While studying photographs of animals at her University’s library, a zoologist notices a striking...

Post on 16-Jan-2016

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While studying photographs of animals at her University’s library, a zoologist notices a striking difference between animals from Africa and animals from Asia.

African Wild Dog Asian Wild Dogvs.

Here’s what she sees:

African Elephant Asian Elephant

vs.

And this:

African Fox(Fennec Fox)

Asian Fox(Corsac Fox)

vs.

And this:

In nearly every comparison, the zoologist observes that the ears of African mammals are twice as large as than the ears of Asian mammals.

Quantitative, Qualitative, or inference?

Since all of the large-eared animals are African, the zoologist reasons that large ears must be an adaptation to life in Africa.

Quantitative, Qualitative, or inference?

African Serval African Kudu

The inference leads to a question: why do African animals have such large ears?

She comes up with several competing hypotheses, each of them equally possible.

Better hearing?

Look bigger (intimidate other

males?)

Attract females?

Keep away flies?

Stay cool in the heat?

Something else?

To narrow down the hypothesis, she does some background research. She learns that:

• African elephants have no natural predators.• Males intimidate with their tusks, not their ears.• The average temperature of the African savanna is 70°-113° F. • African elephants have no sweat glands.

Better hearing Intimidate The African savanna is extremely hot

X X

Now, she has a very specific hypothesis: the African elephant has large ears ears to stay cool.

If she is right, then the elephant’s ears should be the coolest part of its body.

She must now conduct an experiment to test her hypothesis.

Early attempts to test the hypothesis fail.

Eventually, she decides to use a heat-sensing video camera to see if the elephant’s ears are indeed cooler than the rest of its body.

Video Camera

Video from the experiment:

Hot

Cool

During the experiment, she collects quantitative data: the temperature of the ears is 88° F, 10-15 degrees cooler than the rest of the body.

Hot

Cool

Based on the data, she concludes that her hypothesis was supported.

Victorious, the zoologist reports her results in the University’s science journal, so that other researchers can repeat the experiment.

If the hypothesis is tested many times with different African animals, and if the hypothesis is always supported, the hypothesis will become a theory.

The african elephants elephant has large ears to help it stay cool.

State the zoologist’s hypothesis about African elephants.

Hot

Cool

State the zoologist’s conclusion.

The hypothesis is supported.

Hot

Cool

Explain what the conclusion was based on.

The conclusion was based on data (temperature.)

Hot

Cool

State whether the data was quantitative or qualitative, and explain your answer.

Quantitative because you can count degrees.

Explain the purpose of doing background research.

No natural predators

Intimidate with their tusks, not their ears

The African savanna is extremely hot

X XTo narrow down the hypothesis and make it more specific.

Explain why the supported hypothesis is not yet a theory.

It must be tested many times with different African animals.

The zoologist began this process by making observations. This is NOT a step of the scientific method. What is the purpose of making observations?

Observation leads to inference, which leads to asking a question.