Download 15-1 (Part 2) Ideas That Shaped Darwin`s Thinking

15-1 (Part 2) Ideas
That Shaped Darwin's
Thinking
Linnaeus (classification)
Hutton (gradual geologic change)
Lamarck (species can change)
Malthus (population limits)
Cuvier (fossils, extinction)
Lyell (modern geology)
Darwin (evolution, natural selection)
Mendel (inheritance)
American Revolution
1750
Wallace (evolution, natural selection)
U.S. Civil War
French Revolution
1850
1900
1800
1795 Hutton proposes his theory of gradualism.
1798 Malthus publishes “Essay on the Principle of Population.”
1809 Lamarck publishes his theory of evolution.
1830 Lyell publishes Principles of Geology.
1831–1936 Darwin travels around the world on HMS Beagle.
1837 Darwin begins his notebooks on the origin of species.
1844 Darwin writes his essay on the origin of species.
1858 Wallace sends his theory to Darwin.
1859 The Origin of Species is published.
1865 Mendel publishes inheritance papers.
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Ideas That Shaped
Darwin's Thinking
An Ancient, Changing Earth
An Ancient, Changing Earth
How did Hutton and Lyell describe
geological change?
Ideas That Shaped
Darwin's Thinking
An Ancient, Changing Earth
Hutton and Lyell helped scientists
recognize that Earth is many millions of
years old, and the processes that
changed Earth in the past are the same
processes that operate in the present.
Copyright Pearson Prentice Hall
Ideas That Shaped
Darwin's Thinking
• Gradualism
Ideas That Shaped
Darwin's Thinking
An Ancient, Changing Earth
Lyell's Principles of Geology
Lyell stressed that scientists must explain past
events in terms of processes that they can actually
observe.
The processes that shaped the Earth millions
of years earlier continue in the present.
Ideas That Shaped
Darwin's Thinking
An Ancient, Changing Earth
This understanding of geology influenced
Darwin:
• If the Earth could change over time, life might
change as well.
• It would have taken many years for life to change
in the way Lyell suggested.
This would have been possible only if the Earth
were extremely old.
Ideas That Shaped
Darwin's Thinking
Population Growth
What was Malthus's theory of
population growth?
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Ideas That Shaped
Darwin's Thinking
Population Growth
Malthus reasoned that if the human
population continued to grow
unchecked, sooner or later there would
be insufficient living space and food for
everyone.
Ideas That Shaped
Darwin's Thinking
Lamarck’s Evolution Hypotheses
According to Lamarck, how did species
evolve?
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Ideas That Shaped
Darwin's Thinking
Lamarck's Evolution Hypotheses
Lamarck's Evolution Hypotheses
Jean-Baptiste Lamarck recognized that:
• living things have changed over time.
• all species were descended from other
species.
• organisms were adapted to their environments.
Copyright Pearson Prentice Hall
Ideas That Shaped
Darwin's Thinking
Lamarck's Evolution Hypotheses
Lamarck proposed:
That by selective use or disuse of
organs, organisms acquired or lost
certain traits during their lifetime. These
traits could then be passed on to their
offspring.
Flaw:
Use and Disuse
Ideas That Shaped
Darwin's Thinking
Lamarck’s Evolution
Ideas That Shaped
Darwin's Thinking
A male fiddler
crab uses its front
claw to ward off
predators and to
attract mates.
Lamarck's Evolution Hypotheses
Lamarck's Hypothesis
Ideas That Shaped
Darwin's Thinking
Because the front
claw is used
repeatedly, it
becomes larger.
This characteristic
(large claw) is
passed onto its
offspring.
Lamarck's Evolution Hypotheses
Lamarck's Hypothesis
Ideas That Shaped
Darwin's Thinking
Lamarck's Evolution Hypotheses
Evaluating Lamarck's Hypotheses
Lamarck’s hypotheses of evolution are
incorrect in several ways.
Lamarck did not know:
• how traits are inherited.
• that an organism’s behavior has no effect on
its heritable characteristics.
However, he paved the way for the work of later
biologists.