Early ideas about evolution
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What is evolution?
It is the process of biological change by
which descendants come to differ from
their ancestors.
Evolution is an attempt
to explain the origins of
living things, including humans.
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Early years
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Much of today’s understanding of
evolution is based on Charles
Darwin.
What do you think about when you
hear his name?
The father of modern evolution
Images of monkeys turned to men
A universe unguided by any divine
hand
A view of life that is always changing
Early years- 1700’s
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Linnaeus developed
both a binomial system
for naming organisms
and a hierarchy of
classification groupings.
Taxonomy originated in
the work of Linnaeus.
Cuvier, Fossils, and Catastrophism
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Fossils are remnants or impressions of organism
laid down in sedimentary rocks
Fossils from strata of different ages reveal that a
succession of organisms has existed on earth.
Cuvier is considered the father of paleontology.
Advocating catastrophism, he maintained that
the differences he observed in the fossils found
in different strata were the result of local
catastrophic events such as floods or drought
and were not indicative of evolution.
Geologic gradualism
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Gradualism, result of a slow continuous
process, was proposed by James Hutton in
1795 to explain the geologic state of the
earth.
Darwin took the ideas from the
observations of Hutton: The Earth must be
very old if geologic change is slow and
gradual, and very slow processes can
produce substantial change.
Thomas
Malthus
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1798 published Essay on the Principle of
Population
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gave Darwin idea that populations
produce more offspring than can survive
because populations increase faster than
earth can support
Lamarck
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Lamarck published a theory of
evolution in 1809 (same year
Darwin was born). He
explained the mechanism of
evolution with two principles.
the use or disuse of body
parts leads to their
development or deterioration,
acquired characteristics can
be inherited.
Charles Lyell
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Proposed geological theory of
uniformitarianism which is different from
catastrophism.
Uniformitarianism- the events in the past
that formed the Earth are still at play
today and are a gradual process
Principles of Geology was published,
Darwin read and agreed with the findings.
Charles Lyell Continued
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He studied sedimentary rock and how the layers
(strata) of the Earth form.
He said that these processes take thousands of
years to occur.
Darwin used this information to conclude that if
the different layers of the Earth take thousands
of years to form, then the different fossils found
in each layer must’ve taken thousands of years
to change or evolve.
Charles Lyell Cont.
Voyage of the Beagle
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Darwin was 22 years old when he sailed
from Great Britain on the H.M.S. Beagle in
1831.
He spent the voyage collecting thousands
of specimens of the fauna and flora,
observing various adaptations of
organisms. He was particularly struck by
the uniqueness of the fauna of the
Galapagos Islands
Darwin and Wallace
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In the 1830’s Darwin starts compiling his
work and another scientist, Alfred Wallace,
was also working on a theory of natural
selection.
Before publishing his findings, Wallace
sends a copy of his work to Darwin in
1858.
To Darwin’s surprise, Wallace has
formulated a very similar theory!
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Both findings were presented to the Linnaean
Society in 1858.
Darwin’s Origin of Species was published in 1859
(yes! 20 years after he wrote it!), Wallace will
continue his travels and research
Wallace’s theory and name will forever stand in
the shadow of Darwin and the theory of
evolution
Best Seller!
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Darwin’s book was a success, however,
natural selection was still questioned even
by Darwinist
In 1865 Mendel’s findings on heredity
were published
However, it would take until the 1900’s
before the findings were revisited
Charles Darwin dies in 1882 and is buried
in Westminster Abbey