15.1 Life in the Earth System

KEY CONCEPT The biosphere is one of Earth’s four interconnected systems.

15.1 Life in the Earth System

The biosphere is the portion of Earth that is inhabited by life.

• The biosphere includes all ecosystems.– one of Earth’s systems

– includes the biota, all the living things in the biosphere

15.1 Life in the Earth System

• There are three other Earth systems.

– hydrosphere—water, ice, and water vapor

– atmosphere—air blanketing Earth’s solid and liquid surface

– geosphere—geologic features above and below Earth’s surface

15.1 Life in the Earth System

Biotic and abiotic factors interact in the biosphere.

• All four Earth systems are interconnected.

• The Gaia hypothesis considers Earth as a kind of living organism.– Earth systems

interact to yield a biosphere capable of supporting life.

– It was developed by James Lovelock and Lynn Margulis.