II. The History of Evolutionary Thought

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II. The History of Evolutionary Thought A.
Early Greeks B. 2nd Greek School C. The
Impact of Christianity D. The Renaissance
(1400-1700) E. The Enlightenment (1700s)
F. The Battle in France (1780's-1830's)
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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) a. Early Career -
wrote a four-volume flora of France - Buffon
selected him to be his son's tutor - 1788 -
Buffon got him a position in the Botany Dept. of
the Natural History Museum - believed in the
fixity of species.
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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) b. 1793 -
Appointed Professor of Invertebrates - found
living molluscs that were similar to fossil forms
- could array some species in nearly continuous
lineages from the Tertiary (65 mya) to present -
concluded that species change over time.
c. 1809 - Philosophie Zoologique
(culminating work) - animals series of
perfection towards man (Scala naturae) - change
through time (lineage evolution)
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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) d. Mechanisms of
Change use and disuse inheritance of
acquired characteristics innate potential,
given by Creator, to become progressively more
complex. - Interactions with the environment
causes a NEED Organism uses some organs
more Organism changes during its lifetime
passes modification to offspring
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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) e. Solves the
Extinction Problem - Previous solutions were
- all extinct species were killed by Noah's
flood - might live elsewhere (and NOT be
extinct) - it is the work of humans, not
God.
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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) e. Solves the
Extinction Problem change without extinction,
or loss of harmony
E F G H
A B C D
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"May it not be possible that the fossils in
question belong to species still existing, but
which have changed since that time and have been
converted into that similar species that we now
actually find?" - Lamarck (1809)
E F G H
A B C D
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f. Summary of Lamarcks contributions - First to
commit to evolution as historical fact - First
to propose a testable mechanism of change -
Uniformitarian approach - Support for ancient
Earth - Courage to include humans
"Lamarck was the first man whose conclusions on
the subject excited much attention. This justly
celebrated naturalist first published his views
in 1801. . . he first did the eminent service of
arousing attention to the probability of all
changes in the organic, as well as in the
inorganic world, being the result of law, and not
of miraculous interposition." - 1861
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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) 2. Geoffroy
Saint-Hilaire (1772-1844)

• was vertebrate zoologist at Museum of Natural
  History with Lamarck.
• Invited Georges Cuvier to join him in 1794.
• There were 'unities of type' among organisms -
  homologous structures
• form constrains function, but form is malleable
• - the form responds to environment

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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) 2. Geoffroy
Saint-Hilaire (1772-1844)
"The external world is all-powerful in alteration
of the form of organized bodies.. . these
modifications are inherited, and they influence
all the rest of the organization of the animal,
because if these modifications lead to injurious
effects, the animals which exhibit them perish
and are replaced by others of a somewhat
different form, a form changed so as to be
adapted to the new environment."

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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) 2. Geoffroy
Saint-Hilaire (1772-1844)
What can be more curious than that the hand of a
man, formed for grasping, that of a mole for
digging, the leg of the horse, the paddle of the
porpoise, and the wing of the bat, should all be
constructed on the same pattern, and should
include the same bones, in the same relative
positions? Geoffroy St. Hilaire has insisted
strongly on the high importance of relative
connexion in homologous organs the parts may
change to almost any extent in form and size, and
yet they always remain connected together in the
same order.

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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) 2. Geoffroy
Saint-Hilaire (1772-1844) 3. Georges Cuvier
(1769-1832)
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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) 2. Geoffroy
Saint-Hilaire (1772-1844) 3. Georges Cuvier
(1769-1832)
a. Arguments against Lamarckian evolution -
organisms are functional 'wholes change in an
organ would stop its function - and use and
disuse were not heritable - extinction
is real
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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) 2. Geoffroy
Saint-Hilaire (1772-1844) 3. Georges Cuvier
(1769-1832)
b. Accomplishments in Biology - Founded
comparative anatomy as a discipline - Founded
vertebrate paleontology as a discipline -
split the Scala into four embranchments
Vertebrata Articulata (Arthropoda and
Annelida) "Mollusca" (Molluscs and other
bilateral inverts) Radiata (Cnidaria and
Echinodermata)
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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) 2. Geoffroy
Saint-Hilaire (1772-1844) 3. Georges Cuvier
(1769-1832)
c. Accomplishments in Paleontology - Accepted
William Smith's observations that each strata had
it's own distinct fossil assemblage (faunal
succession). - Fossils in upper strata are more
similar to extant (living) species than fossils
in lower strata. - Validated extinction -
believed that Mammoths could not be hiding
elsewhere.
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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) 2. Geoffroy
Saint-Hilaire (1772-1844) 3. Georges Cuvier
(1769-1832)
d. Debates with St. Hilaire - 8 debates in 1830
- showed that arthropods and vertebrates were
only superficially similar.. no unity of type
across all animals - showed that Egyptian
mummified cats were no different from modern cats
in morphology... no change over time. -
Professes a "functionalist" approach - structure
follows function, and cannot be modified without
losing that function
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F. The Battle in France (1780's-1830's) 1.
Jean Baptiste Pierre Antoine de Monet, Chevalier
de Lamarck (1744-1829) 2. Geoffroy
Saint-Hilaire (1772-1844) 3. Georges Cuvier
(1769-1832) 4. Conclusions of the
Period While Cuvier "won" the debate and also
beat back Larmarck's ideas, evolutionary ideas
were now prominently discussed.
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A Darwinian View of Life I. Overview - Darwin
(1859) Origin of Species - Mendel (1865)
Experiments in Plant Hybridization - Flemming
(1878) Describes chromatin and mitosis
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II. Darwins Contributions A. Overview 1. Life -
Born Feb 12, 1809 - Graduated Cambridge,
intending to join the clergy - 1831-36,
Naturalist on H.M.S. Beagle - 1859 The Origin of
Species - Died April 19, 1882, interred in
Westminster Abbey
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II. Darwins Contributions A. Overview 1.
Life 2. The Origin of Species (1859)
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II. Darwins Contributions A. Overview 1.
Life 2. The Origin of Species (1859) a. One
Long Argument - observations leading to
the conclusions that - life changes
through time - species descend from shared
ancestors
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Figure from The Origin of Species (1859)
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II. Darwins Contributions A. Overview 1.
Life 2. The Origin of Species (1859) a. One
Long Argument b. Mechanism explaining HOW
evolution occurs - Natural Selection
c. Dilemmas challenges and apparent
inconsistencies
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II. Darwins Contributions A. Overview B.
Argument Evidence for Evolution by Common Descent
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II. Darwins Contributions A. Overview B.
Argument Evidence for Evolution by Common
Descent 1. Geology a. James Hutton (1726-1797)
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B. Argument Evidence for Evolution by Common
Descent 1. Geology a. James Hutton
(1726-1797)
- observed Hadrians Wall, but by the Roman
Emperor Hadrian in 122 A.D. 1600 years old, but
no sign of erosion. How much older must highly
worn and eroded granite outcrops be?
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B. Argument Evidence for Evolution by Common
Descent 1. Geology a. James Hutton
(1726-1797)
- observed the White Cliffs of Dover huge
coccolith deposits. If sedimentation was slow
and steady as it is today (uniformitarianism),
how long would it take to create such a deposit?
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B. Argument Evidence for Evolution by Common
Descent 1. Geology a. James Hutton
(1726-1797) - Observed and interpreted the
unconformity at Siccar Point
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Process 1. Initial depositional cycle
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Process 2. uplift (time)
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Process 3. erosion (time)
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Process 4. second depositional cycle (time)
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B. Argument Evidence for Evolution by Common
Descent 1. Geology a. James Hutton
(1726-1797) - the rock cycles, so the earth
has no vestige of a beginning, no prospect of an
end. THE EARTH IS REALLY REALLY OLD
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B. Argument Evidence for Evolution by Common
Descent 1. Geology a. James Hutton
(1726-1797) b. Charles Lyell (1797-1875) -
Principles of Geology (1831-33) - promoted
uniformitarianism - Darwins friend
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B. Argument Evidence for Evolution by Common
Descent 1. Geology 2. Paleontology a. New
types of organisms are added through the fossil
record
recent
Mammals
Birds
Reptiles
Amphibians
Jawed fishes
Jawless fishes
past
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2. Paleontology a. New types of organisms are
added through the fossil record b. Within a
lineage, there are progressive changes through
time. The fossils in recent strata are more
similar to existing species than fossils in older
(deeper) strata.
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B. Argument Evidence for Evolution by Common
Descent 1. Geology 2. Paleontology 3.
Comparative Anatomy
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B. Argument Evidence for Evolution by Common
Descent 1. Geology 2. Paleontology 3.
Comparative Anatomy a. Homologous Structures
Same structure, but different uses in different
environments (correlated pattern)
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3. Comparative Anatomy a. Homologous
Structures b. Analogous Structures
Different structures, but same uses in the same
environment. (again, a correlation between
anatomy and environment)
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3. Comparative Anatomy a. Homologous
Structures b. Analogous Structures c.
Vestigial Structures
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3. Comparative Anatomy a. Homologous
Structures b. Analogous Structures c.
Vestigial Structures
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3. Comparative Anatomy a. Homologous
Structures b. Analogous Structures c.
Vestigial Structures d. Embryology
Whale embryo w/leg buds
photo
Haeckel (after Darwin)
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B. Argument Evidence for Evolution by Common
Descent 1. Geology 2. Paleontology 3.
Comparative Anatomy 4. Biogeography a.
Convergent Communities
In similar environments, there are organisms that
fill similar ecological roles and they are
morphologically similar (in an analogous, not
homologous, manner). Correlated patterns
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B. Argument Evidence for Evolution by Common
Descent 4. Biogeography a. Convergent
Communities b. Island Communities
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B. Argument Evidence for Evolution by Common
Descent 4. Biogeography a. Convergent
Communities b. Island Communities
Uniqueness of inhabitants correlates with the
degree of isolation. - Galapagos species
different from mainland - Fauklands species
same as mainland
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B. Argument Evidence for Evolution by Common
Descent 4. Biogeography a. Convergent
Communities b. Island Communities
The Galapagos Archipelago
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Voyage of the Beagle Darwin (1845) "The
natural history of these islands is eminently
curious, and well deserves attention. Most of the
organic productions are aboriginal creations,
found nowhere else
Flightless Cormorant
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there is even a difference between the
inhabitants of the different islands yet all
show a marked relationship with those of America,
though separated from that continent by an open
space of ocean, between 500 and 600 miles in
width.
Green Iguana Central and South America
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The archipelago is a little world within
itself, or rather a satellite attached to
America, whence it has derived a few stray
colonists, and has received the general character
of its indigenous productions. Considering the
small size of the islands, we feel the more
astonished at the number of their aboriginal
beings, and at their confined range.
Galapagos Land Iguana, pallid species, only on
Santa Fe island.
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Seeing every height crowned with its crater,
and the boundaries of most of the lava streams
still distinct, we are led to believe that within
a period geologically recent the unbroken ocean
was here spread out.
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Hence, both in space and time, we seem to be
brought somewhat near to that great fact -- that
mystery of mysteries -- the first appearance of
new beings on this earth. The Voyage of the
Beagle Charles Darwin
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B. Argument Evidence for Evolution by Common
Descent 4. Biogeography a. Convergent
Communities b. Island Communities -
Uniqueness correlates with degree of isolation
- Dominated by dispersive forms
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B. Argument Evidence for Evolution by Common
Descent 4. Biogeography a. Convergent
Communities b. Island Communities -
Uniqueness correlates with degree of isolation
- Dominated by dispersive forms - Variation
among islands
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- Finches
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"Seeing this gradation and diversity of structure
in one small, intimately related group of birds,
one might really fancy that from an original
paucity of birds in this archipelago, one species
had been taken and modified for different ends."
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B. Argument Evidence for Evolution by Common
Descent 4. Biogeography a. Convergent
Communities b. Island Communities -
Uniqueness correlates with degree of isolation
- Dominated by dispersive forms - Variation
among islands
The fact that islands are populated by dispersive
forms suggests that they came from populations on
the mainland. However, the species on the
islands are different from the mainland species.
So, if the species originally came from the
mainland, they must have changed through time to
become the species we see today.
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- Mockingbirds
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- Mockingbirds Darwin classified four varieties
of one species
One species
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- Mockingbirds John Gould, the premiere
ornithologist of the day, classified these as
four species
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- Mockingbirds Darwin began to think could the
variation WITHIN species eventually lead to
variation BETWEEN species?
Could organisms in a species become so different
that they become different species?
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Darwin's Mockingbirds
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B. Argument Evidence for Evolution by Common
Descent 5. Argument for Evolution as
Historical Fact P1 Species that are alive today
are different from those that have lived
previously. P2 Spontaneous Generation is
refuted, so organisms only come from other
organisms. C1 Thus, the organisms alive today
must have come from those pre-existing, yet
different, species. C2
There must have been change through time
(evolution). Corollary The fossil record,
vestigial organs, and homologies are all
explicable and logical in this context, and
inexplicable (even heritical) in some theological
contexts (imperfection).
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II. Darwins Contributions A. Overview B.
Argument Evidence for Evolution by Common
Descent C. Mechanism Natural Selection
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• C. Mechanism Natural Selection
• Transitional Observations
• a. Artificial Selection and Domesticated
  Animals and Plants

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• C. Mechanism Natural Selection
• Transitional Observations
• a. Artificial Selection and Domesticated
  Animals and Plants

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• C. Mechanism Natural Selection
• Transitional Observations
• a. Artificial Selection and Domesticated
  Animals and Plants

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• C. Mechanism Natural Selection
• Transitional Observations
• a. Artificial Selection and Domesticated
  Animals and Plants

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• C. Mechanism Natural Selection
• Transitional Observations
• a. Artificial Selection and Domesticated
  Animals and Plants

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• C. Mechanism Natural Selection
• Transitional Observations
• a. Artificial Selection and Domesticated
  Animals and Plants

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• C. Mechanism Natural Selection
• Transitional Observations
• a. Artificial Selection and Domesticated
  Animals and Plants

Selection can create phenotypes beyond the
initial range of expression.. There are no adult
wolves as small as chihuahuas.
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• C. Mechanism Natural Selection
• Transitional Observations
• a. Artificial Selection and Domesticated
  Animals and Plants
• b. 1938 reading Malthus Essay on the
  Principle of Population

In October 1838, that is, fifteen months after I
had begun my systematic enquiry, I happened to
read for amusement Malthus on Population - The
Autobiography of Charles Darwin 1809-1882 (Barlow
1958).
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• C. Mechanism Natural Selection
• Transitional Observations
• a. Artificial Selection and Domesticated
  Animals and Plants
• b. 1938 reading Malthus Essay on the
  Principle of Population

Thomas Malthus (1766-1834) Essay On the
Principle of Population (1798)
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• C. Mechanism Natural Selection
• Transitional Observations
• a. Artificial Selection and Domesticated
  Animals and Plants
• b. 1938 reading Malthus Essay on the
  Principle of Population

Thomas Malthus (1766-1834) Essay On the
Principle of Population (1798) P1 All
populations have the capacity to
over-reproduce P2 Resources are finite C
There will be a struggle for existence most
offspring born will die before reaching
reproductive age.
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• C. Mechanism Natural Selection
• Transitional Observations
• a. Artificial Selection and Domesticated
  Animals and Plants
• b. 1938 reading Malthus Essay on the
  Principle of Population

In October 1838, that is, fifteen months after I
had begun my systematic enquiry, I happened to
read for amusement Malthus on Population and
being well prepared to appreciate the struggle
for existence which everywhere goes on from
long-continued observation of the habits of
animals and plants, it at once struck me that
under these circumstances favourable variations
would tend to be preserved, and unfavourable ones
to be destroyed. The result of this would be the
formation of new species. Here, then, I had at
last got a theory by which to work - The
Autobiography of Charles Darwin 1809-1882 (Barlow
1958).
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• C. Mechanism Natural Selection
• Transitional Observations
• 2. The Theory of Natural Selection

P1 All populations have the capacity to
over-reproduce P2 Resources are finite C
There will be a struggle for existence most
offspring born will die before reaching
reproductive age.
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• C. Mechanism Natural Selection
• Transitional Observations
• 2. The Theory of Natural Selection

P1 All populations have the capacity to
over-reproduce P2 Resources are finite C
There will be a struggle for existence most
offspring born will die before reaching
reproductive age.
P3 Organisms in a population vary, and some of
this variation is heritable
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• C. Mechanism Natural Selection
• Transitional Observations
• 2. The Theory of Natural Selection

P1 All populations have the capacity to
over-reproduce P2 Resources are finite C
There will be a struggle for existence most
offspring born will die before reaching
reproductive age.
P3 Organisms in a population vary, and some of
this variation is heritable C2 As a result of
this variation, some organisms will be more
likely to survive and reproduce than others
there will be differential reproductive success
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• C. Mechanism Natural Selection
• Transitional Observations
• 2. The Theory of Natural Selection

P1 All populations have the capacity to
over-reproduce P2 Resources are finite C
There will be a struggle for existence most
offspring born will die before reaching
reproductive age.
P3 Organisms in a population vary, and some of
this variation is heritable C2 As a result of
this variation, some organisms will be more
likely to survive and reproduce than others
there will be differential reproductive
success. C3 The population change through time,
as adaptive traits accumulate in the population.
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• C. Mechanism Natural Selection
• Transitional Observations
• 2. The Theory of Natural Selection

P1 All populations have the capacity to
over-reproduce P2 Resources are finite C
There will be a struggle for existence most
offspring born will die before reaching
reproductive age.
P3 Organisms in a population vary, and some of
this variation is heritable C2 As a result of
this variation, some organisms will be more
likely to survive and reproduce than others
there will be differential reproductive
success. C3 The population change through time,
as adaptive traits accumulate in the
population. Corollary Two populations, isolated
in different environments, will diverge from one
another as they adapt to their own environments.
Eventually, these populations may become so
different from one another that they are
different species.
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• C. Mechanism Natural Selection
• Transitional Observations
• The Theory of Natural Selection
• "It is interesting to contemplate an entangled
  bank, clothed with many plants of many kinds,
  with birds singing on the bushes, with various
  insects flitting about, and with worms crawling
  through the damp earth, and to reflect that these
  elaborately constructed forms, so different from
  each other, and dependent on each other in so
  complex a manner, have all been produced by laws
  acting around us. These laws, taken in the
  largest sense, being Growth with Reproduction
  Inheritance which is almost implied by
  reproduction Variability from the indirect and
  direct action of the external conditions of life,
  and from use and disuse a Ratio of Increase so
  high as to lead to a Struggle for Life, and as a
  consequence to Natural Selection, entailing
  Divergence of Character and the Extinction of
  less-improved forms. Thus, from the war of
  nature, from famine and death, the most exalted
  object which we are capable of conceiving,
  namely, the production of the higher animals,
  directly follows. There is grandeur in this view
  of life, with its several powers, having been
  originally breathed into a few forms or into one
  and that, whilst this planet has gone cycling on
  according to the fixed law of gravity, from so
  simple a beginning endless forms most beautiful
  and most wonderful have been, and are being,
  evolved". - The Origin of Species (Darwin 1859).