Key Issue 3

The Demographic Transition Model- Process with several stages all countries are a part of this model. There are four main stages and a fifth minor stage that only as few countries are in.

Stage 1: low growth- Most of the world's history took place in stage one of the DTM. Currently there are no countries in this stage of development. There are still a few  tribes that are in this stage of growth. The NIR is basically zero or zero population growth was achieved. After the neolithic revolution this stage continued.
Agriculutural Revolution: humans first domesticated plants and animals and settled down in settlements. Even so the human population stayed in Stage 1 until about 1750.

Stage 2: high growth- the population of an area skyrockets as the CBR greatly exeeds the CDR(CDR drops CBR stays even). After the Industrial Revolution when machinery was used to do work and the Medical Revolution where medicine was greatly inmproved the population jumped. The Medical Revolution also allowed some of the poorer countries to enter stage 2.

Stage 3: moderate growth- THe CBR drops sharply and the CDR continues its drop, the population still increases but at a slowed rate. During the 1st half of the 20th century North American countries entered this stage. Only some countires have reached this stage as much of Africa remains in the high growth area.

Stage 4: low growth- CBR equals CDR and the NIR once again reaches 0. The population is once again at zero poulation growth. THe United States and much of Westernized countries are in this stage of growth. There are a few countires that have entered the theoretical stage 5 of negative growth.

Population Pyramids- Depending on a countries stage of Demographic Transition it will have a unique structure. These pyramids show the percentage of a gender per age groups. THey are bar graphs that are normally showed in 5 year increments.

Age Distibution- The age distribution of a population can be shown on a populatiopn pyramid. THey are important because they can compare countries. the dependency ratio is the number of people to young or old to work compared to those who can, this can be shown by the age distribution on a population pyramid.

Sex Ratio- Number of males per 100 females ina population. in Europe and North America hte ratio is about 95:100. Poor countries with high childbirth mortality have a higher male percentage than female. In America the ethnic comparison can be shown by this population due to the fact that the latinos and aftrican americans like to have large families.

Countries in Different Stages of Demographic Transition- Many countries are in differetn stages of the DTM. There are no countries currently in Stage 1 but there are still countries in Stage 2. Cape Verde moved to Stage 2 in 1950, it has a high growth that fluxuates. Chile is in stage 3 meaning that it has a growing population, but its growth is slowed. The United States is in stage 4 which means it has a low almost zero population growth. A countries economy helps determine what stage it is in.

Demographic Transition and World Population- The world's population increased heavily in the twenteith century due to the fact that few countries were in Stages 1 or 4. Most countries are still in stages 2 or 3 and therefore the world population continues to rise.

Article-http://www.bized.co.uk/virtual/dc/copper/theory/th10.htm

This article is related to Key Issue 3 because it deals with how the DTM was created. The DTM was created due to the fact the trends in CBR and CDR could be seen in patterns in countries. The DTM helps to show comparison between countries NIRs.

Population is increasing at different rates in countries due to the different cultures and economic strength of countries.