Natural increase leads to population growth because it reflects the difference between the birth rate and the death rate. When the birth rate exceeds the death rate, more individuals are being born than are dying, resulting in a net increase in the population size.
In simpler terms:
- Birth Rate: The number of live births per 1,000 people in a year.
- Death Rate: The number of deaths per 1,000 people in a year.
- Natural Increase: Occurs when the birth rate is higher than the death rate.
Therefore, if a population experiences a birth rate of 20 per 1,000 people and a death rate of 8 per 1,000 people, the natural increase is 12 per 1,000 people. This positive difference contributes to the overall growth of the population. A sustained natural increase over time results in a larger population size. Conversely, if the death rate exceeds the birth rate (a situation known as natural decrease), the population shrinks.
