Before Darwin

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Before Darwin

• Historical Examples show the
• Evolution of Evolutionary Theory

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Figured Stones

• For centuries, people had noticed images of
  plants and animal remains in stones and wondered
  at them.
• In China, people sometimes found dragon bones
  (fossils bones of ancient animals) which were
  used to make medicine.
• Tongue stones (fossil sharks teeth) were known
  in Italy as curiosities.

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Fossil

• The term fossil in 16th and 17th century Europe
  referred to just about anything dug from the
  earth crystals, interesting mineral concretions,
  metal ores, and the figured stones that today
  are called fossils.

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Early European theories

• The rise of the Enlightenment brought new ideas
  about figured stones
• Did they grow from seeds or eggs trapped in
  rocks?
• Were they remains of victims of the Biblical
  flood?
• Were they organic at all?

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Steno (Niels Stensen, 1638-1686)

• Danish anatomist, studied medicine in the
  Netherlands and France.
• Came to Florence at the request of the Duke of
  Tuscany to run a hospital and continue his
  research.

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Steno and the Shark

• 1666 Fishermen in Livorno, Italy, caught a giant
  shark. The local duke had it shipped to Steno for
  study.
• Steno noticed similarities between the sharks
  teeth and tongue stones that were well known at
  the time.

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Corpuscle Theory of Matter

• Steno used the Corpuscle Theory of Matter to
  explain the transformation of sharks teeth into
  tongue stones.
• Naturalists of the day hypothesized that matter
  was made of corpuscles (essentially molecules).
  Steno suggested that the corpuscles of the teeth
  had been gradually replaced by corpuscles of
  stone as the teeth sat in the rocks.

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Thinking Challenge

• What was so radically different about Stenos
  corpuscular hypothesis about tongue stones?

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Johann Beringer (d. 1740)

• Dr. Johann Bartholomew Adam Beringer, professor
  of Medicine in Würtzburg, lectured widely on
  fossils.
• In 1726, Beringer published Lithographia
  Wirceburgensis, a catalog of fossils he and his
  assistants had unearthed near his home.

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The Figured Stones of Würtzburg
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More stones

• Some figured stones even bore Hebrew letters,
  spelling out the name of God.
• Beringer took these as possible signs that the
  stones were the work of the Creator, but also
  suggested they could be sports of nature formed
  by the plastic power of the earth, or that some
  that resembled living things might grow from
  trapped seeds or eggs.

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Thinking Challenge

• Beringer may have been wrong in the end, but he
  was doing something right. What was it?

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Georges-Louis LeClerk, Compte de Buffon
1707-1788

• Life work Buffon believed that naturalists
  should search for a natural taxonomy, find the
  order in nature.
• Asked by the King to catalog the Royal Garden
  collection, Buffon decided to catalog everything
  in nature.
• Wrote 36 volume Histoire naturelle, générale et
  particulière.

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Thinking Challenge

• In Buffons time, nothing was known about genes
  and heredity. Does modern genetic knowledge
  support or refute his theory? Explain as best you
  can.

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Georges Cuvier 1769-1832

• Supported the static model of species species
  do not change because they cannot survive
  changes.
• Comparative anatomist looking for patterns in
  structure, especially among vertebrate animals.
• Set up a natural, non-hierarchical taxonomy of
  animals based on the nervous system.

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Cuviers Principles

• Correlation of parts An organism is a functional
  unit with all part integrated. Each organism is
  adapted to its niche. Single parts can give clues
  about the entire organism.
• Morphological type concept Every taxon (group
  of organisms) can be defined sharply and is
  stable.
• Explained changes in the fossil record as
  evidence of Catastrophism.

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Thinking Challenge

• Think about Cuviers point if an organism is
  well-adapted to its environment, there is no
  reason for it to change. Does this fit or not fit
  with modern evolutionary theory? Explain.

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Jean-Baptiste Pierre Antoine de Monet de Lamarck
1744-1829

• Protegé of Buffon. Interested in natural
  classification of living organisms.
• Background was in Botany, but later studied
  invertebrates.
• Primary questions Where do you draw the line
  between species? How do you rank species?
• Favored a theory of inheritance of acquired
  characteristics.

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Lamarcks Organic Law of Development

• Spontaneous Generation creates new, simple
  organisms, such as bacteria.

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Lamarcks Organic Law of Development

• Organisms are shaped by their environment.

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Lamarcks Organic Law of Development

• Change is teleological (goal-directed). Organisms
  have an internal drive to become more complex.

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Lamarcks Organic Law of Development

• Use and disuse of parts causes change that is
  passed on to the next generation.

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Thinking Challenge

• Consider this statement Fruit flies exposed to
  pesticides slowly get used to the pesticides and
  are no longer killed by it. Each generation
  becomes more and more resistant.
• Does this statement fit Lamarcks ideas or modern
  ideas about evolution? Explain.

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The Difficulties

• While the theories of Lamarck and Buffon made
  sense in terms of logic, the evidence to support
  them was slight and they were not widely
  accepted.
• Heredity was not understood. No one knew about
  genes or chromosomes, and even the nucleus of the
  cell had not been discovered.
• Until a hereditary mechanism was discovered,
  there was little that could be done to evaluate
  these theories.