Transcript Saving the Best for Last - Illinois Valley Community College

Teaching Evolution and
Natural Selection
by
Answering Questions First and
Placing Conclusions in Scientific Context
Mike Phillips
Geology Professor
Illinois Valley Community College
Why Do Myths &
Misrepresentations Persist?
It is often easier to reject the
seemingly complex science rather
than accommodate the conclusions.
 conflict with personal philosophy
 misunderstanding of the science
 disagreement with the implications
 the perceived cost of acceptance
outweighs and understood benefits
Barriers to New Ideas
“…information consistent with a
preferred conclusion is examined
less critically than information
inconsistent with a preferred
conclusion, and consequently, less
information is required to reach the
former than the latter.”
Ditto & Lopez, 1992, Motivated Skepticism: Use of Differential
Decision Criteria for Preferred and Nonpreferred Conclusions,
Journal of Personality and Social Psychology, Vol. 63, No. 4, 568584
Barriers to New Ideas
“…across age groups, scientific reasoning
was used to reject evidence that
contradicted prior beliefs; relatively
cursory reasoning was used to accept
belief-consistent evidence.
“Biased reasoning was more common
among middle-aged and older adults than
among young adults.”
Klaczynski & Robinson, 2000, Personal Theories, Intellectual Ability, and
Epistemological Beliefs: Adult Age Differences in Everyday Reasoning
Biases, Psychology and Aging, Vol. 15, No. 3. 400-416
Barriers to New Ideas
“…for incongruent evidence…Cognitive
vigilance and accuracy motivation increase,
evidence representations are focused on
logical coherence, and sophisticated
reasoning abilities are activated.
“A search for that reasoning strategy most likely
to yield satisfactory results (i.e., rejection of
the unfavorable evidence) then ensues. If no
such strategy is found, processing reverts
back…and developmentally primitive
strategies are used to reject the evidence.”
Klaczynski & Robinson, 2000
Barriers to New Ideas
“…when confronted with an incompatible
argument to evaluate, people will engage
in a deliberative search of memory in an
attempt to retrieve material for use in
refuting the position advocated.
“Because most of the retrieved material will
be refutational in nature, there will be a
bias to judge the argument as weak.”
Edwards & Smith, 1996, A Disconfirmation Bias in the Evaluation of
Arguments, Journal of Personality and Social Psychology, Vol. 71, No. 1,
p.5-2
Barriers to New Ideas
“…ideological subgroups failed to
update their beliefs when presented
with corrective information that runs
counter to their predispositions.
Indeed, in several
cases…corrections actually
strengthened misperceptions among
the most strongly committed
subjects.”
Nyhan & Reifler, 2010, When Corrections Fail: The Persistence of
Political Misperceptions, Political Behavior, Vol. 32, No. 2, p. 303330
Implications for Presenting
New Ideas

The brain will do its best to defend
against new ideas that are
incompatible with firmly held beliefs.

When conclusions are presented
first, as a structural frame to provide
context for the data, personal bias
may cause a rejection of subsequent
supporting information.
Is There Any Hope?
“There is considerable evidence that
people are more likely to arrive at
conclusions that they want to arrive
at, but their ability to do so is
constrained by their ability to
construct seemingly reasonable
justifications for these conclusions.”
Kunda, 1990, The Case for Motivated Reasoning, Psychological
Bulletin, Vol. 108, No. 3, 480-498
Hope…
“…when confronted with a compatible
argument, people will allocate fewer
processing resources to its scrutiny
and will be more inclined to accept
the argument at face value or judge it
to be strong, or both.”
Edwards & Smith, 1996
Hope…
“If evidence is theory congruent…
Cognitive vigilance, accuracy
motivation, and efforts to prevent
memory interference are low; the
data are assimilated into theory; and
arguments for evidence acceptance
are often superficial.”
Klaczynski & Robinson, 2000
Hope…
“For analytically oriented individuals,
the outcome of reviewing theoryrelevant evidence depends on the
quality of the evidence and may lead
to theory maintenance or theory
revision.”
Klaczynski & Robinson, 2000
What to Do?

Avoid triggering
 Disconfirmation
 Backfire
effect
bias
What to Do?
Identify firmly held beliefs & triggers
 Present congruent information as a
foundation
 Frame arguments as compatible with
beliefs

Application
Collect Questions
 Provide Historical Context
 Present Core Evidence

 focus

on the congruent & compatible
Build up to the Conclusion
Collect Questions
Identify the audience
 People saving questions

 Have
trouble focusing
 Might maintain a hostile mood

Discuss myths and misperceptions
 Audience
can begin to discard
 Not “straw men”
Collect Questions
Provide cards to arriving audience
 Prompt for positive & negative
questions
 Sort quickly and respond to some
 Use the remainder to frame the
presentation


Set a positive, respectful tone
Dealing With The Cards
Use outline to sort
 Build a history

 Develop
categories
 Sort quickly
 Identify key concepts

The first time is the worst
Dealing With The Cards

Cards/questions – common
responses
 monkey-human relationship
 variety of religious views
 naturalism
 “the
strongest survive”
Provide Historical Context
People respond to stories
 People relate to struggle
 Provides a frame of reference
 Presents many myths &
misperceptions as valid but out-ofdate
 Scientists are protagonists

Provide Historical Context
Tell the story
 Describe the original understanding
 Set up the problem(s)
 Stop at key waypoints
 Highlight evidence that was
surprising at the time
 Build up to the conclusion

Present First Evidence First
Models good science
 Builds the historical chain
 The early evidence convinced the
early skeptics


Presenting conclusions first
 appears to be a priori
 triggers cognitive barriers
 removes context
Example Unit Structure
Historical Geology
 Collect Questions
 Story of Darwin as a Frame
 The Evidence - “Origin” as a guide

 for
evolution: rocks, fossils, anatomy,
genetics
 for natural selection: selective breading,
natural conditions, mutations,
populations
Historical Geology Intro
Reading the rocks
 Reading the fossils
 Interpreting rock forming
environments
 Relative dating
 Absolute dating
 History of the Earth
 Cladistic relationships of fossils

Evolution & Natural
Selection Unit
Collect Students’ Questions
 Story of Darwin & Development of
Theory

 Darwin’s
education
 Voyage of the Beagle
 collection
of fossils & live organisms
 observation of global & temporal diversity
 Collection
of more data
 Publication of Origin
Evidence for Evolution
Rock Record
 Fossil Record
 Geographic Distribution of Life
 Anatomy & Physiology
 Genetics
 Cladistic Analysis

Organic Evolution: Conclusions

the characteristics of populations of living
organisms have changed through time
 life
has become more complex
 life has become more diverse
 all life is related
 this is accepted as a factual observation

the interpretation of the relationships
between organisms is being expanded &
refined
Missing links!!!

the “link” between two fossil species OR
between a fossil species and a living species

PRESERVATION AS A FOSSIL IS RARE!
many “links” found (it’s just a matter of time and effort)
 however: each “gap” filled creates two new
“gaps”

Question

What is the mechanism that resulted
in the evolution of life?
Evidence for Natural Selection
populations of organisms display a
variety of characteristics
 genetics
 artificial selection – domestic plants
& animals
 natural selection

 environmental
stresses & opportunities
 isolation of populations
Conclusion

The variety of conditions in the
natural environment results in
natural selection of populations
which, in turn, is responsible for
biological evolution.
Randomness
mutations are random
 evolution is not random
 natural selection is not random


favorable mutations survive through
reproduction
Interesting Details
Divergence & Speciation
 Extinction
 Convergence
 Homology & Vestigial Organs
 Coevolution & Symbiogenisis
 Phyletic Gradualism &
Punctuated Equilibrium
 How did it start?
 Evolution has no end
 Nothing is too complex to investigate.

Key Points
Identify firmly held beliefs & triggers
 Present congruent information as a
foundation
 Frame arguments as compatible with
beliefs

Thank You!
Mike Phillips
Illinois Valley Community College
[email protected]
http://www.ivcc.edu/phillips