¿Cómo CRECE la POBLACIÓN? Natalidad 👶 mortalidad ☠️ y pirámides de población 🔼
How Does Population Growth Work?
Overview of Global Population Dynamics
- The previous video discussed the continuous growth of the global population, highlighting areas with extraordinarily high population density and contrasting them with sparsely populated regions.
- A key question arises: how does population grow? Some regions have doubled or tripled their populations over centuries. The answer lies in two main factors: natality (birth rate) and mortality (death rate).
Understanding Natality and Mortality
- Natality refers to the number of births in a specific location over a certain period. To assess whether a country has a good birth rate, we calculate the birth rate by dividing the number of births in a year by the total population, then multiplying by 1,000.
- Conversely, mortality pertains to the number of deaths occurring within that same timeframe. The mortality rate is calculated similarly, indicating how many people die per 1,000 inhabitants.
Calculating Population Growth
- To determine if a population is growing or declining, subtract the mortality rate from the natality rate. Dividing this result by 10 gives us the percentage growth of that population.
- If this calculation yields a negative result, it indicates that instead of growing, the population is decreasing.
Additional Demographic Indicators
- Other demographic indicators include fertility rates (average number of children per woman), calculated as total births divided by women aged 15 to 49 years multiplied by 1,000.
- Infant mortality rates indicate how many infants die out of all born in a given year; this is crucial for understanding health challenges in less developed countries.
Life Expectancy and Its Misconceptions
- Life expectancy measures average age at death but can be misleading; for instance, an average life expectancy of 30 years may reflect high infant mortality rather than adults dying young.
- As populations develop, their demographic indicators—natality rates, mortality rates, fertility rates—change systematically rather than randomly.
The Demographic Transition Model
- This model outlines three main phases:
- Phase One: High natality and mortality lead to stagnant growth typical in underdeveloped countries or historical periods like ancient times.
- Phase Two: Improvements in living conditions reduce mortality while natality remains high; countries like China and India exemplify this phase today.
Demographic Insights Through Population Pyramids
Understanding Population Pyramids
- A population pyramid is a graphical representation that illustrates the distribution of various age groups in a specific country, divided by gender.
- The data typically ranges from ages 0 to 80 or 90 years, showing the number of individuals within each age bracket.
Shapes and Their Implications
- When a population pyramid has a triangular shape, it indicates a high number of children and young people compared to elderly individuals, suggesting high birth and death rates. This scenario is typical for countries with an ancient demographic regime.
- Countries with this progressive pyramid shape are often underdeveloped, such as those in sub-Saharan Africa, where growth rates are significant but not as high as in other regions.
Types of Population Pyramids
- Stationary Pyramid: Characterized by an adult population slightly larger than the child population; this indicates declining birth rates and reduced mortality rates. It is common in developing nations.
- Regressive Pyramid: Represents countries with low birth and death rates, leading to an aging population; typical for developed nations like Spain. This shape reflects demographic challenges associated with an older populace.
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