Studying Nature

Which of the following 6 statements are NOT testable by the scientific method?

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. People with strong religious beliefs live more meaningful lives.3. People are more likely to survive cancer if they have a positive

attitude.4. Humans and chimpanzees diverged from a common ancestor

that lived 5 – 7 million years ago.5. Corn seedlings grow more quickly when people talk to them.6. 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

IV: Coloring of Snake (mimicry)Brown Coloring (control) Red, black & white ring (experimental

group)DV: predator strikes/attacksConstants: 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

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.

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 hypothesis-driven 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!