1. Biology
Evolution
8. Evolution is the result of genetic changes that occur in constantly changing environments. As a basis for understanding this concept:
Students know how natural selection determines the differential survival of groups of organisms.
b. Students know a great diversity of species increases the chance that at least some organisms survive major changes in the environment.
e. Students know how to analyze fossil evidence with regard to biological diversity, episodic speciation, and mass extinction.

2. Natural Selection
NATURAL SELECTION – organisms best suited to their environments will survive and reproduce more successfully than others
Natural Selection is not an active, purposeful process (it is not a choice )
Some traits in one environment are not favorable in another. Organisms with a favorable trait have an ADAPTIVE ADVANTAGE.
Std. 7a: Natural Selection acts on PHENOTYPE
How one behaves, reproduces, eats, etc. determines survival in an environment no matter how good one’s genes are!

3. Evidence for evolution
FOSSILS
Any preserved remnant or impression left behind by organisms of the past

4. Compare these embryos

5. Ecology
Ecology
6. Stability in an ecosystem is a balance between competing effects. As a basis for understanding this concept:
a. Students know biodiversity is the sum total of different kinds of organisms and is affected by alterations of habitats.
b. Students know how to analyze changes in an ecosystem resulting from changes in climate, human activity, introduction of nonnative species, or changes in population size.
c. Students know how fluctuations in population size in an ecosystem are determined by the relative rates of birth, immigration, emigration, and death.
d. Students know how water, carbon, and nitrogen cycle between abiotic resources and organic matter in the ecosystem and how oxygen cycles through photosynthesis and respiration.
e. Students know a vital part of an ecosystem is the stability of its producers and decomposers.
f. Students know at each link in a food web some energy is stored in newly made structures but much energy is dissipated into the environment as heat. This dissipation may be represented in an energy pyramid.

6. ECOLOGY is the study of how living organisms interact with their environments and with each other.
A particular environment being studied is called an ECOSYSTEM.
Biotic + Abiotic = ecosystem

7. Things that lead to unhealthy ecosystems:
CLIMATE CHANGE – Shift in normal temperatures and weather patterns
Examples: GLOBAL WARMING, DESERTIFICATION
HUMAN ACTIVITY – Any human interference with an area
Examples: POLLUTION, OVERPOPULATION, LAND USE
OVERPOPULATION – Organisms must maintain a balance in population numbers to be sure that there are adequate resources in an area to support the population
NON-NATIVE SPECIES– Organisms that are not native to an area can cause serious ecological damage by taking over habitat and food resources that the existing species rely on

8. ENERGY PYRAMID – a diagram showing how energy is transferred from producer to primary consumer to secondary consumer etc…
-Typically, the amount of energy transferred from one level to the next is only 10% of the level below it.
-There are typically MORE producers than consumers in an area because less energy is available for the higher-level consumers to sustain a large population.

9. Food Web
A vital part of an ecosystem is the stability of its decomposers and producers. Why? Where is the energy coming from the fuel the food web?

10. Population Size Changes
(Birth + immigration) – (Death + emigration) All the individuals adding to the population minus the number of individuals leaving the population.

11. Limiting Factors: conditions which control a population’s ability to grow
Carrying Capacity: the limited number of individuals in a population that a particular environment can support