Task 1A: Extinction

honeybee mystery.pdf

Read this case study about the honeybee.

Answer this question:

Why does the extinction of any species have a major impact on biodiversity?

What causes an extinction?

Can't Adapt

The Haast's Eagle was a massive eagle in prehistoric times. This bird was big enough that it could have preyed on humans.

But, this bird was not able to adapt to the changing prey availability, and went extinct because humans hunted its food sources.

Isolation

The Guam Flying Fox (a bat) recently went extinct.

It was an endemic species, meaning it only lived in a small area.
This made it vulnerable to extinction because there were so few organisms with a narrow range of habitat.

Catastrophic Event

One of the most well-known mass extinctions was the disappearance of the dinosaurs.

This event was caused by a asteroid hitting the Earth. This was a major catastrophe that devastated life on Earth.

Based on the data we have, scientists say that Earth is entering a sixth major extinction.

While mass extinctions have a serious impact on the biodiversity of the Earth, they also provide an opportunity. After every mass extinction, lots of new species appear to fill those niches (roles in the ecosystem).

Look at the graph below. What do you notice happens after every mass extinction?

If you answered that new species appear and dominate the Earth, you are correct. The extinction of dinosaurs allowed us (humans) to appear and be the apex predators.

The only problem is that it takes millions of years for biodiversity to recover from a mass extinction. Usually, a mass extinction takes tens of thousands of years (which is fast in geology).

At the current rate of human influence, a mass extinction could occur in the span of 70-80 years with the same recovery time as a normal extinction. As a result, we need to change our behaviors before it's too late.

Checkpoint 1:

For this checkpoint, come to class to read about the Fate of Easter Island. You will then answer this question:

Do you think Easter Island serves as a cautionary tale for the planet as a whole?

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