Lecture 3 - Human Population

Question 1

Population ecology applied to human population
- Definition of population
- Applied to humans

Answer 1

Population: Individuals of the same species that co-occur in the same space and time

All humans are considered one population because we can travel/disperse so easily

Question 2

Definitions: Population density and Population distribution/dispersion

Answer 2

Population density: the number of individuals per unit area

Population distribution/dispersion: the spatial arrangement of the individuals within the population
- Random
- Regular/Even
- Clumped

Question 3

Determinant and shaping factors of populations:

Answer 3

• Current size, birth & death rates, immigrations & emigrations, carrying capacity
• Age structure, sex ratio

Question 4

Age structure

Answer 4

Age distribution is affected by:
- periods of successful reproduction
- periods of high and low juvenile and adult survival
- whether the older individuals in a population are being replaced by younger individuals
- whether population is declining

Age-class structures of human populations
- pyramid = expanding

Question 5

Carrying capacity and human population: is it a logistic growth?

Answer 5

Carrying Capacity: The number of individuals of a particular species the local environment can support
- When the size of a population reaches carrying capacity, population growth “will” stop

For humans:
- cultural evolution and technological advancements
- we enhanced our ability to exploit natural resources through innovation
- effective carrying capacity of our ecosystems is difficult to calculate

Logistic Population Growth
- if a population starts at a small size, it will initially grow rapidly, then growth slows and eventually stops; stabilizing at a population size of K, carrying capacity

Question 6

Where on the planet is population growing more?

Answer 6

Less developed countries will account for 95% of population growth in the future. Wealthy nations use the most resources now, but emerging economies are catching up fast.
- Asia and Africa

Question 7

What is Malthusian catastrophism:
- Fate of human population uncontrolled growth
- Malthusian trap
- Was Malthus right? Why did his predictions turn out wrong?

Answer 7

Catastrophism: uncontrolled growth of the human population could lead to a population crash due to: pandemic, famine, decline of carrying capacity, nuclear holocaust, natural catastrophe

If population rates grow geometrically but food abundance increases arithmetically, then humans will run out of food, leading to ward, disease, and general chaos.

Malthusian trap: resources increase, wealth increases, pop increases, pressure on resource = dip, living standard decreases (cyclic)

Globally, no. Broke out of the Trap with the Industrial Revolution.

Question 8

Definition of ecological footprint vs. biocapacity

Answer 8

Ecological footprint: a tool used to express the environmental impact of an individual (per capita) or a population or a country. Includes:
- land/water required for crops/grazing
- resources to produce consumable products
- land we physically occupy
- resources required to offset carbon emission and other waste products

Biocapacity: ability of an area’s ecosystems to regenerate renewable resources

Ecological deficit: footprint larger than biological capcity for replenishment

Question 9

What are possible solutions

Answer 9

What can we do?
1. Decrease births
2. Increase deaths
3. HAVE SMALLER FOOTPRINTS
- use less
- produce better
- cultural changes (ex. agricultural revolution, industrial-medical revolution, information-globalization revolution)

Solutions?
1. Redirect Financial Flows
2. Preserve Natural Capital
3. Equitable Resource Governance