Human Population

BiologyHuman biology


The human population is the measure of people who live in a certain region or country. The population can be recorded by the number of people living in a particular area or place (such as a city, state, or country), and by the density of the population in that area. The population is determined by a country's birth rate, death rate, immigration, emigration, and other population factors.

Human population growth is the increase in the number of humans in a population over time. The growth of the human population has been making great strides since the beginning of mankind. The total human population on Earth has increased from about 5 million 500 thousand to over 7 billion in just under 100 years. The chart below shows how our growth has progressed over time−

The world's human population is currently increasing at a rate of around 1.12% per year. This means that every year there are 1.12% more people on earth than there was the previous year. This rate is much higher for developing countries than for developed countries− according to the US Census Bureau's estimate for 2013, world annual human population growth was 1.14%, and among countries with a high Human Development Index (HDI) it was 0.43%, whereas among countries with low HDI it was 2.78%.

Why is the human population increasing?

The human population has been increasing since the beginning of civilization. The growth rate has increased due to the adoption of improved agricultural technology, and later on, industrialization. However, the rate at which the population is growing has changed over time.

Before the industrial revolution in 1750, the world population grew slowly at a rate of 0.03% per year. The global population was about 1 billion people at that time. After 1850, the world population grew faster at a rate of 0.2% per year and reached 1 billion by 1804 and 2 billion by 1927. The third billion was reached in 1959 and the fourth billion in 1974. In 1999, the world population reached 6 billion people with an average annual growth rate of 1%.

In 2011, World Population Day was celebrated on 11 July when UNFPA reported that there were 7 billion people living on Earth (World Population Clock). According to their estimates, the world population should reach 8 billion by 2030 and 9 billion by 2035 (UNFPA).

Attributes of Population

The population of a country or area is determined by two things− how many people are born in a given time period, and how many people die in that same time period. This section will discuss the attributes that make up the population of any given area.

In order to understand the population of any area, it is important to understand its vital statistics. Vital statistics include information about births, deaths, migration, and age structure. All of these combine to give us an idea of how fast the population is growing or shrinking in a given area.

When you take all of these factors into account you can come up with a population figure for any place. Population figures are always changing because they include both births and deaths. In order to get accurate numbers on births and deaths, you must use statistical data from the previous year. Population figures are used in many ways including measures of economic growth, health care costs, and education spending.

Sex ratio

The sex ratio refers to the number of males per 100 females. It can be applied to populations of humans, animals, bacteria, and other things. It is a measure of the population in which there are more males than females. This article will focus on the sex ratio in human populations.

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Sex ratio is an important aspect of population genetics and evolutionary theory. For example, if a species has twice as many male births as female ones, it's said to have a "female-biased" sex ratio; one that's biased toward males is said to be "male-bias".

Sex ratios play into evolution because populations with different sex ratios will likely have different rates of survival. For example, a male bias is believed to be more evolutionarily favorable than a female bias (since more women than men survive childbirth). On the other hand, some studies have shown that an equal sex ratio may be evolutionarily favorable− in this case, when the sexes are equally represented in the population (and therefore neither males nor females are at a reproductive disadvantage), evolution may favor any genes that increase the overall fitness of both sexes.

Mortality rate

The mortality rate is the proportion of individuals in a population who die during a given period. It is denoted by a lower case m, and the formula for calculating it is−

Mortality Rate = Number of deaths / Number of persons at risk during the time interval

The above formula can be modified to include age-specific death rates. This allows us to calculate how many individuals within each age group will die in a given time period.

For example, if we have 100 people aged 20-30 years old in our population, and 20 of them die in one year, then our mortality rate for this age group would be 2%. In other words, out of every 100 people aged 20-30 years old, 2 will die in one year.

Natality rate

The natality rate is the number of live births in a population per 1,000 people. It may also be expressed as the birth rate, which is often expressed as the number of births per 1,000 people in a year.


Population dispersion is a measure of how evenly dispersed a population is within an area. The most common type of population dispersion is by density.

Population density

The population density of an area refers to how many people live in a given area. Density can be calculated by dividing the total number of people in an area by the total area of that place. The resulting number will be denoted as people per square mile (or hectare), meaning the number of people living per square mile (or hectare).

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Types of Population Growth

Population growth is a rise in the number of individuals in a population over time. Demographers generally distinguish between 3 types of population growth−

  • Natural Growth− This is a situation where the birth rate is greater than the death rate. The number of persons born in a year exceeds the number of persons who die during the same time period.

  • Immigration− This refers to a situation where people move into a country from other countries.

  • Emigration− This refers to a situation where people leave their native country and migrate to other countries.


The human population is ever-growing and shows no signs of slowing down. With advances in technology and medicine, people are living longer and healthier lives. While this is a positive trend, it also means that the earth's resources are being strained. We must be mindful of our impact on the planet and work to ensure that our population can sustain itself into the future.


1. What is the world's human population?

The world’s human population is estimated at 7.7 billion, a figure that is expected to grow to 8.6 billion by 2030, 9.8 billion in 2050, and 11.2 billion in 2100. The average annual growth rate of the global population has declined from 1.2% in 1950-1955 to 0.1% today.

2. How many people live in each country?

China has the largest population, with 1.39 billion inhabitants, followed by India (1.34 billion), Nigeria (191 million), and the United States (324 million). China also has the highest growth rate− 0.5%, against 0.3% for India and 0.2% for Nigeria and the United States.

3. What are the major cities with high population densities?

Tokyo is the most densely populated city in the world with 38 million inhabitants per square kilometer compared with London's 8 million inhabitants per square kilometer or Paris' 5 million inhabitants per square kilometer.

4. How does population growth affect us?

Population growth affects everything from our food supply to our water supply to our ability to deal with waste and pollution. It also affects our economy, as well as the health and education of future generations. The more people there are, the more resources we need and the less available those resources become.

5. How fast is our population growing?

Population growth rates vary considerably between countries and regions. The world's average growth rate is currently 1% each year, but some countries are growing at more than twice this rate - China, for example, is currently growing at 0.5% per year and India by 0.28%.

Updated on 13-Oct-2022 11:19:47