Question

Which of the following is a density-independent limiting factor?

A. earthquake

B. disease

C. emigration

D. parasitism
(MEDAL)

Answer 1

Let's talk about "density independent," first.

Density Independent means that whatever is happening doesn't care how many people are in an area.

We have four choices.
And each of them is either....

1. Density DEPENDENT
or...
2. Density INDEPENDENT

Remember,
Density INDEPENDENT is where something happens, REGARDLESS of human population size.

~~~~~~~~~~~~

Let's look at....B, for example.

Disease.

Here's a fact:
The MORE people there are, in a given area,
the MORE likely it is that someone will get sick.

Therefore, DISEASE is Density DEPENDENT.
It's not our answer.

~~~~~~~~~~~~~~~

So again,
what we can do is take a look at all four choices.

Which one of the choices DOES NOT CARE how many people there are, in a given area?

Answer 2

a

Answer 3

Yes, that's right.

Earthquakes do not give a crap about how many people there are, in an area.
Earthquakes will happen whenever the hell they feel like happening.