Pollution and Habitat Destruction: The Human Factors Contributing To Endangerment & Extinction

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: What Is an Invasive Species? - Definition, List & Effects

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:07 Human Impacts
  • 1:06 Habitat Fragmentation
  • 2:24 Anthropogenic Pollution
  • 3:57 How Do We Help?
  • 4:45 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed
Lesson Transcript
Instructor: Laura Enzor

Laura has a Master's degree in Biology and is working on her PhD in Biology. She specializes in teaching Human Physiology at USC.

In this lesson you will learn about two ways humans contribute to species extinction. We break up habitats by building roads and clearing land, and we pollute both land and water. You will also learn about the specific terms used to describe the processes, habitat fragmentation and anthropogenic pollution.

Human Impacts

Ecosystems function quite well when left alone; they act like a balance. However, one small change to an ecosystem disturbs that balance, and humans are typically directly responsible for those changes. Due to practices such as destroying habitats for room to build and clearing land for crops and roads, as well as polluting the environment, humans are responsible for hundreds of species' extinctions (extinctions means 'ceasing to exist').

When humans alter the environment, there are consequences for the animals and plants that utilize that particular environment. When we break an ecosystem into smaller chunks by building structures or roads, this is termed 'habitat fragmentation' (fragmentation means to break into smaller chunks). When building, humans also inevitably pollute the environment as well. The term used to describe pollution that is caused by humans is 'anthropogenic.'

Habitat Fragmentation

When habitats are fragmented, the animals and plants in that habitat must in essence, relearn how to survive. Food resources that were once there may be gone, or their homes may have been destroyed. In some cases, the areas where young were once hatched or raised may be gone. This may cause many species to die off quickly, affecting the biodiversity, or variation of life, in a given habitat. Recall that ecosystems act like a balance. So, what happens when the scales are tipped in one direction or another?

Let's look at an example where a road and buildings were built in the middle of a forest. Before the habitat was fragmented, there were plants which fed several herbivores, or animals which only eat plants, such as deer and elk. These large animals in turn fed the carnivores, or animals which consume meat, such as wolves and mountain lions. With the destruction of many of the plant species, the herbivores start to die off because they don't have enough food. This causes the carnivores to die off because there aren't enough herbivores to sustain their population numbers. Within several months, this habitat is considered dead, as the animals which once lived within it are now gone.

Anthropogenic Pollution

The majority of pollution we see on a daily basis is the direct result of humans, and human actions contribute to pollution both on land and in water. Burning of non-renewable resources, or resources which are not easily regenerated, such as fossil fuels (oil), and throwing massive amounts of garbage into landfills are ways in which humans alter the atmosphere and land. Run-off from farms, which is filled with fertilizer, drastically changes both fresh and oceanic waters, which has direct implications for organisms which live in the water.

So how do these processes affect ecosystems? If we follow run-off from an agricultural farm to the ocean, we see that sediments from that farm are carried into the water, as well as fertilizers. The sediments block sunlight and inhibit the growth of organisms, which photosynthesize, or get their energy from the sunlight, such as corals and algae. These animals and plants provide food for grazing fish, which in turn provide food for larger predators, such as barracuda and sharks.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account