Download Darwin`s Theory

Principles of Biology Lecture Notes
Fall, 2006
EVOLUTION I – DARWIN’S THEORY DEMYSTIFIED
Outline
Ernst Mayer’s Summary of Darwin’s Theory:
5 Observations & 3 Inferences
2 Major Features of Darwin’s Theory
Common Ancestry
Adaption by Natural Selection
Historical Context for Darwin’s theory
Evolution by Natural Selection as a Theory
Synthetic (Unifying)
Predictive
Explanatory
Testable
Darwin’s Theory Develops
Field Work
South America
Galapos
Long Time
Wallace (short time)
Problems with the Acceptance of Darwin’s Theory
EVOLUTION
We now devote the final block of material for the term to an overview of evolution.
Evolution is undoubtedly one of the four or five terms that almost everyone associates with biology,
and with good reason. About fifty years ago, one of the leading biologists of the time stated that
“Nothing in biology makes any sense except in light of evolution”. Unfortunately, there are many
who would have problems with that statement, in part because there is much misunderstanding of
evolution.
Introduction: Darwin’s Theory Demystified
 ERNST MAYER’S
SUMMARY OF
DARWIN’S THEORY:
o Observation #1
o Observation #2
o Observation #3
o Inference #1
o Observation #4
o Observation #5:
o Inference #2
o Inference #3
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Historical context for Darwin’s theory
Learn these contributors, their contributions to our understanding of the origin of the variety of
living systems and the role of the concept in the development of evolutionary thought.
 PLATO
 ARISTOTLE
 CUVIER
 LYELL
 HUTTON
 MALTHUS
 LAMARK.
Darwin’s Theory Develops
Understand how each of the following impacted Darwin’s thinking as he developed, documented and
eventually presented his theory.
 FIELD
WORK IN
SOUTH AMERICA
Niche
Organism
Fossil
Europe
South
America
 FIELD
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WORK IN THE
GALAPAGOS ISLANDS
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
LONG
TIME FOR EVOLUTION TO OCCUR
(FIG 25.17)
HTTP://VCOURSEWARE.SONOMA.EDU/VIRTUALDATING/FILES/1.0_CLOCKSINROCKS.HTML
 WALLACE
Darwin’s Theory
 DARWIN’S
THEORY HAS
2
MAJOR FEATURES:
 DARWIN’S THEORY DOES NOT CONTEND
MONKEYS” - IT DOES PROPOSE
THAT
“HUMANS
DESCENDED FROM
Each of the following have a very specific, defined role in the process of evolution by natural
selection:
 POPULATION
 VARIATION
 CONTINGENCY
 CHANCE
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Evolution by Natural Selection as a Theory
Evolution by natural selection is a scientific theory
with all the best features of an excellent theory.
 EVOLUTIONARY THEORY
IS SYNTHETIC OR
UNIFYING
o Unifies Several types of Evidence
o Biogeography
o The Fossil Record
o Comparative anatomy
o Comparative Embryology
o Comparative Biochemistry
o Artificial Selection
 EVOLUTIONARY THEORY
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IS PREDICTIVE:
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 EVOLUTIONARY THEORY
IS EXPLANATORY:
 EVOLUTIONARY THEORY
IS TESTABLE:
Evidence of the operation of evolution by natural selection:
Industrial Melanism
Appearance of antibiotic resistance
Observations of African lake cichlids
pathogens (Fig 22.12 & 22.13)
Experiments on “guppy size”
Studies of sticklebacks in B.C. lakes
Beak of the Finch” experiments
OR & CA Salamanders (Fig 24.9)
Sources of Problems with the Acceptance of Darwin’s Theory
How widespread is the lack of acceptance of evolution by natural selection?
In the U.S.?
in other countries?
Among the U.S. scientific community? (what, how & why)
Disagreement among scientists about evolution:
Each of the following have been raised as objections to Darwin’s Theory:
(see the book “Discovering Darwin’s God” by Kenneth Miller for a good
summary)
 “THERE HASN’T BEEN SUFFICIENT TIME”
FIG 26.2, 25.2, & 25.17
 “ARGUMENT
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FROM
DESIGN”
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
“NO

“IT’S

“THE GREAT CHAIN

ONE WAS THERE TO SEE EVOLUTION BY NATURAL SELECTION”
ONLY A THEORY”
OF
BEING”
“No new species have been produced by evolution by natural
selection”
What do you mean by a species? pp.465-469
Species Concept
Biological
Definition
Limitations
Morphological
Recognition
Cohesion
Ecological
ALL THESE SPECIES CONCEPTS ARE BASED ON THE FACT THAT A SPECIES
REQUIRES GENETIC ISOLATION
 MICROEVOLUTION OCCURS BUT CANNOT PRODUCE MACROEVOLUTION
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