1. 1 LIFE…AS WE KNOW IT!!

2. 2 Biosphere : layer of Earth that supports life roughly 13 miles thick ( 7 miles into atmosphere and 7 miles down into the oceans !!!) Biosphere : layer of Earth that supports life roughly 13 miles thick ( 7 miles into atmosphere and 7 miles down into the oceans !!!) Biomes : large regions of the globe defined by similar climate (T and precipitation) and vegetation Biomes : large regions of the globe defined by similar climate (T and precipitation) and vegetation –specific place on the map Ecosystems: All of the living organisms and the nonliving environment in a particular place Ecosystems: All of the living organisms and the nonliving environment in a particular place ( lg. ecosystems – small ecosystems) ( lg. ecosystems – small ecosystems)

3. 3 http://www.blueplanetbiomes.org/world_biomes.htm

4. 4 POPULATIONS: group of organisms, in same species (able to interbreed), in same area, at same time…“the 3 S’s” 5.1

5. 5 Population Dynamics Populations change constantly in size and composition…what types of things in the environment limit the growth of a population? ***ANSWER! Populations change constantly in size and composition…what types of things in the environment limit the growth of a population? ***ANSWER! –Limited food and water –Predator increase (including hunting) –Climate and Weather conditions (drought, flood, tornado) –Diseases (immigration; close contact) –Space –Pollution They experience changes in their gene pool over time: They experience changes in their gene pool over time: –births, deaths, immigration (into), emigration (out of)

6. 6 2 FACTORS THAT LIMIT POPULATION GROWTH 1. Density-dependent factors = dependent on 1. Density-dependent factors = dependent on the # of organisms in a given area. the # of organisms in a given area. *limited resources, predation, disease *intraspecific (between members of the same species) and interspecific (between members of different and interspecific (between members of different species) competition species) competition 2. Density-independent factors = 2. Density-independent factors = environmental conditions that limit growth (regardless of # of organisms). (regardless of # of organisms). *weather and climate are the most impt. * “natural” disasters (flood, fire, tornado, hurricane, etc.) etc.)

7. 7 Cover up!!!!!!

8. 8 Abiotic vs. Biotic Factors (that affect population growth/decline) Abiotic: water, shelter, space, weather, climate, sunlight, nutrients (soil). Abiotic: water, shelter, space, weather, climate, sunlight, nutrients (soil). Biotic: predation, disease & parasitism, food availability, mating, human impacts (disrupting habitats, introducing diseases, introducing nonnative species) Biotic: predation, disease & parasitism, food availability, mating, human impacts (disrupting habitats, introducing diseases, introducing nonnative species)

9. 9 Growth Curves models that explain/depict how populations change over time. Growth Curves models that explain/depict how populations change over time. 2 Types: 2 Types: 1. Exponential: “J” shaped curve -rate of growth stays the same…continuous -population size increases steadily -ex. bacteria 2. Logistic: “S” shaped curve -“J” shaped that is limited by a density-dependent factor factor -death rate = birth rate -shows carrying capacity = the population size (max. #) that an environment can support.

10. 10 examples Exponential growth Exponential growth Logistic growth Logistic growth

11. 11

12. 12 Checking for understanding (3 parts) COMPLETE THE FOLLOWING (either on your iPad---then email to me; OR on a half sheet of paper): COMPLETE THE FOLLOWING (either on your iPad---then email to me; OR on a half sheet of paper): Answer reading check question after reading “Human Population” pg. 107 Answer reading check question after reading “Human Population” pg. 107 Graphing: #7 on pg. 107 Graphing: #7 on pg. 107 Pg. 103 Fig. 1: What distinguishes one zebra population from another zebra population? Pg. 103 Fig. 1: What distinguishes one zebra population from another zebra population?