Studying Nature
Which of the following 6 statements are
NOT testable by the scientific method?
1.
2.
3.
4.
5.
6.
Increasing numbers of deformities such as the extra limbs that
have been noted in many frog populations in North America
are caused by infection by trematodes (parasitic flatworms).
People with strong religious beliefs live more meaningful lives.
People are more likely to survive cancer if they have a positive
attitude.
Humans and chimpanzees diverged from a common ancestor
that lived 5 – 7 million years ago.
Corn seedlings grow more quickly when people talk to them.
If you live a good life, you will be rewarded with an eternity in
Heaven.
Fill in the blank:
• Recorded observations are called ________
• Data
• Through _____________ reasoning scientists derive
generalizations based upon a large number of specific
observations. Through _____________ reasoning logic flows
from the general to the specific.
• Inductive
• Deductive
• A _______________ is a tentative answer to a well-framed
question.
• Hypothesis
• No amount of experimental testing can _________ a
hypothesis, because it is impossible to test _____ experiments
to falsify them.
• Prove
• All
Scientific Method in Action –
Mimicry in Snakes
Title: The effect of coloration (mimicry) of snake on predator attacks.
Hypothesis: If the king snake lives in the same region as a coral snake,
then predators will not attack the king snake because mimicry will protect
the king snake.
IV: Coloring of Snake (mimicry)
Brown Coloring (control)
Red, black & white ring (experimental
group)
DV: predator strikes/attacks
Constants: both types of coloring found in all test areas, same size artificial
snake, same length of time, same number of snakes of each color in all test
areas, artificial snakes made of the same material, both types present during
the same season
Lab Report / Poster Expectations…
•
•
•
•
Title – link IV to DV
Introduction – Background with Hypothesis
Materials and Methods
Results – discuss variables (experimental design), data table,
graphs, data analysis
• Conclusion
• Literature Cited
• See Handout for details
Compare and Contrast
Theory
• Broader in scope
• General enough to
generate many
hypotheses that can be
tested
• Supported by a massive
body of evidence
• May need to be modified
or refuted based upon
new information
Hypothesis
• Narrow focus
• Very specific question is
being asked/tested
• Supported or disproved
by a few experiments
Review – choose one of the testable
hypotheses from this list and explain how you
would test it (record your response in your
journal.)
1. Increasing numbers of deformities such as the extra
limbs that have been noted in many frog populations
in North America are caused by infection by
trematodes (parasitic flatworms).
2. Humans and chimpanzees diverged from a common
ancestor that lived 5 – 7 million years ago.
3. Corn seedlings grow more quickly when people talk
to them.
Evidence that theories change
• Five-kingdom theory of biological diversity was proposed in
1968.
• Five-kingdoms replaced Linnaeus’s original two-kingdom
system
• Now we are moving to a three-domain system with at least
five-kingdoms (maybe more in the future?)
• Why are we moving to 3 domains??
• Increased information from careful comparison of structure and
function (i.e. DNA comparisons)
Is all “real” science hypothesisdriven and experimental?
Discovery (Inquiry) Science
Modeling
NO!
• Homework:
• Collect pill bugs or stink bugs over the
weekend so we can do an experiment
on Tuesday.
• Read and summarize chapter 2 for 9/5
• Read and summarize chapter 3 for 9/6
• Clicker Review time!