Population Ecology: Species Types, Growth, and Demographic Trends

Generalist Species

Adaptable to a wide range of environments and diets.

Examples of Generalist Species

Raccoons, coyotes, humans.

Advantage of Generalist Species

Advantageous in unstable or changing environments.

Specialist Species

Require specific environmental conditions and diets.

Examples of Specialist Species

Koalas (eucalyptus leaves), pandas (bamboo).

Advantage of Specialist Species

Advantageous in stable environments but vulnerable to changes.

K-Selected Species

Produce fewer offspring with high parental investment.

Examples of K-Selected Species

Elephants, humans.

Adaptation of K-Selected Species

Adapted to stable environments; population size stabilizes near carrying capacity.

r-Selected Species

Produce many offspring with little parental care.

Examples of r-Selected Species

Insects, bacteria.

Adaptation of r-Selected Species

Adapted to unstable environments; population size fluctuates.

Type I Survivorship Curve

High survival rates in early and middle life, with a steep decline in older age.

Examples of Type I Survivorship Curve

Humans, elephants.

Type II Survivorship Curve

Constant mortality rate throughout the lifespan.

Examples of Type II Survivorship Curve

Songbirds, squirrels.

Type III Survivorship Curve

High mortality rates for the young, with few surviving to adulthood.

Examples of Type III Survivorship Curve

Fish, amphibians.

Carrying Capacity

The maximum number of individuals of a species that an environment can support indefinitely without degrading the habitat.

Impact of Exceeding Carrying Capacity

Can lead to resource depletion and environmental degradation.

Population Growth with Abundant Resources

Leads to exponential population growth.

Population Growth with Limited Resources

Results in logistic growth, where population size levels off as it approaches carrying capacity.

Key Factors Affecting Population Growth

Food availability, water supply, habitat space, predation and disease.

Age Structure Diagrams

Diagrams that show the distribution of individuals in different age groups within a population.

Types of Age Structure Diagrams

Expansive, Constrictive, Stationary.

Factors Affecting Total Fertility Rate (TFR) in Humans

Access to Family Planning, Education & Employment, Cultural Norms, Economic Factors.

Human Population Growth Factors

High birth rates, Improved healthcare, Immigration.

Human Population Decline Factors

Low birth rates, High death rates, Emigration.

Recent Trends in Global Fertility Rates

Have declined, leading to slower population growth.

Demographic Transition

A model that describes the transition of a country from high birth and death rates to low birth and death rates as it develops.

Stages of Demographic Transition

Pre-Industrial, Transitional, Industrial, Post-Industrial.

Implications of Demographic Transition

Changes in population growth, economic development, and social structures.