BSCI 160 Exam 1 Shapiro

organismal ecology

individual interactions with environment

population ecology

factors regulating population growth rates and population size

community ecology

interactions among different species in an area

ecosystem

interactions between communities and their environments

Why does it get colder further from the equator?

Higher latitudes cause the rays to hit the earth at a lower angle causing less energy causing less heat

Hadley Cell

a large-scale atmospheric convection cell in which air rises at the equator and sinks at medium latitudes, typically about 30° north or south.

Corolis effect

in northern hemisphere, apparent deflection to the right; in southern hemisphere, apparent deflection to the left

Why do we have seasons?

The tilt of the Earth's axis

equator

0 degrees latitude

arctic circle

66 N southernmost latitude in the N. Hemisphere at which sun can remain above or below the horizon for 24 hours (at June & December solstices, respectively)

Anarctic Circle

66 S northernmost latitude in the S. Hemisphere at which sun can remain above or below the horizon for 24 hours (at December & June solstices, respectively)

Tropic of Cancer

23 N most northern latitude at which sun can be directly overhead (on June solstice, when N. Hemisphere is maximally tilted toward Sun)

Tropic of Capricorn

23 S most southern latitude at which sun can be directly overhead (on December solstice, when S. Hemisphere is maximally tilted toward Sun)

rain shadow

a region with dry conditions found on the leeward side of a mountain range as a result of humid winds from the ocean causing precipitation on the windward side

Biomes

major life zones characterized by vegetation type or physical environment

mark and recapture

capturing and marking organisms, then recapturing them and counting how many are marked

c/N = rc/n

per capita growth rate

r = b - d

life history

Traits that affect an organism's schedule of reproduction and survival.

survivorship curve

Graph showing the number of survivors in different age groups for a particular species.

Fecundity Curves

age v fertility rate

life table

age-specific summary of survival & reproduction patterns in a population

rmax

maximum per capita growth rate of population

(max births, min deaths)

density dependent

Growth rate depends on N

carrying capacity (K)

Largest number of individuals of a population that a environment can support

exponential growth

when N=0, ((K/N)/K)=1

dn/dt = rmaxN

logistic growth

dn/dt = rmaxN((K/N)/K)

r decreases and N increases

12,000 years ago

hunting, gathering

5 million humans

10,000-8,000- 1650 A.D.

agriculture

settled lifestyle is promoted more

more births; less deaths

1650-present

major technical advances

major increase in birth; major decrease in deaths

N has significantly increased (exponential)

World Population

7.9 billion

recent average doubling time

50 years

recent average time to add a billion people

10 years

projected growth slowing

8 billion ~ 2023

9 billion ~ 2037

10 billion ~ 2055

population momentum

The propensity for a growing population to continue growing even through fertility is declining because of their young age distribution

demographic transition

Industrialization

more births; less deaths

ecological footprint

land and water area needed to produce resources and absorb waste

growth rate (r) has decreased in 50 years but...

r is still > 0

population momentum

ongoing demographic transitions

=> all lead to N still increasing