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Adaptation leads to
Evolution
Ryan Kiddey
The Evolution Basics…
 What is a species?
 Species: a group of organisms that share very similar
traits and can reproduce only within that group.
 Traits are inherited from one generation to the
next.
 What is evolution?
 Evolution: Changes in inherited traits over time.
 What causes evolution?
 Natural genetic variations (mutations) in the genes
(DNA) cause evolution to occur over time.
Evolution? Who’s big idea
was it?
 Charles Darwin (1809-1882)
 An English guy
 In 1831, he sailed to the Galapagos Islands
on the HMS Beagle as a naturalist.
 Made very important observations while on
the islands.
 Darwin coined the term: Natural Selection
Darwin’s Finches…
Natural Selection…
 What is natural selection?
 Natural Selection: organisms with traits
best suited to their environment are more
likely to survive… Why???
 REPRODUCE!!!!!!!!!!!! THUS passing on
their best suited traits… most adaptable to
the environment.
 Mantis Video
The Principles of Natural
Selection
1. Organisms produce more offspring than can
survive.
2. Natural differences, or variations, occur
among individuals of a species.
3. Some variations are passed to offspring.
4. Some variations are helpful to the specie
within its habitat.
5. Over time, the offspring of individuals with
helpful variations make up more of the
population.

Eventually will become a separate species.
Variation and Adaptation
 Natural Selection accounted for differences among
species of finches AKA – Variation
 Variation: inherited trait that makes an
individual slightly different from other members
of its species.
 Caused by natural mutations in the genes/DNA
of the organism.
 What differences among us are caused by
variation?
 A good variation for some humans? FIV in Cats
and HIV in Humans
Variation and Adaptation
 Some variations are more helpful than
others.
 Variation can lead to adaptation
 Adaptation: any variation that makes an
organism better suited to its environment.
 What variations might a polar bear
require in order to adapt to a warming
world in order to survive?
Speed of Evolution
 The speed of evolution depends on the species
environmental conditions.
 Gradualism: a model that describes evolution as a slow,
ongoing process by which one species changes to a new
species --- tens of millions of years
 Punctuated Equilibrium:
 Model of rapid evolution which is caused by the mutation
of a few genes and results in a new species over a
relatively short period of time --- hundred thousand years
or a million years.
 gradualism vs. punctuated equilibrium (VIDEO)
Salamander Questions:
 1. What was the ecological cause of the salamanders
evolution?
 2. How do scientists know that the two species are
different at the other end of the valley?
 3. What things in their environment may have caused
these animals to adapt to become a new species?
Animals Adapt… How?
 Ring Species
 Question 1:
 The valley that separated the two…
 Why is this important?
 Question 2:
 They are different species because they
can no longer interbreed because their
DNA is so different.
 Question 3: What do you think…?
Why is adaptation and
evolution important?
 The Theory of Evolution is crucial to
biological sciences. Is a major reason
for the recent rapid advancement in
medicine and biological sciences.
 Human health… Any ideas why?
Evolution and Human
Health?
 New TB