Population Growth

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1

Slide 1

Populations and Growth

Slide 2

Population Dispersion

Slide 3

Survivorship Curves

Type I

Few offspring

Low infant mortality

Parental care of young

Most survive until old age

Large mammals, including humans

Slide 4

Survivorship Curves

Type II

Equal chance of living or dying throughout the lifetime

Birds, reptiles, small mammals

Slide 5

Survivorship Curves

Type III

High infant mortality rate

Many offspring

No parental care

Invertebrates, fish, amphibians, and plants

Slide 6

Changes in Population Size

Growth factors

Immigration: individuals moving into a population

Births

Shrinking factors

Emigration: individuals moving out of a population

Deaths

Slide 7

Exponential Growth

Early phase of growth

High availability of resources

Little competition

Little predation

Slide 8

Logistic Growth

Limits on growth appear

Competition for resources

Predation

Parasitism

Illness

Slide 9

Human Population Growth

Are humans in exponential or logistic growth?

Slide 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)