Survival Factors

​Factors such as food, nutrients, water, and space must be available for a population to be healthy.

These are called survival factors.

What happens when one of those factors become insufficient?

How would they affect population growth.

Survival Factors

A historically significant famine occurred in the 1800s in Ireland. During this time, a disease caused the country to lose much of the potato crop.

How do you think the population of Ireland responded to not having food?

Potato Famine

When resources become more limited, population growth will appear as an S-shaped curve when graphed.

Competition for resources like food and space causes the growth rate to stop increasing, so the population levels off.

This flat upper line on a growth curve represents the population limit of that ecosystem.

Math... yikes... let's look at it.

Survival Factors and Population Growth

Maya bought 18 apples. She used 50% of the apples to make apple pie and mixed 1/3 of the apples with other fruit to make a salad. How many apples are left?

More Math

If there are 12 hamburgers at a lunch table and 24 people sit down at the table, will everyone be able to eat? At first, maybe the people split the hamburgers in half, but if more and more people keep coming to sit at the lunch table... what will happen?

This is similar to what happens in nature. However, in nature, organisms that cannot get food will die or find a new place to live. It is possible for any resource to become limited but a resource such as food can have dramatic consequences on a population.

More Math

Small Population = Plenty of Food

Average Population = Average Amount of Food

Large Population = Small Amount of Food

What happens with less food?

Resources

Other factors impacting survival include light, water, nutrients or minerals, oxygen, the ability of an ecosystem to recycle nutrients and waste, diseases and parasites, temperature, space, and predation.

Other Factors