north and south of the equator
often had lighter skin as a result of
less uv exposure
since they produced less melanin to
block uv rays
this ensured they received the vitamin d
they needed
it's important to note that diet also
plays a role in the development of skin
tones
for example a high seafood diet provides
an alternate source of vitamin d
that's why native people from alaska and
canada remained
dark skinned in low uv areas
all in all the variation in our skin
tones
is only due to a little natural
sunscreen
though we may not look alike we are all
human and together we
share our world