UNIT 3 TOPIC OVERVIEW

3.1 Generalist vs. Specialist Species

Generalists: broad niches, adaptable.
Specialists: narrow niches, specific needs.

Generalist: raccoon, human.
Specialist: panda, koala.

Niche, adaptability

3.2 K-Selected vs. r-Selected Species

K: few offspring, high parental care, stable pop.
r: many offspring, low care, unstable pop.

K: elephants, humans.
r: insects, fish.

Reproductive strategy, carrying capacity

3.3 Survivorship Curves

Type I: low early death.
Type II: constant death rate.
Type III: high early death.

Type I: humans.
Type II: birds.
Type III: fish.

Life expectancy, mortality

3.4 Carrying Capacity (K)

Max population an environment can sustain. Overshoot → dieback.

Deer population in forest, yeast in lab.

Logistic growth, resource limits

3.5 Population Growth & Resource Availability

Abundant resources → exponential growth.
Limited → logistic growth.

Yeast culture, human food limits.

Limiting factor, growth curve

3.6 Age Structure Diagrams

Show population by age/sex → predict trends.

Pyramid: fast growth.
Stable: even.
Inverted: decline.

Population pyramid, dependency ratio

3.7 Total Fertility Rate (TFR)

Avg. children per woman.
Replacement = ~2.1.

High TFR: Niger.
Low TFR: Japan.

Fertility, replacement level

3.8 Human Population Dynamics

Growth = (births + immigration) − (deaths + emigration).
Rule of 70 → doubling time.

U.S. immigration, global growth.

Doubling time, migration

3.9 Demographic Transition Model (DTM)

4–5 stages from high to low birth/death rates.
Industrialization reduces birth rates.

Stage 1: pre-industrial.
Stage 4: post-industrial.

Birth rate, death rate, development