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Evolution
Origins of Life
Natural Selection
Survival of the Fittest
The Theory of
Evolution is the idea that life did not always look
and act as it does today. People were not always
walking the planet since day one. In fact, much
evidence would suggest that there were hundred
of millions of years that showed many different
species walking, swimming, and flying over the
Earth, none of which were human.
Over time, species will change, or adapt, to the
environment that surrounds them. If they do not,
they will perish, and could possibly become
extinct, as many species already have.
Darwin
First scientists to propose the idea of
evolution
Travelled to the Galapagos Islands to
study local wildlife – finches
Made the connection between the
beak structure and their diet
Survival of the Fittest
The organism with the best adaptations
will survive
Adaptation – a trait/characteristic an
organism has that helps them to survive
Natural selection – the theory that
nature “chooses” the strongest
organisms to pass on their traits
Adaptations
Adaptations are what make organisms
unique
Examples include camouflage, defensive
mechanisms (crab claws, skunk spray, or
porcupine needles), poison/venom, even
mimicry (looking like other animals)
Failure to adapt to one’s environment will
result in extinction.
Whale Evolution
UC Berkeley
Selective Breeding
When humans hand pick which
animals can breed and which ones
can’t, it is called selective breeding
Those traits that we wish to be passed
on to the next generation are. Animals
with undesirable traits are not bred,
therefore their traits are not passed
down.
Examples: Dogs (wolves), horses, cats
Where did all the dinosaurs go? 
No one is sure. All we have left are the
fossilized remains.
Many species who once lived on the planet
are now considered to be extinct.
Extinct – Any species who once lived on Earth
but has since died out – no living members of
the species remain.
Ancestry
Since we evolved from other life forms, other
species, it stands to reason that we are
related to other organisms that look nothing
like us.
Generally, life started off as simple, singlecelled organisms and grew into complex,
multi-cellular life capable of performing a
variety of different functions. This variation
among different species was the result of
chance mutations that ultimately caused
one organism to survive or adapt better than
other organisms.
Phylogeny
In order to help
classify and
connect different
species, scientists
create family trees
to show how closely
related different
organisms are and
whether or not they
share any common
ancestors.