Evolution…day 1

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Evolutionday 1
Barbara McClintock
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Schedule

•  
• Feb 5     Natural Selection Evolution 
• Feb 7     Phylogenetics Major Transitions
• (assignment due Feb. 14 
• Phylogeny Problem and Topic selection for
  paper)
• Feb. 12   Documentary OR day off with an evening
  viewing of the documentary?? Schedule?
• Feb. 14   Origins of Life
• Feb. 19    Origins of Structure Adaptation
• Feb. 21    Origins of Species

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Great Ideas (Pyles!) Assignments

• Problem in Phylogenetics
• Instructions Thursday Feb. 7
• Can be completed individually or pairs (2 only
  per team)
• DUE Feb. 14th (happy valentines day)
• Paper on Evolution (individual)
• Instructions on Thursday Feb. 7
• Topics (your topic selection due Feb. 14)
• Homo sapiens X evidence of bad design?
• Evolution of the group X
• Evolution of the characterisic X
• Propose something (but no politics, please)
• DUE March 11

4

• When analyzing a scientific explanation, which of
  the following is most important?
• Logic
• Data
• Source (i.e., scientific standing of the author
  or institution)
• Hypothesis
• All of the above

5

• FREE FLOW .

6

• The best definition of the process of EVOLUTION
  is
• Survival of the fittest.
• Origin of new species from existing species.
• Different individuals leave behind different
  numbers of offspring.
• Selection of new traits in a species from
  environmental pressures.
• Humans descended from chimps in Africa.
• The Strong eventually eliminate the Weak.
• A steady march of progress from microbes to man.

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Natural Selection

• Some characteristics of individuals are heritable
• Some individuals will have higher survival rates
• Some individuals will have higher reproduction
  (more offspring higher fecundity)
• If heritable characteristics are linked to those
  individuals with higher fecundity
• THEN, the next generation will have more of
  those advantageous heritable characteristics
• Thus, differential reproduction of individuals
  with heritable characteristics will shift the
  genetic profile of the population, increasing
  those advantageous traits in the next
  generationand so on, and so on

8
Modern Synthesis Evolution

• Differential reproduction (aka natural
  selection) can shift the genetic profile of
  organisms over time.
• Are there any other phenomena that can also
  affect the genetic profile of a group of
  organisms over time?
• YES!

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Modern Synthesis Evolution

• Genetics
• Mutations
• Chromosomal changes
• Duplication of a gene or genes
• Incomplete reproductive isolation (hybrids)
• Population size or composition
• Immigration or loss of portions of original
  group
• Emigration from outside sources
• Nonrandom mating
• Historic Contingency
• Random events (e.g., huge meteors! disease!
  Fast climate change!, etc.)

10
Modern Synthesis Evolution

• Natural Selection
• Genetic mechanisms
• Population size or composition
• Nonrandom mating
• Historic Contingency

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Misconceptions

• HOW IT WORKS!
• Evolution is progressive
• Evolution is random
• Organisms try to adapt
• Natural selection gives organisms what they
  need
• Gaps in the fossil record disprove evolution
• Evolution cannot be observed or tested

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Scalae naturae (Aristotle)
13
Survivors

Origins Extinctions
Darwins concept of tree of life (1859)
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(No Transcript)
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TETRAPODA
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Which came first??

• Of the following pairs, which came first
  historically?
• FISH or AMPHIBIANS
• MOSS or FISH
• DINOSAURS or BIRDS
• BEES or FLOWERS
• EUKARYOTIC or PROKARYOTIC cells
• CELLS or VIRUSES

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Misconceptions

• HOW IT WORKS!
• Evolution is progressive
• Evolution is random
• Organisms try to adapt
• Natural selection gives organisms what they
  need
• Gaps in the fossil record disprove evolution
• Evolution cannot be observed or tested

18
Misconceptions

• Random?
• Sometimes yes
• Mutations and genetics jumps (e.g., gene
  duplication)
• Historic contingencies
• Sometimes no
• Natural selection is NOT random
• Nonrandom breeding is notwell, you know

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Misconceptions

• HOW IT WORKS!
• Evolution is progressive
• Evolution is random
• Organisms try to adapt
• Natural selection gives organisms what they
  need
• Gaps in the fossil record disprove evolution
• Evolution cannot be observed or tested

20
Misconceptions

• Organisms can think ahead
• NOPE!
• Giraffes cant get longer necks by stretching
• Giraffes with longer necks get more food and are
  able to reproduce more offspring
• They dont think their way there
• Nature can think ahead
• NOPE! Nature cant predict what will happen next
• METEOR!!RUN!
• And, oh by the wayscientists cant predict
  either!

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Misconceptions

• HOW IT WORKS!
• Evolution is progressive
• Evolution is random
• Organisms try to adapt
• Natural selection gives organisms what they
  need
• Gaps in the fossil record disprove evolution
• Evolution cannot be observed or tested

22
Gaps?
one gap
Shanks paradox named for the author
At least a little logic is a requirement for any
argument.
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Misconceptions

• HOW IT WORKS!
• Evolution is progressive
• Evolution is random
• Organisms try to adapt
• Natural selection gives organisms what they
  need
• Gaps in the fossil record disprove evolution
• Evolution cannot be observed or tested

24
Misconceptions

• Science is not restricted to controlled
  experiments.
• Astronomers cannot hold stars in their hands,
• Geologists cannot go back in time,
• Epidemiologists dont create epidemics to study
  them.
• But in all cases scientists can learn a great
  deal by using multiple lines of evidence to make
  valid and useful inferences about their objects
  of study.