Environmental Effects
Stochastic variation in the environment (year to year variation in rainfall, temperature) can produce temporally correlated birth and death rates (i.e. 'good' years when birth rates are high and death rates are low and 'bad' years when birth rates are low and death rates are high) that lead to fluctuations in the population size. Again, smaller populations are more likely to go extinct due to these environmentally generated population fluctuations than are large populations.
Read more about this topic: Small Population Size
Famous quotes containing the word effects:
“Virtues are not emotions. Emotions are movements of appetite, virtues dispositions of appetite towards movement. Moreover emotions can be good or bad, reasonable or unreasonable; whereas virtues dispose us only to good. Emotions arise in the appetite and are brought into conformity with reason; virtues are effects of reason achieving themselves in reasonable movements of the appetites. Balanced emotions are virtue’s effect, not its substance.”
—Thomas Aquinas (c. 1225–1274)