• Lamarck: Populations change as individuals
change in response to environment
• Darwin: Populations change as individuals
experience different reproductive success
(based on environment) = Natural Selection
1
All living things have much in common, in their
chemical composition, their germinal vesicles,
their cellular structure, and their laws of growth
and reproduction… Therefore I should infer…
that probably all the organic beings which
have ever lived on this earth have descended
from some one primordial form, into which life
was first breathed
Darwin, 1859, pg. 484,
“On the Origin of Species”
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3
4
Charles Darwin
• What were his two great contributions to
biology?
5
The Modern Synthesis
(aka Neo-Darwinism)
• 1930’s
• Math + genetics + natural selection
6
Fisher
Wright
7
J. B. S. Haldane
• Asked by theologians, what could
be inferred about the mind of the
Creator from the works of His
Creation, he reportedly replied,
"An inordinate fondness for
beetles”.
• "My own suspicion is that the
universe is not only queerer than
we suppose, but queerer than we
can suppose."
8
Other Players in the Modern Synthesis
Ernst Mayr
Allopatric speciation model
Animal speciation
George Gaylord Simpson
Fossils consistent with evolution
G. Ledyard Stebbins
Genetics and plant speciation
• Dobzhansky,
1990-1975
• “Nothing in
biology makes
sense except in
the light of
evolution”
From the Modern
Evolutionary
Synthesis
Facebook page
“Modern Synthesis”
coined by Julian
Huxley
= grandson of Thomas Henry
Huxley (Darwin’s bulldog)
=brother of Aldous Huxley
The Evolving Synthesis?
Modern Evolution
• What do we have now that Darwin didn’t?
• Read Futuyma’s definition
13
"In the broadest sense, evolution is merely
change, and so is all-pervasive; galaxies,
languages, and political systems all evolve.
Futuyma’s definition, part 1
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Biological evolution (or organic evolution)
is change in the properties of populations
of organisms that transcend the lifetime of
a single individual. The ontogeny of an
individual is not considered evolution;
individual organisms do not evolve.
Futuyma’s definition, part 2
15
The changes in populations that are
considered evolutionary are those that are
inheritable via the genetic material from
one generation to the next.
Futuyma’s definition, part 3
16
Biological evolution may be slight or
substantial; it embraces everything from slight
changes in the proportion of different alleles
within a population (such as those determining
blood types) to the successive alterations that
led from the earliest protoorganism to snails,
bees, giraffes, and dandelions.”
--Futuyma, 1986
Futuyma’s definition, part 4
17
• Assignment: Break down and shorten
Futuyma’s definition
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• At this point, we talked a bit about the
evidence for common ancestry, but I have
moved those slides to the Day 4
presentation...