Systems on Earth System: A group of interacting, interrelated, or interdependent elements forming a complex whole. Synergy: The interaction of two or more agents or forces so that their combined effect is greater than the sum of their individual effects. System > Sum of its Parts
Cells Tissues Organs Organ Systems Individuals Populations Communities Ecosystems Systems on Earth
The Gaia Hypothesis James Lovelock Independent scientist Earth made of different functioning units that interact with each other Changed focus of environmental movement
Systems All systems have Inputs Outputs Processes
Scale of Systems
Types of Systems Open Closed Isolated
Open System Exchange of matter and energy
Closed System Exchange of energy only.
Isolated System No exchange of energy or matter Do not exist naturally Possibly the universe?
Energy Energy in all types of systems follows the laws of thermodynamics. Energy is released in the form of light and heat. Energy can be “stored” in the bonds or organic molecules.
1st Law of Thermodynamics Law of Conservation of Energy Energy can neither be created nor destroyed. Energy can only change forms. Cells cannot produce energy – they burn sugars to produce ATP (respiration). Plant cells convert the sun’s energy to sugar, which they burn for energy.
2nd Law of Thermodynamics Energy flows from high quality to low quality. Energy is lost during every conversion between forms Energy = Work + Heat As systems lose energy they become more disorganized – more entropy The sun supplies constant, high quality energy
Life and the 2nd Law Life is a struggle against entropy. Organization takes energy!
ENERGY is the foundation of all ecosystems
Equilibrium Ecosystems are open systems Open systems tend to exist in a state of balance, or equilibrium Static equilibrium Components of the system stay unchanged Ex: makeup of Earth’s crust Dynamic equilibrium The system is unstable on the short term Stays unchanged over the long term
Regulation of Systems Systems are managed by feedback loops Positive feedback system Cause change in the same direction as the system
Regulation of Systems Negative feedback systems Cause change in the opposite direction from the original system Like a furnace/ thermostat in your house
Processes Within Ecosystems Both materials and energy move through ecosystems Materials can be recycled Energy cannot
Two Types of Processes Transfers Require little energy Change in location of material or energy Examples Movement of materials when one organism eats another Movement of water through runoff Heat energy moving in ocean currents, air masses
Two Types of Processes Transformations Change in form of the energy or materials Requires more energy Examples: Conversion of energy from glucose to ATP during respiration Conversion of sun’s energy from light to organic molecules during photosynthesis Evaporation or condensation of water Burning of fossil fuels
Diagramming Systems Storage Parts of a system where energy or materials accumulate Drawn as a box (think engine in a box) Flows Inputs – movement into the storage Outputs – movement out of the storage Can be transfers or transformations