I. Darwin

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I. Darwin

• A. Original ideas
• 1. Species are fixed/permanent
• 2. Earth is less than 10,000 years old
• and relatively unchanging

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B. Early Scientists

• Suggested Earth might be a lot older than a few
• thousand years by looking at specific
  fossils
• certain living animals were similar but not
  exactly
• alike

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• 180 million years ago, Pangaea split in 2 land
  masses
• India collided with Eurasia just 4050 million
  years ago, forming the Himalaya mountain range.
• The continents continue to drift today.

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B. Scientists

• Jean-Baptiste Lamarck (mid-1800s)
• a. Proposed that life evolves/changes
• b. Proposed that by using or not using a
• body part, an organism develops certain
  
• acquired characteristics- thought
  these
• could be passed on to offspring
• c. Inheritance of Acquired Characteristics

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Lamarcks Giraffe
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C. Charles Darwin

• Mission
• to study the geology, plants, animals he
  encountered
• on his voyage for 5 years
• Ship was the H.M.S. Beagle
• Focused on the Galapagos
• Islands

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• 4. Observations
• a. too many organisms are
• produced
• b. organisms vary
• c. organisms struggle to
• survive (fight for food,
• mate, habitat, etc.)
• d. the fittest for the environment survive
• e. the fittest get to reproduce and pass on
  their
• genetic traits

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C. Charles Darwin

• Main Points
• A. Descent with modification-
• organisms over long amount of time
• will accumulate different
• modifications to survive in
• environment
• B. Theory of Natural Selection
• individuals with inherited
  characteristics
• well-suited for their environment
  survive to leave
• more offspring on average than other
  individuals
• Survival of the fittest

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Descent with Modification
Survival of the fittest
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D. Alfred Wallace (1858)

• Came to same conclusion as Charles Darwin, sent
  Darwin his manuscript.
• Darwin published his book, On the Origin of
  Species, in 1859.
• Why didnt he publish sooner?

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Honey Badger
WHAT DOES IT MEAN THE FITTEST?
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Butterfly
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Sea Slug Glaucus atlanticus
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Nudibranchs
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Red Squirrel
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Dogs vs. Wolves
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Water Bears
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Venezuelan Pitcher Plant
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Hemeroplanes triptolemus moth
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Glasswing Butterfly
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Camel
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II. Evolution

• Define evolution
• gradual changes that have transformed
• life over an immense period of time

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A. Evidence of Evolution

• 1. Fossil record
• 2. Geographic Distribution- continental drift
• 3. Similarities in structures
• 4. Similarities in development
• 5. Molecular biology- DNA, proteins

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B. Fossil Record

• A fossil is preserved remains or markings left
• by organisms that lived in the past
• 2. Fossils are cast in sedimentary rock

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Imprint
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Mineralized
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Frozen
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Amber
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Cast
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C. Geographic Isolation

• Traits of organisms are directly linked to the
• geography and environmental conditions of
• an area

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D. Homologous Structures

1. Homologous Structures different organisms that
   have similar bone structure

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E. Analogous Structures

• 1. Define features of different species that
  are similar in
• function but not in structure- are not
  derived from a
• common ancestor, but evolved in response
  to similar
• environmental challenge.

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Examples
2. Example Insects and birds both have wings to
fly, although their wing structure is very
different structure. The fat-insulated,
streamline shapes of seals (mammals) and
of penguins (birds) is another example.
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F. Vestigial Structures

• 1. Vestigial Structures- remnants of structures
  that may have had important functions in an
  ancestral species but have no function currently

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G. Similarities in Development

• Embryos of closely related organisms
• have similar stages in development

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H. Molecular Biology

1. Similar DNA suggests an evolutionary relationship

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III. OTHER CONCEPTS IN EVOLUTION

• A. Antibiotic- and Pesticide-Resistance
• 1. Antibiotic- medicine that kills/slows
  the
• growth of bacteria
• 2. Some bacteria with natural resistance
  will
• not be killed off by the antibiotics
  and can
• re-grow a resistant population quickly

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• 3. When pesticides are used, some insects will
  already have a natural resistance and survive the
  spraying, then reproduce more insects that
  inherit the resistance genes. Eventually the
  same pesticides will not have the same effect as
  before.

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B. Artificial Selection

• 1. Define selective breeding
• of domesticated plants
• and animals to produce
• offspring with genetic
• traits that humans value

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IV. Types of Evolution

1. Divergent Evolution organisms that very similar
   evolve to become very different

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• Convergent evolution
• when unrelated organisms evolve similar
• adaptations because of similar environment

Ex sharks and dolphins share analogous body
plans, yet have different ancestral backgrounds
(fish versus mammal)