2.  Definition
- gradual change of a population over time
 Types
GEOLOGIC EVOLUTION
-Hutton and Lyell
BIOLOGICAL or ORGANIC EVOLUTION
 The foundation of modern evolutionary thought was
described by Charles Darwin

3. Greek Philosophers
• Plato’s Idealism
• Aristotle’s scala naturae (scale of
nature)
 special creation of each species
 organisms were created in their current
form
 the earth was only a few thousand years
old

4. CARL Von LINNE
 Swedish botanist
 worked on the classification of
plants
 published Species Plantarum
(~7,300 plants)
 ordered classification of plants
based on their similarities
 showed the natural
relationships of plants

5. THOMAS MALTHUS
 economist & clergyman
 published
An Essay on the Principle of
Population
 Populations had an inherent tendency to increase
geometrically, while the resources needed to support this growth
increase slowly or not at all.
 Because of the continued growth of a species would outstrip
needed resources, growth would be limited.

6. JEAN-BAPTISTE de LAMARCK
 French biologist
 proposed that modern species
descended from other species
 Lamarckism based on two theories:
1. Inheritance of Acquired Characteristics
- traits acquired by an individual during its life are passed to its
offspring
2. Use and Disuse
- organs of the body that were used extensively to cope with the
environment became larger and stronger, while organs that
were not used deteriorated

7.  Tendency toward perfection
 Behavior has no effect on heritable
trait
 BUT first to use scientific method in
understanding evolution

8. THE ROAD TO EVOLUTIONARY THEORY
Evolution Before Darwin
Example:
The Evolution of the Giraffe
Giraffes obtained their long necks from
previous giraffes who stretched to eat the
leaves of high tree branches.
Stretching increased the length of their
necks, and this acquired characteristic
was passed to the next generation.

9. Lamarckism
 first to present a unified theory that attempted to explain the
changes in organisms from one generation to the next
 Although, mechanisms proposed for change was wrong, since
acquired characteristics are not heritable!!!
 origin of species from preexisting species
 ability of organisms to adapt

10. GEORGES CUVIER
 French anatomist and
naturalist and writer
 paleontologist
 strongly opposed the
concept of evolution
 history of living organisms recorded in layers of rock
containing a succession of fossil species in chronological
order
 fossils were organisms that had died in a series of
catastrophes, after which extinct plants and animals were
replaced by the immigration of distant species to the
devastated region  Catastrophism

11. JAMES HUTTON
 Scottish geologist
 took up law, medicine
and agriculture
 published
Theory of the Earth
 geological change occurred slowly but continuously by the
process of Gradualism
 sedimentary rock that encased fossils formed by the
gradual accumulation of sediments in bodies of water

12. GEORGES CUVIER
JAMES HUTTON
CHARLES LYELL
Geological evolution
 the earth is very old and constantly changing
 life existed millions of years ago
 geologists were convinced of an ancient earth, but were at
odds over how to explain the appearance and
disappearance of species in the fossil record
 Believed in special creation

13. GREGOR MENDEL
 Austrian biologist
 discovered the basic principles of
heredity
 father of Classical Genetics
 Individual characteristics determined
by inherited factors transmitted from
parent to offspring.

14. CHARLES DARWIN
 voyage on the H.M.S.
Beagle (1836)
 published (1859)
The Origin of Species
 first person who proposed
a mechanistic approach to
evolutionary thought
 the father of synthetic
evolution

16.  Galapagos tortoise
Darwin’s finches
Most organisms on the islands
were endemic.

17.  species not specially created in their
present forms, but had evolved from
ancestral species
 proposed a mechanism for evolution:
Natural Selection
A population of organisms can change
over time as a result of individuals with
certain heritable characteristics
leaving more offspring than other
individuals.

18. ALFRED RUSSELL WALLACE
 English naturalist
 studied the Malay
archipelago and Amazon
 proposed a theory of
evolution similar to Darwin’s
“Then I saw at once that the ever-present variability of all living
things would furnish the material from which, by the mere
weeding out of those less adapted to the actual conditions, the
fittest alone would continue the race.”

19. Darwinism in Historical Context

20. HUGO CARL ERICH VON
DE VRIES CORRENS TSCHERMAK
 rediscovered Mendel’s laws of heredity
 the start of rediscovering evolution in terms of Mendel’s
ideas

21. JAMES WATSON
FRANCIS CRICK
 elucidated the structure of
DNA (genetic material)
 DNA contains coded
information which acts as a
blueprint for the transfer of
hereditary information from
generation to generation
 mutation as the raw
material for evolution