Transcript The Evolution Revolution

The Evolution Revolution
Charles Darwin and the Rise of
Modern Science
Early 19th Century
• Science on the rise
• Structure of the physical universe better
understood.
• Biology poorly understood
Big Question
• What is the origin of species?
• Divine Creation: God created all living
things as they are and they do not change
over time. (prevailing view)
Evolution
• A radical idea that gains support in the 18th
Century.
• Geologist find evidence for an old and
changing Earth.
– Mountain building and erosion patterns.
– Fossils in strange places and strange fossils.
Lamarck’s Concept of
Evolution
Jean-Baptiste Lamarck
(1744-1829)
• Made many important
contributions to biology
(Medicine, Botany, Invertebrate
Zoology).
• One of the first scientist to
become convinced evolution
happens.
Lamarck’s Concept of
Evolution
• Environmental changes occur.
• Changed environment alters the needs of living
things.
• These altered needs lead to changes in behavior.
• Altered behavior means that some structures/organs
will have more or less use.
→
Okapi
Evolution of
the Giraffe
↓
The Life of Darwin
(1809-1882)
• Washes out of Medical
School.
• Completes Bachelor’s
Degree and is preparing
to enter clergy.
• Much more interested in
being a “naturalist”.
• Receives offer to sail on
the HMS Beagle
Voyage of the Beagle
(1831-36)
Mission: To Map the
Coastline of S. America
Capt. Robert Fitzroy
Darwin’s Landing at Buccaneer Cove, Santiago Island
“Nothing could be less inviting than the first appearance.”
--Charles Darwin
High Number of Endemics
• Most species are endemic (i.e. found
only on the Galapagos).
– 42% of the plants
– 100% of the land reptiles
– 26% of sea birds
– 75% of land birds
– 82% of mammals
Land Iguana (South Plaza Island)
Galapagos Tortoise (Geochelone elephantopus)
Scientific Method
• Set of rules used to study natural phenomena.
• These rules are used in an effort to focus
research in the most useful direction.
• They also (hopefully) keep us from jumping to
appealing but erroneous conclusions.
Scientific Method
Observations
Hypothesis
Experimentation
Hypothesis revision
New Experiments
Theories and Models
Scientific Method
1.
2.
3.
4.
Scientist use this method to avoid:
Reliance on authority or revealed
wisdom.
Over use of “common sense”.
Acceptance of anecdotal data.
Accepting an hypothesis with
inadequate testing.
Darwin’s Scientific Method
• Massive Observations
– Selective breeding
– Observations of other scientists
– Beagle observations
• Development of a Hypothesis
– Evolution: Change over time
– Natural Selection as the Mechanism
Development of a Theory
• Theory: A hypothesis that has been
thoroughly tested and never falsified.
• Accepted to be true and used as a basis
for future hypotheses
– e.g. Einstein’s theory of Relativity.
The Theory of Evolution
• Change over time: Thoroughly
documented and demonstrated
– anatomical evidence
– fossil evidence
– development
– molecular evidence
• Natural Selection: Shown to be the major
way in which this change occurs. (but not
the only way)
The Controversy
• Copernicus, Galileo, Newton, and Kepler
changed the way we view the functioning
of our world.
– Earth is not the center of the universe
• Darwin changed the way we view creation
(life) itself.
– Humans are not the center of the Earth
New View of Life
(the Moran version)
• Humans are part of a long (billions of
years) and fascinating history of life.
• All life is unique and special
• We are creations of this world but the
world was not created for us.
Slow to publish: Why so long?
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Anguish
Illness
Slow development of ideas
Collection of a wealth of evidence
Anguish
• Social class
– Respectability
– Evolution subversive - against his class
• Religous considerations
– especially worried about hurting wife Emma
who grieved for his soul
• Scientific prejudice against “speculation”
• “Like confessing a murder.”
Illness
• Sea sickness
• Problems throughout life
– violent shivering, vomiting, exhaustion,
palpitations, hands trembling, head
swimming, sleeplessness, headaches,
flatulance, stomach problems, ringing of ears,
fainting, copious palid urine
• In 1841 could work “an hour or two a
couple of days a week.”
• Chaga’s disease or just nervous?
Slow to publish: Why so long?
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Anguish
Illness
Slow development of ideas
Detailed analysis, collection of a wealth of
evidence
– pigeons
– barnacles
Alfred Russel Wallace
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Thought of natural selection (1959)
Wrote to Darwin
Darwin had been working on book
Published a “letter” jointly
Wallace didn’t
– put in the hard yards collecting and
documenting evidence to support theory
– remain in favour of the theory
• Darwin did!