Download History of Evolutionary Thought

History of
Evolutionary
Thought
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Early Ideas On Earth’s
Organisms
Aristotle (350 bc)
was a Greek
philosopher who
believed every
species was
designed for a
purpose.
 Organisms were
not that way by
chance.
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He classified
organisms according
to their complexity,
with plants as the
least complex and
humans as the most.
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Early Ideas On Earth’s
Organisms
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Linnaeus (1730s)
was the 1st to
group similar
organisms and
assign them Latin
names.
Two-word name:
Genus & Species
Naming system
known as binomial
nomenclature.

Our name:
Homo sapiens
(wise person)
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Malthus – In 1798 publishes “An
Essay on the Principle of
Population,” where he theorized
that a growing population would
eventually outgrow all of their
resources.
 The carrying capacity of a
population is determined by limited
resources.
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Theories of Geologic Change

Hutton – Theory of Gradualism
(1795): the idea that landforms
were shaped by very slow changes
over a long period
of time, and
not by natural
disasters.
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Lyell – Theory of Uniformitarianism
(1830): the idea that the same
processes that shaped landforms in
the past also shape landforms
today.
Geologic processes that shape Earth
are uniform, or the same, through
time
Proposed that the Earth was
millions of years old instead of a
few thousand years old
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Jean–Baptiste Lamarck’s
Theory of Evolution
One of the first
scientists to
understand that
change occurs over
time.
 1809 – proposed that
all organisms evolve
toward perfection and
complexity
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Jean–Baptiste Lamarck’s
Theory of Evolution
Stated that changes in an
environment caused an organism’s
behavior to change
 This change led to greater use or
disuse of a structure or organ, and
the structure would become larger
or smaller as a result
 Said acquired changes were passed
on to offspring

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Lamarck’s Theory of Use and Disuse

If a body part
were used, it
got bigger and
stronger
– Lamarck thought that
the long necks of
giraffes evolved as
generations of giraffes
reached for higher
leaves in the trees

If body part
NOT used, it
deteriorated
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Lamarck’s Theory of Inheritance
of Acquired
Characteristics/Traits
Proposed that by selective use and
disuse of organs, organisms
acquired or lost certain traits
during their lifetime
 These traits were then passed on
to their offspring
 Over time this led to new species!
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Lamarck’s Mistakes
 Lamarck
did NOT know how
traits were inherited
– We now know traits are passed
through genes
 Genes
are NOT changed by
activities in life
 Change through gene mutation
occurs before an organism is
born
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Alfred Wallace
Organisms evolved
from common
ancestors
 Observed plants and
animals with Darwin
 Jointly presented
ideas with Darwin in
1858

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Charles Darwin
Observed Tortoises and Finches on the
Galapagos Islands
 Published book titled “On the Origin of
Species by Means of Natural Selection”
(1859)

– Identified 4 principles associated with
Natural Selection
» Variation
» Overproduction
» Adaptation
» Descent with Modification
Timeline
You’re going to make a timeline for
the History of Evolutionary Theory.
 Lay paper sideways. Draw a
horizontal line.
 Include the year, scientist’s name, &
summary of their contribution.

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