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Name __________________________________________
Period ______
Natural Selection and Evidence of Evolution
Evolution is ___________________ in ______________________
characteristics over time. (Descent with modification)
Before the 1800’s, few thought much about evolution.
1. Most people thought the Earth was only ____________ years old
instead of _________ BILLION years old.
2. Few ___________________ to see similarities in species.
3. Many people accepted the ________________ story of creation.
In the 1800’s, scientists started to change people’s minds….
Lamarck- A ___________________ scientist who proposed that traits
developed during a parent’s lifetime would be _________________ on to
their kids.
Example: Giraffes stretch their neck to reach tall leaves, this results in a ____________
neck. This trait is then _________________ by the kids.
Lamarck didn’t realize not all things are passed onto the offspring. (muscles, plastics
surgery, etc.) Genetics wasn’t described until the 1860’s by_______________
Charles ___________________ - A _________________ scientist who studied nature
and noticed similarities among animals. He concluded that all living things must be
________________________ and somehow they __________________________ or
evolved over time due to natural selection.
Natural Selection- An organism with the best _______________ for their environment is
more likely to _________________________ and ___________________________.
“Survival of the _______________________”
How does Natural Selection Happen? (How do we get the “fittest” organism or the one
with the best traits for its environment?)
1. Lots of _____________________________. (example_____________________)
2. __________________________ or variations occur in those offspring.
3. Some variations are _____________________, this results in a better chance of
_____________________, reproduction, and passing on of those traits.
4. Over time, individuals with new variations may become a whole new
____________________. This is ____________________________.
Adaptations are _____________________ that can make an organism better suited for
its________________________. Adaptations can be _____________________ (on
their body) or _________________________.
Adaptations can help an organism…..
Attract a ______________________, warn _______________________,
_____________________ from predators (camouflage), or imitate a more dangerous
animal ( ________________________)
Geographic Isolation can allow some variations to ________________in a
species that might have otherwise stayed hidden.
Geographic Isolation Model
Speed of Evolution
Gradualism: A continuous series of
_____________________ and variations which, over time
will result in a new species.
Punctuated Equilibrium: Rapid evolution that occurs when
the mutation of a few ______________ results in the
appearance of a new species over a relatively short period of
time.