Stickleback Evolution Pre-Lab

Stickleback Evolution

Pre-Lab

DE Biology - Adapted from HHMI's "Making of the Fittest: Evolving Switches, Evolving Bodies" video + worksheets

Multiple Select

We'll be using stickleback fish as a model organism in our virtual lab.

What do you think the term "model organism" means?

• It's a plastic model we can take apart and explore.

• It's a model displayed in a natural history museum.

• It's a specific example with lots of data.

• It's a specific example that is easy to work with and study.

Multiple Choice

When fish "spawn", the females lay eggs that the males fertilize. What kind of water do sticklebacks spawn in?

• freshwater

• saltwater

• brackish water

Reorder

How did the original marine population of sticklebacks end up living in lakes?

• glaciers melted

• new rivers drained to the ocean

• some of the ice-free land rose up

• upstream water became a lake

• sticklebacks went upstream to spawn

1

2

3

4

5

• 1
• 2
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• 5

Open Ended

Why do you think the scientists like using fish that live in hundreds of post-glacial lakes? (Hint: Think about experimental design.)

Drag and Drop

In the ocean, predatory fish can swallow sticklebacks ​

Placeholder

spines. In lakes, predatory insects can catch sticklebacks ​

Placeholder

spines.

Drag these tiles and drop them in the correct blank above

without

with

Multiple Choice

Which sticklebacks get a fitness advantage from spines?

• lake-dwelling

• ocean-dwelling

Multiple Choice

The loss of stickleback pelvic spines is similar to the loss of which body parts in some other four-legged vertebrates?

• arms

• legs

• tails

• hands

Open Ended

Can you think of any other vertebrate animals whose evolutionary histories included the loss of hind limbs?

Drag and Drop

The scientists expected the spine / no-spine trait to be controlled by a ​

Placeholder

, but found that it was controlled by a ​

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that regulates

Placeholder

.

Drag these tiles and drop them in the correct blank above

gene

switch

gene expression

Open Ended

Using stickleback spines as a model, what can we say about the relationship between natural selection and mutation in the evolution of populations?

Poll

You hear someone say, "Beneficial changes don't come from mutations."

How do you respond?

• So true!

• Umm...have you ever heard about stickleback fish?

• Not true!

• [no response - let it slide]