Famous Bad Decisions
1886 -Sors Hariezon
1933-Joe Shuster & Jerry Siegel
1955-Sam Phillips
1862 - Ambrose Burnside
1876 - George Custer
1929 – Trofim Lysenko
• Head of Soviet
Ministry of Agriculture
• Strong advocate of
Lamarckian Evolution
(acquired
characteristics)
• Attempted to
vernalize wheat by
freezing prior to
germination
Differential Reproduction
• The driving force
behind evolution
• Populations shift
because not all
members of the
population have the
same fitness
• Nature provides
selective pressures
that determine who
reproduces most
Selective Pressure
• Nature “selects”
for various
phenotypes
based upon
whether or not
the features of
the organism
increase its
differential
reproduction
Modes of Natural Selection
• Stabilizing: Favors
average phenotypes
• Directional: one
phenotypic extreme
favored
• Disruptive: Both
extreme phenotypes
are favored
Directional Selection & Industrial Melanism
(Kettlewell Moth Experiment)
Transitioning Phenotypes
Stabilizing Selection
Stabilizing Selection
Disruptive Selection
Disruptive Selection
Endler’s Trinidadian Guppy
Analysis
Trinidadian Guppy Analysis
• Purpose: To see how the selective
pressures of coloration and predation
affect the phenotypic distribution in a
population
• Hypotheses to Be Tested:
– Bright coloration leads to preferential mating,
causing the population to shift towards bright.
– Bright coloration leads to increased predation,
leading to a phenotypic shift towards drab
Procedure
• To access simulation, google “Sex and the
Single Guppy”
• There are nine (9) combinations of
predator and prey to test.
• Each simulation should be run for 100
weeks. Stop manually at this point
• BEFORE looking at analysis of results,
record the phenotypic results, pop. size
and # of Generations