Introduction to Population Growth Models exam Flashcards
Introduction to Population Growth Models exam
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Population Growth Models
Mathematical frameworks used to predict changes in population size over time.What are the three main types of population growth models?
Linear, exponential, and logistic growth models.Closed Population
A population with no immigration or emigration, only birth and death rates affect population size.Homogeneous Environment
An environment where resources are evenly distributed and all individuals have equal access.Population Growth Rate (Δn/Δt)
The overall change in population size over a specific period of time.Per Capita Growth Rate (r)
The average population growth rate per individual.What does r max represent?
The maximum per capita growth rate under ideal conditions for a species.What assumptions are common to all three population growth models?
Closed population, homogeneous environment, and ignoring age structure, sex ratio, and external factors.Age Structure
The breakdown of age groups within a population.Sex Ratio
The ratio or proportion of males to females in a population.Density Independent Factors
External factors like tornadoes and hurricanes that affect population size regardless of density.What is the advantage of making assumptions in population growth models?
Simplification of the models.What is the disadvantage of making assumptions in population growth models?
Reduced accuracy of the models.How is the per capita population growth rate (r) calculated?
By dividing the population growth rate (Δn/Δt) by the initial population size (N₀).What happens to population size when r = 0?
The population size remains constant.What happens to population size when r < 0?
The population size decreases.What happens to population size when r > 0?
The population size increases.How is r defined in the linear population growth model?
As the population growth rate (Δn/Δt), not on a per capita basis.How is r defined in the exponential and logistic population growth models?
As the per capita population growth rate.What does the variable r dictate in population growth models?
How and how quickly the population size changes over time.What is the formula for population growth rate?
Δn/Δt, where Δn is the change in population size and Δt is the change in time.What is the formula for per capita population growth rate?
r = (Δn/Δt) / N₀, where N₀ is the initial population size.What is another way to calculate the per capita population growth rate?
r = b - d, where b is the per capita birth rate and d is the per capita death rate.What is the significance of r max being species-specific?
It is determined by the biology of the species and reflects ideal growth conditions.What is the impact of ignoring age structure in population growth models?
It simplifies the model but may reduce accuracy as age structure can significantly impact population growth.What is the impact of ignoring sex ratio in population growth models?
It simplifies the model but may reduce accuracy as sex ratio can significantly impact population growth.What is the impact of ignoring external factors in population growth models?
It simplifies the model but may reduce accuracy as external factors can significantly impact population size.Why are population growth models still useful despite their assumptions?
They provide a general idea and can still be used to make predictions, even if not perfectly accurate.