Transcript Chapter 15 Darwin`s Theory of Evolution

Chapter 15
Darwin’s Theory of Evolution
Biology – Fall 2006
Mr. Holmes
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Charles Darwin was the man with ideas that
drove the theory of evolution.
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Darwin was an Englishman who set sail on a
voyage on the H.M.S. Beagle.
While on this trip he made numerous
observations and collected data that led him
to propose a revolutionary hypothesis.
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Evolution is the change over time.
A theory is a well-supported, testable
explanation of a phenomenon that has
occurred in the natural world.
Most of Darwin’s observation come from the
Galapagos Islands near South America.
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One significant observation that Darwin
made is the amount of diversity within a
species.
Another observation was the fact that not all
the same species lived in the same places
(diversity of species in different locations)
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His observations were supported by fossils
that he discovered.
Fossils are preserved remains of ancient
organisms.
Some of the animals that Darwin observed
were finches (beak shape), beetles and
turtles (shell shape).
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Before Darwin proposed his ideas, Charles
Lyell and James Hutton help realized that the
Earth has also undergone geological
changes in the millions of years that it has
existed.
Their work brought Darwin to the realization
that if the Earth could change then life on
Earth can change as well.
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Before the idea of evolution, Jean-Baptiste
Lamark introduced his ideas for the obvious
change over time. They included:
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Tendency toward perfection
Use and disuse
Inheritance of acquired traits
Although, his ideas are incorrect, he paved
the way for the work of later biologists
studying evolution.
 Define
the vocabulary in Section 3
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Darwin wrote a book called On the Origin of Species
Natural variation is simply the variation or differences
that are found within a specie
Artificial selection in the selective breeding of a
particular type of organisms used by farmers and
breeders.
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Struggle for existence is like the idea of
competition, except for in this idea survival or
life is a component. Competing for food
becomes a struggle for life.
Fitness is an individual’s ability to reproduce
in a certain area.
Adaptation is inherited characteristics that
allows an organism to survive (being better
suited for the environment.)
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Survival of the fittest is the idea that specie
are suited for an environment and are able to
reproduce and survive.
Natural selection is a term used to describe
survival of the fittest because this type of
selection is not manipulated by man, but by
nature.
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Descent with modification is the idea that
living things have descended through time
with changes.
Common descent is the principle that all or
many species share a common ancestor in
which they were derived.
Evidence of Evolution
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Fossil Record is the term used to refer to all
fossils that have been discovered and the
information gained from them.
Geographic Distribution of Living Species
Homologous Structures (Structures that have
different functions, but come from the same
embryonic tissue) Example are arms of human,
bird wings, arms of turtles. Vestigial organs are
organs that are homologous, but are extremely
reduced in size.
Homologous Structures
Vestigial Organs
Vocabulary
Evolution
Theory
Fossil
Natural Selection
Struggle for Existence
Fitness
Adaptation
Artificial Selection
Vestigial organ
Common Descent
Homologous structure
Darwin
Lamarck
Descent with modification Lyell
Hutton
Big Bang Theory
Survival of the Fittest
Meteor
Dinosaur(s)