8.11 C Environmental Changes

1. 8.11 C Environmental Changes The student is expected to explore how short- and long- term environmental changes affect organisms and traits in subsequent populations.

2. Background Information A habitat is a place where a plant or animal lives, a kind of home base where conditions are suited to meet all of their needs. Habitats have these special characteristics: • There is enough food in the area and it is the right kind of food. • There is enough water in the area and it is the kind the animal or plant needs. • There is enough space for individual animals and populations of animals to grow and behave normally. • There is enough cover and shelter to protect the animal and allow them to breed and rear their offspring.

3. Background Info, continued • In their selected habitat, plants and animals also enjoy an optimal climate: the patterns of temperatures and precipitation are those that suit each living thing. • Most animals and plants are adapted to live in only one environment. • Changes in a habitat can come abruptly or gradually.

4. Types of Environmental Change Long-Term Environmental Changes • Occur over thousands to millions of years • Changes in atmospheric composition • Plate Tectonics • Climate Change • Changing brightness of the Sun • Frequency of meteor impacts One type of change can often cause another. For instance, shifting continents by continental drift has frequently resulted in global climate change and changing sea levels.

5. Types of Environmental Change Short Term Changes • Occur over days to hundreds of years • Natural habitat disturbances such as hurricanes, tornados, fires, earthquakes, floods, volcanic eruptions • Manmade habitat disturbances such as smog, pollution, housing developments, road construction, over-hunting. • Invasive Species Strange Days Watch Lake Victoria Segment • Rapid climate change Strange Days Caribou Population

6. Results of Long-Term Changes Over many generations, species can respond to environmental change in three ways. They can • Evolve to accommodate the changed environment, • Adaptation – Certain plants and animals develop characteristics that help them cope better than others of their species with their environment. Adaptations can help organisms obtain food and shelter, provide protection, produce and protect offspring, regulate body temperature, etc. Tree FrogMud SkipperCreeper Plants • Change their geographic distributions or behaviors to accommodate the changed environment, or Snow Monkeys • Go extinct. The Great Dying Examples of all three responses can be seen today and in the geologic record.

7. Results of Short-Term Changes Short Term Changes often happen abruptly, so species are much more at risk during short term changes. When there is a short term change organisms will • change their behavior to accommodate the changed environment, • move to a more accommodating environment, or • die. Climate Change Crow in the City Strange Days Overfishing