Introduction to Evolution
Mr. Modafferi
Biology 9 - Regents
Do Now
How many recorded species are there in the
world?
1.4 Million Recorded
Interesting Fact
Hydrothermal vents along the floor provide a type of
chemical energy for bacteria. These bacteria use this
energy like plants use the energy of the sun. They then
form the base of a giant food web thousands of feet
below the surface. Only until recently have we been
able to discover this new habitat. Now scientists believe
there could be as many as a million species just in on
the ocean floor.
How is it possible that there are so
many different species?
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The Theory of Evolutionary
Evolution
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The genetic changes in organisms over time
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This explains how modern organisms have
descended from ancient organisms
Occurs in populations of organisms, not
individuals
Evolution is one of the great unifying theories of
biology
“Scientific” Theory
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Statements or models that have been tested
and confirmed many times
THERE IS NO DOUBT IN THEORIES
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Theory is almost as good as fact because it has
been tested and retested by many people.
Properties of Theories
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They explain a wide variety of data and
observations
They can be used to make predictions
They are not absolute, they serve as a model
of understanding the world and can be
changed as the world view changes
Question of the Day
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How did organisms change over time
(evolve)?
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How is a Giraffe’s neck longer now than it was in
the past?
Lamarck’s Hypothesis of Evolution
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Lamarck (1744-1829)
1)Believed that species would gain or lose
features if they overused or didn’t use them
- They adapted to their environment
2)Inheritance of acquired characteristics
- Lamarck believe that organisms become
adapted to their environment during their
lifetime and pass on these adaptations to their
offspring
Use and Disuse - Explained
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New structures arise because they are needed
Structures already present become better
developed due to frequent use
Structures that are not used decrease in size
and eventually disappear
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A giraffe stretched its neck to reach higher leaves, and this
stretched neck would be a trait inherited by its offspring
Lamarck’s Theory Was
Proven Wrong!
Think Logically
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If you had a terrible accident and one of your
limbs got amputated would your offspring not
have that limb when born?
Who is the “main man” of evolution?
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Charles Darwin
Born: February 12, 1809
The main contributor to the modern theory of
evolution
He wrote The Origin of Species in 1859
Charles Darwin
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Darwin made many observation and collected
different specimens during his five-year
journey on the Beagle.
Please take out your map of Darwin’s journey
and lets discuss some of his observations!
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Darwin's many observations led him to the
idea that species slowly change over time
Darwin's comparison of the animals of South
America and the Galapagos Islands caused
him to conclude that adaptation to the
environment can cause diversification,
including origin of new species
Examples: Patagonian hares replaced rabbits
in the South American grasslands
Please Take Out a
Piece of Paper
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Write Down:
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3 things you learned
2 things you found interesting
1 thing you still don’t understand or one question
you still have
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Plato & Aristotle believed species were fixed &
could be arranged according to their
complexity
In the mid eighteenth century, Carolus
Linnaeus developed a system of classification
that called binomial nomenclature
George Cuvier, in the eighteenth century,
explained changes in the fossil record by
proposing that a whole series of catastrophes
(extinctions) and re-populations from other
regions had occurred giving the appearance of
change over time
Prior to Darwin, it was thought that the world
was young & species did not change