1. Tree clearing
2. Burning of fossil fuels
3. Warms the atmosphere

•Collisions between the earth and large asteroids 

•New species

•Extinctions

•8 million to 100 million species

•1.9 million identified

•Unidentified are mostly in rain forests and oceans

•Species diversity

•Genetic diversity

•Ecosystem diversity

•Biomes: regions with distinct climates/species

•Functional diversity

•Biodiversity is an important part of natural capital

•Huge body of evidence

•Fossils-Physical evidence of ancient organisms

•Reveal what their external structures looked like

•Fossil record: entire body of fossil evidence

•Only have fossils of 1% of all species that lived on earth

•Populations evolve by becoming genetically different

•Genetic variations

•First step in biological evolution

•Occurs through mutations in reproductive cells

•Mutations: random changes in DNA molecules

•Natural selection: acts on individuals

•Second step in biological evolution

•Adaptation may lead to differential reproduction

•Genetic resistance: ability of one or more members of a population to resist a chemical designed to kill it
•Adaptive genetic traits must precede change in the environmental conditions

•Reproductive capacity

•Species that reproduce rapidly and in large numbers are better able to adapt

•Tectonic plates affect evolution and the location of life on earth

•Locations of continents and oceans have shifted

•Species physically move, or adapt, or form new species through natural selection

•Geographic isolation: happens first; physical isolation of populations for a long period

•Reproductive isolation: mutations and natural selection in geographically isolated populations lead to inability to produce viable offspring when members of two different populations mate

•Biological extinction

•Local extinction

•Endemic species 

•Found only in one area

•Particularly vulnerable

•Background extinction: typical low rate of extinction

•Mass extinction: 3-5 over 500 million years

•Photosynthesis:

•CO2 + H2O + sunlight → glucose + oxygen

•Chemosynthesis

•Consumers, heterotrophs

•Primary consumers = herbivores

•Secondary consumers

•Tertiary consumers

•Carnivores, Omnivores

•Decomposers

•Consumers that release nutrients

•Bacteria

•Fungi

•Detritivores

•Feed on dead bodies of other organisms

•Earthworms

•Vultures

•Aerobic respiration

•Using oxygen to turn glucose back to carbon dioxide and water

•

•Anaerobic respiration = fermentation

•End products are carbon compounds such as methane or acetic acid

•Movement of energy and nutrients from one trophic level to the next

•Photosynthesis → feeding → decomposition

•Food web

•Network of interconnected food chains

•Dry weight of all organic matter of a given trophic level in a food chain or food web

•Decreases at each higher trophic level due to heat loss

•Pyramid of energy flow

•90% of energy lost with each transfer

•Less chemical energy for higher trophic levels

•Species richness: 

The number of different species in a given area

•Species evenness: 

Comparative number of individuals

•Diversity varies with geographical location

•The most species-rich communities

•Species equilibrium model, theory of island biogeography

Rate of new species immigrating should balance with the rate of species extinction

Island size and distance from the mainland need to be considered
•Species richness seems to increase productivity and stability or sustainability, and provide insurance against catastrophe

•How much species richness is needed is debatable

•Provide early warning of damage to a community

•Can monitor environmental quality 

•Trout

•Birds

•Butterflies

•Frogs

•Pollinators

•Top predators

•Elephants

•Beavers