Transcript Chapter 18: Darwin and Evolution

Chapter 22: Darwin and
Evolution
• Evolution refers to the processes that
have transformed life on earth from its
earliest forms to the enormous diversity
that characterizes it today.
• Charles Darwin published On the Origin
of Species by Means of Natural Selection
on November 24, 1859. It was the first
convincing case for evolution.
Chapter 22: Darwin and
Evolution
• Darwin made two major points:
1. Species evolved from ancestral species and were
not specially created.
2. Natural selection is a mechanism that could
result in this evolutionary change.
Chapter 22: Darwin and
Evolution
I. A Historical Context for Evolutionary Theory.
A. Western culture resisted evolutionary views of life.
– The Scale of Nature and Natural Theology
– Cuvier, fossils, and catastrophism
Chapter 22: Darwin and
Evolution
I. Historical Context for Evolutionary Theory.
B. Theories of geological gradualism helped clear the
for evolutionary biologists.
– James Hutton:Gradualism
– Charles Lyell: Uniformitarianism
path
Chapter 22: Darwin and
Evolution
I. Historical Context for Evolutionary Theory.
C. Lamarck placed fossils in an evolutionary context.
– Use and disuse
– Inheritance of acquired characteristics
Chapter 22: Darwin and
Evolution
II. The Darwinian Revolution
A. Field research helped Darwin frame
his view of life.
– The Voyage of the Beagle
– Darwin focuses on adaptation
Chapter 22: Darwin and
Evolution
II. The Darwinian Revolution
B. The Origin of Species developed two main points: the
occurrence of evolution and natural selection as its
mechanism.
– Descent with modification
– Natural selection and adaptation
Chapter 22: Darwin and
Evolution
III. Evidence of Evolution
A. Evidence of evolution pervades biology.
– Biogeography-The geographical distribution of species.
– Fossil Record-It is incomplete but shows general trends in
evolution.
Distribution on moonjellyfish
Chapter 22: Darwin and
Evolution
III. Evidence of Evolution
A. Evidence of evolution
pervades biology.
– Comparative Anatomy
• Homologous structures
• Analogous structures
• Vestigial structures
Chapter 22: Darwin and
Evolution
III. Evidence of Evolution
• Comparative Embryology
• Molecular Biology-DNA
Chapter 22: Darwin and
Evolution
III. Evidence of Evolution
A. What is theoretical about the Darwinian
view of life?