Mortality and emigration decrease the population. Thus, the size of any population is the result of the relationships among these rates. Natality, mortality, immigration, and emigration rates apply to every population, including the human population. The sum of these rates makes up the growth rate of a population.
1) Agricultural Change: agricultural changes have been massive over the past 400 years. Many of these agricultural changes even at a low level free up workers from the farms. This allows industrialisation which needs lots of workers and tends to promote high birth rates. The more regular supply of food from advanced farming also promotes birth rates, as people are sure they can feed their children, and reduces famine deaths.
2) Education: Education plays a vital role in determining the levels of both birth and death rates in a country and hence the level of population growth. As education levels increase people tend to have fewer children so that they can focus their resources in improving the life chances of those few children.
3) Emancipation of women: In many rich countries women have become over time free to work when they want within their life. This is not the case in all countries in the world where many women are stuck in gender specific unpaid work such as maintaining a household and subsistence farming plots. Women are much more likely now to go to university and work for a few years before having their first child. This can result in fewer children being born per woman as fertility declines with age for women.
4) Urbanization: It has a significant impact upon population growth because it can impact upon the birth and death rates of a country. As a country becomes increasingly urbanised the birth rate tends to rise and death rates tend to fall.
5) Death rates: Often death rates are reduced before a slowdown in birth rates, causing a boom in the population size at a certain point in a country’s economic development. Death rates fall and life expectancy increased.
The invention of the electron microscope allowed them to see organelles and other structures smaller than cells. There is variation in cells, but all cells have a plasma membrane, cytoplasm, ribosomes, and DNA. These similarities show that all life on Earth has a common ancestor in the distant past
