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207 Causes of Pop Ch
Term | Definition |
---|---|
the four causes of population change - | birth immigration death emigration |
The causes of population increase - | births and immigration |
The causes of population decrease - | deaths and emigration |
Immigration - | Migration into a population |
The formula for population change - | (births + immigration) - (deaths + emigration) |
Emigration - | Migration out of a population |
Effects of increased food - | Increases the birth rate Decreases the death rate |
Effects decreased food - | Lowers birth rate because individuals are less healthy Increases death rate because individuals starve and, because they are less healthy, they are more susceptible to disease |
Effects of increase in predators - | Increased death rate |
Effect of increased hunting - | Increased death rate |
Effects of competition - | Increase in death rate because there's less food which leads to starvation Decrease in birth rate because there's less food which means individuals are less healthy |
net effect - | overall result In this case, the actual population change after adding births and immigration and subtracting deaths and emigration AKA net population change |
Equilibrium - | Balance When B + I = D + E |