Evolution

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Evolution Mon, Wed Fri 200 250 pm
Spring Semester 2006
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Evolution 1 2006 Spring
Scientists influencing Darwin
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Evolution 2 2006 Spring
Jean-Baptist Lamarck (1744 -1829) - French z
oologist - ignored or attacked during hi
s lifetime - Lamarck proposed a differen
t mechanism for evolution than Darwin,
but the predicted result is the same
- discredited theory on the inheritance
of acquired traits
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Evolution 3 2006 Spring
Jean-Baptist Lamarck (1744 -1829) Theory of E
volution
First Law - change in the environment changes th
e needs of animals - causes a change in the
ir behavior - altered behavior leads to greater
or lesser use of structures or organs - str
uctures increase/decrease in size over
generations Second Law - such changes are
inheritable
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Evolution 4 2006 Spring
Jean-Baptist Lamarck (1744 -1829)
Change versus no change
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Evolution 5 2006 Spring
Spontaneous generation
Common believes until the middle of the
19th century - large organisms reproduce sexu
ally - small organisms could arise spontaneous
ly from mud or organic matter - when lar
ge animals die they decompose into
smaller animals - members from one species
can magically transform into a differ
ent species example werewolfs
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Evolution 6 2006 Spring
Spontaneous generation
Van Helmont (1577 1644) If you press a piece
of underwear soiled with sweat together with some
wheat in an open mouth jar, after about 21 days
the odor changes and the ferment, coming out of
the underwear and penetrating through the husks
of wheat, changes the wheat into mice.
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Evolution 7 2006 Spring
Spontaneous generation
Van Helmont (1577 1644) But what is more rema
rkable is that mice of both sexes emerge, and
these mice successfully reproduce with mice born
naturally from parents and the mice which com
e out of the wheat and underwear are not small
mice, not even miniature adults or aborted mice,
but adult mice emerge!
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Evolution 8 2006 Spring
Spontaneous generation
Two obstacles to evolutionary concepts
(contradicting) - fixed species concept -
spontaneous creation
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Evolution 9 2006 Spring
Spontaneous generation
Late 17th century Use of experimental methods in
biology had begun Redi (1621 1697) demonst
rated that maggots arise only from eggs laid by
flies, and flies arise only from maggots.
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Evolution 10 2006 Spring
Spontaneous generation
Late 17th century Use of experimental methods in
biology had begun Van Leeuvenhoek (1623 1723
) Microscopic beasties in decaying fermenting
solutions and broth could be explained as
deriving from previously existing particles
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Evolution 11 2006 Spring
Scientists influencing Darwin
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Evolution 12 2006 Spring
Georges Cuvier (1769 1832)
- French anatomist and father of paleontolo
gy - history of life is recorded in geol
ogical strata containing fossils - effect
ive opponent of the evolutionists of his day
s - advocated catastrophism, boundaries
between strata were due to local flood
or drought that destroyed the species then
present
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Evolution 13 2006 Spring
Fossils
- essential for understanding evolutionary
relationships - connection between past and p
resent

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Evolution 14 2006 Spring
Fossils
Riddles Some fossils do not resemble existi
ng species! Some seashells can be found on m
ountaintops http//www.soton.ac.uk/
bam2/col-index/fossi-lindex/Bel-Squid/pages/Belem
nite.htm
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Evolution 15 2006 Spring
Fossils

• Explanations
• Christianity
• The book of Genesis
• - age of the world is calculated by the number
• of generations since Adam
• - can not be older than 4000 to 7000 years
• Fossils
• - lusi nature (jokes of nature)

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Evolution 16 2006 Spring
Fossils
Stratification Placing fossils in a historica
l sequence
Deeper strata are older
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Evolution 17 2006 Spring
Fossils

• Georges Cuvier (1769 1832)
• catastrophism
• Stratification of rock and fossils indicates
• Catastrophes
• Glaciations divine intervention!
• Floods

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Evolution 18 2006 Spring
Cuvier
Extinct species are species, whose place tho
se which exist today have filled, perhaps to be
themselves destroyed and replaced by others
After each catastrophe - divine creation
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Evolution 19 2006 Spring
Scientists influencing Darwin
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Evolution 20 2006 Spring
Sir Charles Lyell (1797 1875)
Born in Scottland Attended Oxford University -
mathematics and geology Knighted for scientif
ic accomplishment Principles of Geology (12 edi
tions). action of the rain, sea, volcanoes and
earthquakes explained the geological history of
more ancient times. http//www.mnsu.edu/emuseum
/information/biography/klmno/lyell_charles.html
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Evolution 21 2006 Spring
Buffon, Lamarck, Lyell
Geological discontinuity represents
gradual changes in the environment
Effects of these changes lead to spec
ies transformation The uniformitarian concep
t
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Evolution 22 2006 Spring
Uniformitarianism

• Helped liberate scientific thinking
• Static universe
• dynamic universe that is historically
  understandable

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Evolution 23 2006 Spring
Uniformitarianism
Change versus no change
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Evolution 24 2006 Spring
Early 19th century
Basic concepts to believe in evolution are
present - geologists perceive the age of the
Earth to be in the range of millions of years
- acceptance of the existence of previously
extinct fossil species - taxonomy - be
lief that organisms descend through
inheritance from previously existing organisms
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Evolution 25 2006 Spring
E
Early 19th century
Two more important questions What mechanism ca
n explain why species change? What hereditary m
echanism could enable organisms to change?