BIO 102: Populations

Ecology

The study of organisms and their interactions with the biotic and abiotic components of their environments.

Biotic components

All the living organisms in an environment, including plants, animals, and microorganisms.

Abiotic components

Non-living elements such as water, soil, air, and climate that influence ecosystems.

Organismal Level

Focuses on individual organisms and their interactions with the environment.

Population Level

Involves groups of individuals of the same species existing in a specific area.

Community Level

Examines interactions between different species in an ecosystem.

Ecosystem Level

Looks at the interactions between communities and their environments, including nutrient cycles and energy flows.

Global Level

Encompasses ecological phenomena at a broader scale, such as climate change.

Population

A group of individuals of the same species living in the same area at the same time.

Life Table

A summary of the probability that an individual will survive and reproduce over time.

Type I Survivorship

Characterized by high survivorship throughout most of the life span with mortality concentrated in older age classes.

Type II Survivorship

Exhibits a constant mortality rate regardless of age, indicating an equal chance of dying at any age.

Type III Survivorship

Marked by high mortality rates for young individuals, but those that survive have a much higher chance of living long lives.

Net Reproductive Rate (R0)

The average number of female offspring produced per female over her lifetime, indicating potential for population growth.

Exponential Growth

Population growth under ideal conditions where the resources are unlimited, usually depicted by a J-shaped curve.

Logistic Growth

Population growth when resources become limited, leading to a slowing of growth as the population approaches its carrying capacity.

Carrying Capacity (K)

The maximum sustainable population size that a specific environment can support indefinitely.

Density-Dependent Factors

Biotic factors that affect population growth more intensely as the population density increases.

Density-Independent Factors

Abiotic factors that reduce population numbers irrespective of the population's density.

Genetic Drift

Random fluctuations in the frequencies of alleles from one generation to the next within a population.

Nitrogen Fixation

The process of converting atmospheric nitrogen gas into ammonia, making it usable for plants.

Plant Symbiosis

Mutualistic relationships between plants and other organisms, such as nitrogen-fixing bacteria and mycorrhizal fungi.