Transcript Adaptation PPT - Bibb County Schools

Natural Selection
http://evolution.berkeley.edu/evolibrary/home.php
http://evolution.berkeley.edu/evolibrary/home.php
www.darwinday.org/englishL/life/beagle.html
www.darwinday.org/englishL/life/beagle.ht
Used by permission of Darwin Day
Celebration (at DarwinDay.org), 2006
I have called this principle, by which
each slight variation, if useful, is preserved,
by the term Natural Selection.
—Charles Darwin from "The Origin of Species"
http://evolution.berkeley.edu/evolibrary/home.php
Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.
CHARLES DARWIN – 1809-1882
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English
Traveled around the world on the Beagle (ship)
Most of trip was among the Galapagos Islands
Believed that the earth was 6000 years old and
that all plants and animals were unchangeable
over time
During his travels, he observed many live species,
as well as fossils
He did not understand why some species survived
while others were going extinct
These ideas went directly against his beliefs
Darwin’s Observations
• From island to island, he noticed that the
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species of mockingbird, finches, and other
animals varied.
Many of the species Darwin collected had not
yet been discovered or classified
Darwin took his collections and drawings home
and after reading essays and studies by many
other scientists (Gould & Mathus), he developed
the idea of natural selection
5 Principles of Natural Selection
1. Individuals in a population show variation.
2. Variations can be inherited.
3. Organisms have more offspring that can
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survive under normal circumstances.
Variations that increase reproductive
success will have a greater chance of being
passed on from generation to generation.
A population will slowly change over time in
response to the environment.
Darwin…
• By 1840, Darwin had developed the theory of
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natural selection.
He then published “On the Origin of Species by
Means of Natural Selection”
• On the last page of this book, he called his theory
“evolution”
– Evolution is what the process is called ~ natural
selection is HOW evolution happens
• Another researcher, Wallace, also wrote a similar
book at the same time and both books were
published and presented to the scientific
community.