Are humans really Earth's most dominant species? Let's put all of the planet's living things on a scale and see what has amassed the most mass. This week we break down the concept of "biomass" to judge Earth's living things from top to bottom, and see how humans have changed the world.

Originally released by Knowledgemotion, 2018. Streaming video file encoded with permission for digital streaming by Infobase on February 21, 2020.

Which Life Form REALLY Dominates Earth? (6:23); .