Evolution Before Darwin
Taxonomy - Biological Classification
• First invented in 1700’s by Carolus Linneaus for
cataloguing plant and animal species.
• Based on overall anatomical similarity.
• Similarity due to the “blueprint” of Creation.
'Deus creavit,
Linnaeus disposuit!
Most biologists of the 18th and early
19th Centuries were concerned with
describing and classifying species.
The question of species origins was
not an issue.
Pre-Darwinian Evolutionary Theorists
Jean-Baptiste Pierre Antoine de
Monet, Chevalier de la Marck
“Lamarck”
(1744-1829)
Erasmus Darwin
(1731-1802)
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Erasmus Darwin (1731-1802)
Physician, philosopher,
inventor, and poet.
• Charles Darwin’s grandfather.
• Founding member of the “Lunar Society” association of natural philosophers and industrialists.
• Published several works expounding an evolutionary
view of life, including “Zoonomia”, “The Botanic
Garden”, and “The Temple of Nature”.
• Erasmus D. postulated that living things changed
over time seeking greater perfection in a
progression from microorganisms to Man.
• Erasmus Darwin anticipated many
lines of evidence for evolution
later discussed by his grandson.
• He noted examples of how animals and
plants could be changed by
metamorphosis, climate, and selective
breeding.
• Vestigial organs were remnants of
earlier states - evidence of change.
• Mechanisms driving change included
self-directed change similar to that later
proposed by Lamarck.
Erasmus Darwin used America as an example of a continent that
was younger and “less evolved” than Europe, Asia, and Africa
“This idea of the gradual formation and
improvement of the animal world accords with
the observations of some modern philosophers,
who have supposed that the continent of America
has been raised out of the ocean at a later period
of time than the other three quarters of the globe,
which they deduce from the greater comparative
heights of its mountains, and the consequent
greater coldness of its respective climates, and
from the less size and strength of its animals, as
the tygers and allegators compared with those of
Asia and Africa. And lastly, from the less
progress in the improvements of the mind of its
inhabitants in respect to voluntary exertions.”
Thomas Jefferson collected the bones of large animals found in
Virginia and Kentucky, such as the American Mastodon, because
he wanted to show that American animals were just as impressive
as old world animals.
Jefferson rejected both
evolution and the idea
of American degeneracy
American Mastodon
Lamarck was a naturalist who started
out believing that species were fixed
but changed his mind after studying
fossil mollusks around Paris.
• He believed that microorganisms were
constantly coming into being through
spontaneous generation.
Lamarck
(1744-1829)
• All organisms had a tendency toward
progress, moving up a ladder of
complexity or ‘chain of being’.
• First to develop a coherent materialistic
theory of evolution that attempted to
explain how organisms changed and how
they become adapted.
Lamarck postulated two natural forces driving
evolution:
• The Complexifying Force - driving organisms up the
chain of being.
• The Adaptive Force - driving the adaptation of
organisms to their environments
- Organisms respond to their environment through the
use and disuse of features and organs.
- Use of an organ causes it to strengthen and develop.
- Disuse of an organ causes it to atrophy.
- Changes caused by use and disuse are
passed on to offspring - ‘Inheritance of
Acquired Characters’.
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• Lamarck and Erasmus Darwin attempted to find
materialistic (non-supernatural) explanations for the
origin of species and adaptation.
• However, “complexifying” forces and “self-directed
change” were not much more testable than
supernatural explanations and did not induce many
people to question creationism.
"(Lamarck provided)
the eminent service
of arousing attention
to the probability of
all change in the
organic... world,
being the result of
law, not miraculous
interposition".
By the 1830’s biology remained the only major branch
of science still rooted in a supernatural foundation.
As Darwin began his career, evolution was considered a fringe idea among
biologists and natural historians. Darwin himself found the creationist
explanations of William Paley to be very convincing.
“The logic of [Paley] and, as I may
add, of his 'Natural Theology,' gave
me as much delight as did Euclid.