V. Diversity

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V. Diversity
A. Age of Exploration (15th 17th Century)
1. Modern estimates 5-50 million species
2. Problems

• Not enough room on the Ark

• Extinction

• Organization?

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V. Diversity
B. Gods organizer Carl von Linne (Linnaeus)
(1707 1778)
1. System of Nature (1735)

• 4400 species of animals/ 7700 species of plants

• Binomial nomenclature

• Genus and species Pan paniscus

• Bonobos

• Homo sapiens

• Mammalia

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V. Diversity
B. Gods organizer Carl von Linne (Linnaeus)
(1707 1778)
2. Taxonomic categories

• Gorillas
• Chimps
• Orangutans

• controversy

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V. Diversity

• Linnaeus taxa only real in the mind of God

• Idealized forms

(type species)

• Darwin

• Evidence of common ancestry

• Works well with evolutionary
• scheme, not the Ladder of Life

• Nested hierarchies

family
genera

• Genetic connection

species

• DNA-DNA
• hybridization

• DNA profiling

3. Linnaeus remained creationist until late in
life
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V. Diversity
C. Richard Owen (1804 1892)
1. Archetypes (body plans)

• Homology same structures modified for
  different purposes

2. Owen example of argument from design
3. Darwin evidence of common ancestry
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VI. Before Darwin
A. Non-evolutionary thought
1. The Greeks

• Plato idealized forms are templates for
  imperfect
• replicas

• Aristotle

• Life is one big continuum

• Ladder of Life dominant until Darwin

2. The Bible

• All life created in one week, 4004 BC

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VI. Before Darwin
A. Non-evolutionary thought
3. Natural Theology

• As far back as Galen

• William Paley (1743 1805)

• Argument from design

• Revival in 19th Century

• Evolutions biggest competitor

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VI. Before Darwin
A. Non-evolutionary thought
3. Natural Theology

• Mid 18th Century (Enlightenment) looks for
  natural
• (materialistic) causes

• David Hume (1711 1776)

• Dialogues Concerning Natural Religion (1796)

• False analogy many ways in which living
• things are not like machines

• We dont know the nature of the designer(s)

• Much in the world that is imperfect and unjust

• Our knowledge of the Universe is limited

No testimony is sufficient to establish a
miracle, unless the testimony be of such a kind,
that its falsehood would be more miraculous than
the fact which it endeavors to establish.
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VI. Before Darwin
B. Evolutionary thoughts
1. Comte de Buffon (1707 1788)

• All species from family ancestors

• Species not real but rather varieties evolved
  from
• original form

• Ancestral forms from spontaneous generation

• First episode on primeval hot earth went extinct

• Second episode gave rise to ancestors of modern
  forms

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VI. Before Darwin
B. Evolutionary thoughts
2. Erasmus Darwin (1731 1802)

• Single common ancestor

• Competition

• Sexual selection

Organic life beneath the shoreless
wavesWas born and nurs'd in ocean's pearly
cavesFirst forms minute, unseen by spheric
glass,Move on the mud, or pierce the watery
massThese, as successive generations bloom,New
powers acquire and larger limbs assumeWhence
countless groups of vegetation spring,And
breathing realms of fin and feet and
wing. Temple of Nature (1802)
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VI. Before Darwin
B. Evolutionary thoughts
3. Jean-Baptiste Lamarck (1744 1829)

• Spontaneous generation starts
• the evolutionary process

• Progressive evolution with each generation
  becoming more complex

• Linear scale with humans the ultimate goal

• No gaps, only missing data

• No extinction (missing fossil not yet found)

• Process that distorts progression

• Inheritance of acquired characteristics

• Use and disuse of parts

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VI. Before Darwin
B. Evolutionary thoughts
4. Robert Chambers (1802 1871)

• Vestiges of Creation (1844)

• Progressive evolution

• Embryo occasionally jumps to another form

• Popular with the middle classes

• Not popular with conservatives or scientists

• Legacy

• Evolution equated with progress (popular idea)

• Starts debates over evolution

• Uproar over Vestiges makes Darwin cautious

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VII. Charles Darwin (1809 -1882)
A. Life
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VII. Charles Darwin (1809 -1882)
B. Voyage of the Beagle (1831 -1836)
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B. Voyage of the Beagle (1831 -1836)
1. Observations in South America and Australia
Greater Rhea
Lesser Rhea

• marsupials

Sloths
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B. Voyage of the Beagle (1831 -1836)
2. Observations in the Galapagos Islands
animals and plants of a region are most closely
related to those of nearby regions and reflect
the history of the region
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C. The Discovery of Natural Selection
1. Evidence from travels
2. Barnacles
3. Artificial Selection
4. Malthus (1766 - 1834)

• Population growth will always
• outpace food production

• Exponential vs. geometric

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C. The Discovery of Natural Selection
5. Darwins eureka moment (July 1837)
it was like admitting murder
6. The long interlude (20 years!)

• Other commitments

• Confidence

• Illness

• Concern

7. Letter from Alfred Russell Wallace (1823
1913)

• 1858

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D. On the Origin of Species (1859)
1. Contents and evidence

• Artificial selection

Zea mays

• Teosinte

maize
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D. On the Origin of Species (1859)
1. Evidence

• Taxonomy common ancestry

Neanderthals

• Fossil record

Archaeopteryx
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Biogeography
animals and plants of a region are most closely
related to those of nearby regions and reflect
the history of the region
Cactus
Spurge
Convergent evolution
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Homology

• Comparative anatomy

• analogy

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Homology
Embryonic development

• structure and pathways

• Pharyngeal pouches

Gills
Eustachian tubes
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Imperfections
Dandelion

• Vestigial structures

Pollen
Wisdom teeth
Goosebumps
Wings of flightless birds
Appendix
Whale pelvis
Cravings sugar and fat
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Imperfections
Evolution is a tinkerer.
Our textbooks like to illustrate evolution with
examples of optimal design ,,,. But ideal design
is a lousy argument for Evolution ,,,. Odd
arrangements and funny solutions are the proof of
evolution--paths that a sensible god would never
tread but that a natural process, constrained by
history, follows perforce.  
--Stephen
Jay Gould
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2. Challenges to the Theory
Time
Variation
The fossil record
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Fossil record

• Fish to amphibian

• Ape to human

• Whale evolution

• Bird evolution

• Caveat!

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3. Natural Selection
Theory a well documented, explanatory principle

1. All populations have the potential to overproduce

2. Because of limited resources, no population
increases indefinitely
3. Therefore, individuals must compete for
limited resources
4. Individuals with variations that allow them to
compete successfully for resources will
survive and reproduce at a higher frequency
5. If variations (4) are heritable, individuals
with those variations will exist at a higher
frequency in future generations
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3. Natural Selection
Differential reproductive success
survival of the fittest
Descent with modification
Bonobos
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4. The Fact and the Theory of Evolution
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5. The Uniqueness of Darwins Theory
No direction
Adaptation to local environments
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5. The Uniqueness of Darwins Theory
Population thinking
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5. The Uniqueness of Darwins Theory
Common ancestry
There is grandeur in this view of life, with its
several powers, having been originally breathed
into a few forms or into one and that, whilst
this planet has gone cycling on according to the
fixed law of gravity, from so simple a beginning
endless forms most beautiful and most wonderful
have been, and are being, evolved. Charles
Darwin, 1859.
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6. The Reaction to Darwins Theory

• Evolution

• Natural Selection

• Problems

• No mechanism to
• create diversity

• No progress

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7. Evolution the Organizing Principle of Biology
Evolution explains why organisms are similar
(common ancestry) and why they are different
(adaptation).