Mr. Lima explains how density-dependent and density-independent factors affect an ecosystem's carrying capacity in reference to a population and limits its growth. [12:18]

Explains how energy flows in ecosystems. Energy enters via producers through photosynthesis or chemosynthesis. Producers and consumers release the energy from food through cellular respiration. An explanation of gross primary...

Paul Andersen explains how the Earth's climate will natural change due to interactions between the Sun and Earth, volcanism, and plate tectonics. Species may go extinct leading to adaptive radiation or may move to a suitable climate....

In this video, a teacher conducts a science lesson where students create a tableau of an ecosystem. As the teacher calls upon them, each student explains where they get their energy from and where it goes in the ecosystem. The teacher...

As our planet has coughed up new oceanic islands and ripped its land masses apart, organisms have found themselves stranded in new environments. And every time, evolution has helped them adapt. [1:50] Play the Evolution Lab:...

Find out the effects that climate change can have, and how one small change in an ecosystem can throw everything off in an ecosystem. [3:40]

Find out how humans have been changing our environments for a long time. [4:56]

In this segment, we'll listen in on a phone call from Atlantis to Antarctica, to check in with researchers studying organisms that live in extreme environments: one group of scientists is working with the submersible Alvin, studying...

This lesson will define ecology, natural environment, ecosystem, and environmental deficit, while delineating the formula for calculating human impact on the environment. It is 2 of 3 in the series titled "Environmental Concepts."

This lesson will present the levels of organization of living things. It is 3 of 6 in the series titled "Levels of Organization."

This lesson will introduce abiotic and biotic factors, giving examples and comparing/contrasting the two. It is 3 of 4 in the series titled "Abiotic and Biotic Factors." [1:15]