Populations and Ecosystems

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# Populations and Ecosystems - PowerPoint PPT Presentation

## Populations and Ecosystems

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##### Presentation Transcript

1. Populations and Ecosystems

2. Population • All the individuals of a species that are living in an area at one time.

3. Milkweed Bug Reflection • How big was your population of milkweed bugs? • Will the population continue to grow? • How big will the population be in a month? • How big will the population be in a year?

4. Reproductive Potential • Every population has the potential to increase in size. Some populations have the potential for slow, steady growth; others have the potential to increase rapidly. If you have the proper information at hand , you can calculate the potential for population growth for any organism. The theoretical unlimited growth of a population over time is its reproductive potential.

5. Determining Reproductive Potential • What information would you need in order to predict the size of the population in the future?

6. Milkweed Bug Reproductive Potential • Entomologists have discovered some general information about the lives of milkweed bugs living in the wild. That information is written on your sheet in the question and answer chart. • Your observations from last year should have provided similar information for the indoor milkweed bugs. • Based on the information at had, you should be able to figure out how many bugs will be in the population after a month, 2 months or a year, if nothing limits population growth

7. Prediction: • Predict how many milkweed bugs will be in the population if they start with just one adult male and one adult female bug, and the population reproduces without limitation for a year.

8. Reminders: • Without any limitation on population growth, every egg produces a new individual in the population and every individual lives out its natural life, 4 months. • Only females produce eggs. Half the population is female. • Both male and female bugs are 2 months old when they reach maturity and mate, and the females produce 100 eggs • When a generation reaches maturity at 2 months, its parents are 4 months old and they die. Dead bugs must be subtracted from the population • The population at any time is the number of immature milkweed bugs plus their parents, minus their grandparents.