Ch. 20.1 Population Ecologypp.379-382

Population = group of the same species, in the same place, at the same time• the place can be defined

any way you decide• Pop. size = count• Pop. density = thickness

=

Population #1: 30 people in the gym

Population #2: 20 people in Mr. G’s room

Which has a higher size?Which has a higher density?

Ch. 20.1 Population Ecologypp.379-382

Pop. Size #1 = 30Pop. Density #1

Pop. Size #2 = 20Pop. Density #2=

. . . . . .. . . . .. . . . .. . . . .. . . . .. . . .

……….……….

←100 ft→

←30 ft→←

20 ft

→

←80

ft→

Ch. 20.1 Population Ecologypp.379-382

Pop. Size #1 = 30Pop. Density #1 =

= = 0.003

Pop. Size #2 = 20Pop. Density #2= = = .03

. . . . . .. . . . .. . . . .. . . . .. . . . .. . . .

……….……….

←100 ft→

←30 ft→←

20 ft

→

←80

ft→

Ch. 20.1 Population Ecologypp.379-382

Dispersion = spatial distribution of the population• How they are spread out

• Clumped

• Even

• Random

Name a population that might be:

Clumped:

Even:

Random:

:: :::

. . . . .

. . . . .

: . : . . : .

Ch. 20.1 Population Ecologypp.379-382

Dispersion = spatial distribution of the population• How they are spread out

• Clumped

• Even

• Random

Name a population that might be:

Clumped: • ducks on a pond• Humans in a city

Even:• Owls in a forest

Random: • Beetles in a forest

:: :::

. . . . .

. . . . .

: . : . . : .

Ch. 20.1 Population Ecologypp.379-382

Population Dynamics = how populations change• Dynamic = changing constantly

• Birth rate = births/time• Death rate = deaths/time• Life expectancy = how long

the average individual is expected to live

Why might the average woman live longer?

Is it because they are healthier or the average man lives shorter?

Ch. 20.1 Population Ecologypp.379-382

Age structure = distribution by age of individuals in a population

Ch. 20.1 Population Ecologypp.379-382

Survivorship curve = shows when populations die (how they survivor)Type I: few die early in

life, many die late in life (humans, elephants)

Type II: die equally throughout life (prey species, mice, squirrels, rabbits…)

Type III: many die early, few die late (insects, oysters, turtles)

Ch. 20.1 Population Ecologypp.379-382

OUT: Table 20-1 p. 380

1. Predict the Land Size of the countries from Largest to smallest.

2. Calculate the population of the U.S. in the year 2000 using the information from the table, if the U.S. has an area of 9,620,000 km2