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THE HISTORY
OF LIFE
Biological Evolution
UNIFORMITARIANISM
 Hutton and Lyell
 believes “the present is the key
to the past”
 assumes that the natural
processes governing the earth
today operated at the same
rate throughout history
UNIFORMITARIANISM
 problems
• catastrophes
• creation with apparent age
JEAN LAMARCK
 theory of need
 theory of use and disuse
 theory of inheritance of
acquired characteristics
 basic problem: passing on
acquired characteristics to
future generations
CHARLES DARWIN
 On the Origin of Species by
Means of Natural Selection
(1859)
DARWIN’S THEORY
 descent with modification
common ancestor
 theory of natural selection
• artificial selection
• natural selection
 survival of the fittest
DARWIN’S THEORY
 problems
• Natural selection regroups
existing characteristics.
• No new genetic information
is created.
CHARLES DARWIN
 On the Origin of Species by
Means of Natural Selection
(1859)
 The Descent of Man
(1871)
GEOLOGIC
COLUMN
the sequence of
fossil-containing rock
layers that shows the
supposed rate of
evolution
DATING METHODS
 also use the principles of
uniformitarianism
 radiometric dating methods
measure the decay of a
radioactive substance into a
nonradioactive substance
HUGO DE VRIES
 Species and Varieties:
Their Origin by Mutation
 used the term
“mutations”
NEO-DARWINISM
 mutation-selection theory
 blends Darwin’s theory of
natural selection and de Vries’s
theory of mutations
MUTATIONS & EVOLUTION
 Mutations are random.
 Mutations must occur in
reproductive cells.
 Evolution requires “good
mutations.”
• happening repeatedly
• in many, many organisms
MUTATIONS & EVOLUTION
 Too many mutations will
kill an organism.
genetic load
PUNCTUATED
EQUILIBRIUM
During some periods
of time, evolution
occurred rapidly,
while at other times,
very little evolution
took place.
HOMOLOGOUS
STRUCTURES
organs that are similar
in structure and
function in two
different organisms
CONVERGENT
EVOLUTION
evolution of a similar
structure in
unrelated species
VESTIGIAL
STRUCTURES
organs which no longer
have any function