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Populations and Growth

Populations and Growth. Population Dispersion. Survivorship Curves. Type I Few offspring Low infant mortality Parental care of young Most survive until old age Large mammals, including humans. Survivorship Curves. Type II Equal chance of living or dying throughout the lifetime

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Populations and Growth

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  1. Populations and Growth

  2. Population Dispersion

  3. Survivorship Curves • Type I • Few offspring • Low infant mortality • Parental care of young • Most survive until old age • Large mammals, including humans

  4. Survivorship Curves • Type II • Equal chance of living or dying throughout the lifetime • Birds, reptiles, small mammals

  5. Survivorship Curves • Type III • High infant mortality rate • Many offspring • No parental care • Invertebrates, fish, amphibians, and plants

  6. Changes in Population Size • Growth factors • Immigration: individuals moving into a population • Births • Shrinking factors • Emigration: individuals moving out of a population • Deaths

  7. Exponential Growth • Early phase of growth • High availability of resources • Little competition • Little predation

  8. Logistic Growth • Limits on growth appear • Competition for resources • Predation • Parasitism • Illness

  9. Human Population Growth Are humans in exponential or logistic growth?

  10. U.S. Population Density - 2000 People per square mile 0-1 (white) 10-24 (green) 100-249 (blue) 1-4 (yellow) 25-49 (teal) 250-66,995 (dark blue) 5-9 (yellow-green) 50-99 (dark teal)

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