Riyad A. Sadek, April 3, 2006
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CIVILIZATION SEQUENCE PROGRAM (CVSP 206)
DARWIN, DARWINISM AND EVOLUTION
I. BEFORE DARWIN
a. Greek Philosophy:
 Plato’s Essentialism/Idealism/Typology,
 Aristotle’s (Founder of biology) Scala naturae; Teleology
b. Christian Theology:
 Literal interpretation of the Bible; fixity of living things; Creatures are perfect, being God’s
Creation; incorporating Platonic and Aristotelian philosophies (The Ladder of Nature; the
Great Chain of Being); The age of the Earth 4004 years. Fossils regarded as lusus naturae or
“jokes of nature”.
c. Challenges from empirical science:
 Newton: mechanistic theories of physical phenomena.
 Geology: fossils (i.e. extinction of species), the challenge to the immutability of the world.
Sediments laid down at different times.
 French naturalist Buffon, 1799: earth very old (168,0000-500,000 years).
 Cuvier, early 1800’s: Catastrophism (species went extinct as a result of repeated catastrophes).
 Hutton, 1788: Uniformitarianism (the same processes are responsible for both past and present
events; Earth is very old, “No vestige of a beginning, no prospect of an end”).
 Thomas Malthus 1798: An Essay on the Principle of Populatin, (as populations increase their
resources become scarcer and that leads to shortages of food, famine, diseases, war etc)
 Charles Lyell, 1830-33- Principles of Geology (championed principle of uniformitarianism).
 Jean Baptiste de Lamarck (1744-1829), Lamarckian evolution: adaptation, gradual change,
principle of use and disuse, inheritance of acquired characteristics
II. CHARLES DARWIN (1809-1882)
1831-1836: Voyage on HMS The Beagle
1858: An essay on ‘natural selection” presented at the meeting of the Linnaean Society of London
along with a manuscript by Alfred Russel Wallace (1823-1913).
1859: the publication of the first edition of “On The Origin of Species by Means of Natural Selection,
or the Preservation of Favoured Races in the Struggle for Life’.
Four principal postulates of the theory are:
1. The non-constancy of species: The world is not static but is evolving; living things, as
reflected in the fossil record, change over time.
2. Gradualism: Process of evolution is gradual and continuous.
3. The notion of branching (in contrast to the linearity of Scala Naturae): Similar
organisms, where related, are descendants from common ancestors; all living
organisms might be traced to a single origin of life.
4. Mechanism of Evolution: Evolutionary change is the result of selection, a two step
process: First step: production of variation. Second step: Selection through survival in
the struggle for existence.
Darwinian evidence for evolution: artificial selection, embryology, comparative anatomy, fossils.
Major influences came from
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II. AFTER DARWIN
Early 1900’s: Genetics, The science which plugs a hole in Darwin’s arguments.
1930’s and 40’s: Dobzhansky, Huxley, Rensch, Simpson, Mayr and Stebbins): Neo-Darwinism,
the “new synthesis” or Synthetic Theory of evolution.
The impact of Evolution:
o “There are no living sciences, human attitudes or institutional powers that remain unaffected
by the ideas that were catalytically released by Darwin’s work” (Collins 1959).
o “no biologist has been responsible for more-and for more drastic-modifications of the average
person’s worldview than Charles Darwin” (Mayr 2000).
Evolution: the organizing principle of biology.
Riyad A. Sadek, April 3, 2006
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o “Nothing in Biology makes sense except in the light of evolution.” (Dobzhansky 1973)
Human Evolution: biological and cultural evolution.
Evolution and ethics: Altruism in animal behavior, (kin selection and group selection).
Modern (Darwinian) Zeitgeist (Mayr 2000)
a) Rejecting all supernatural phenomena and causation.
b) Refuting typology with its emphasis on invariance and stability.
c) Refuting teleology: Nothing is predetermined
d) Refuting determinism; accepting the universality of randomness.
e) A new view of humanity.
i. Anthropocentrism not reduced but enhanced (Man is indeed unique)
ii. Providing a scientific foundation for ethics. (enhancing group survival if
behaving in a cooperative and altruistic manner)
Darwinian and Neo-Darwinian Evolution: Hypotheses and deductions
(Adapted from Moore 1984)
The title of Darwin’s book contained a statement of his theory. It is possible to formulate a
series of hypotheses that could be tested.
A. If the theory of evolution by natural selection is true, then:
 there must be variation among organisms,
 more offspring are born than survive,
 there are differences between offspring that survive and reproduce and those which do not,
 only those variations that are inherited are important.
B. If the theory of evolution is true, then:
 we must be able to obtain information on organisms that lived in the past,
 species that lived in the past must be different from the species alive today,
 the older the sedimentary strata, the less chance of finding fossils of contemporary species,
 we expect only the simplest organisms in the very oldest fossils and more complex ones appear
in more recent fossils.
 it must be possible to demonstrate the slow change of one species into another.
 there should be connecting forms between the major groups if we are to regard that all of
today’s species are descendants of a few original forms,
 the age of the earth must be very great, possibly many millions or billions of years old.
C. If the members of a group, such as the chordates, share a common ancestry, then:
 that should be reflected in their structure.
 that should be reflected in their embryonic development.
D. If there is a unity of life based on descent from a common ancestor then:
 that should be reflected in the structure of cells.
 that should be reflected in the molecular processes of organisms.
References/Suggested Readings
Collins, J, 1959 - Darwin’s impact on philosophy. Thought. 34:186-248.
Desmond, A. and J. Moore, 1992 – Darwin. Penguin Books, London.
Dobzhansky, 1973 -Nothing in biology makes sense except in the light of evolution. American
Biology Teacher 35:125-129.
Mayer, W.V. 1984 - The arrogance of ignorance: Ignoring the ubiquitous. American Zoologist
24:423-431.
Mayr, E. 2000 – Darwin’s Influence on Modern thought. Scientific American 283:79-83.
Moore, J.A. 1984 - Science as a way of knowing: Evolutionary biology. American Zoologist 24:467534.
Vuletic M.I. (Editor) – The Talk-Origins Archive: Exploring the evolution/creation controversy.
http://www.talkorigins.org/origins/faqs-index.html#index_d