Kind: captions
Language: en
okay go to the window or better yet step
outside a squirrel darts past trees and
weeds surge up towards the sky Birds
tickle the air get down on the ground
and there's more worms wriggling
mushrooms sprouting beetles crawling
there's stuff you can't even see like
bacteria and everywhere you go on this
planet on land underground in the air
and in the water there's more life to be
found and all of it even you is shaped
by the most incredible of forces
Evolution Evolution essentially
multiplies Majesty by Majesty by majesty
and our understanding of all that
Majesty it goes back to the mid 1800s
when an English 20s something a guy
named Charles Darwin got an invitation
he couldn't refuse to travel around the
world it was 5 years and that Voyage
made him into a thinker he was just a
great naturalist he saw things on in
nature and he asked why why as in why is
there such a stunning diversity of Life
why are similarl looking species
sometimes located on opposite sides of
the planet it was Darwin and Alfred
Russell Wallace who independently
puzzled out a mechanism behind Evolution
which was natural
selection natural selection just means
that nature the natural environment is
what selecting which organisms survive
long enough to reproduce and it depends
on two key ingredients the first is some
way of getting features or traits to be
inherited from one generation to the
next which usually means reproduction
the second is variation if organisms
were to make exact duplicates of
themselves every time they reproduced
nothing would change there'd be no
elephants no pine trees no humans we'd
still just be single celled Proto
organisms now the environment can
support every individual that's born
maybe it's too dry or too wet for some
of them maybe all the foods up in tall
trees maybe there's not enough food or
maybe it's just really cold whatever it
is organisms compete for resources and
this is where selection comes in for
instance scientists believe that a few
hundred, years ago before there were
polar bears some brown bears got
stranded in the Arctic the few that
survived likely had fur coats that were
a bit thicker and lighter in color than
the others that would have kept them
warmer and helped them blend in with the
snow to sneak up on prey more easily the
point is not all variations make it and
the things that survive go on to
reproduce in other words survival of the
fittest which doesn't necessarily mean
the biggest or the strongest fittest in
an evolutionary sense is Whoever has the
most descendants in the Arctic the Bears
with thicker and whiter coats survived
more often and had more offspring
offspring that inherited the thicker and
whiter fur and gradually other changes
accumulated too until this population
became a separate species from the brown
bears however if we were to swap out the
snow for a forest having polar bear-like
fur would likely be a bad thing in other
words Evolution doesn't progress in one
fixed Direction but it's not entirely
random either with so many environments
selecting for all kinds of traits
Evolution has resulted in the countless
species that have lived on
earth now Darwin wrote these ideas down
he was not a visual man so when he did
bother to draw something people took
notice like this image he sketched in
one of his notebooks it's a tree and it
tells us how things are related that is
they all can be traced back to a common
ancestor that ancestor the first living
organism on our planet is at the base of
the tree trunk here's another view of
this so-called phog genetic tree as
life's evolved over the last 3.8 billion
years new species have branched off
leading to entire lineages of different
organisms every branching point in that
tree is a story stories of global
domination of Extinction stories of
beauty and of remarkable adaptation to
an everchanging world I mean the goal of
the tree of life is try to understand
how every species is related to each
other the breath of this that is amazing
and that's where you come in in Nova's
Evolution lab you'll be climbing around
the tree of life to build out portions
of that tree to see how Evolution really
works and understand why it matters to
you like did you eat a dinosaur last
night for dinner can you save someone
from a venomous snake bite or do you
have a neanderthal ancestor play this
lab build the tree of life which is your
family tree and discover just how
connected you are to everything that's
alive and everything that's ever lived