Four distinct phases of demographic transition, Biology

Four Distinct Phases of Demographic Transition

Demographic transition takes place in four distinct phases.

1. Re-industrial stage in which harsh living conditions lead to high birth rates to compensate for high infant mortality and high death rates. This leads to little population growth.

2. Transitional stage which starts shortly after industrialisation begins. At this stage death rates drop as a result of increased food production and better sanitation and health care. Birth rates remain high, population grows at a high rate (2.5-3% per year) for a long period but begins to level off later as living conditions improve.

3. Industrial stage in which industrialisation is widespread. Birth rates fall and eventually approach death rates, as people after moving to cities realise that it is more to their advantage to raise small families in an expanding economy.

4. Post-industrial stage in which birth rate equals death rate thus leading to zero population growth (ZPG) Birth rate continues to fall so that the population size begins to decline slowly.

Posted Date: 1/21/2013 1:46:03 AM | Location : United States







Related Discussions:- Four distinct phases of demographic transition, Assignment Help, Ask Question on Four distinct phases of demographic transition, Get Answer, Expert's Help, Four distinct phases of demographic transition Discussions

Write discussion on Four distinct phases of demographic transition
Your posts are moderated
Related Questions
Define Metabolic utilization of carbohydrates? Following absorption, the monosaccharides enter the portal circulation and are carried to the liver. Both galactose and fructose

What is Diatoms? Bacillariophyta are commonly known as diatoms because of their unique structure. These unicellular photosynthetic organisms are composed of two overlapping glas

Define Conservation genetics and hybridization? Is the genetic integrity of European wolves threatened by hybridization along with free-ranging dogs? To ascertain the extent of

Standards of Psychiatric Nursing: By  1956, the Masters programme was extended  to two academic years. Some nurses established private practices with psychiatric patients. It

Q. What is gastrulation? How during gastrulation are the first two germ layers formed? What are these germ layers? Gastrulation is the process through which a portion of the bl

Q. What is Peri-Implant Disease? The term peri-implantitis is used to describe the boneloss around an implant. This may be induced by stress or bacteria or a combination of bot

Under which forms is the Trypanosoma cruzi found in its hosts? In the definitive hosts as well as in triatomine bugs (middle hosts) the protozoan that causes Chagas' disease ch

Meat products Meat is an important commodity in the diet of people in view of its complimentary role in balancing the diet with rich source of amino acids, vitamins and mineral

Energy Loss - Energy Flow Let us now take the second point that is the loss of some energy at each trophic level. You might recall that the second law of thermodynamics states

What are the risk factors of cataractogenesis? Risk Factors of Cataractogenesis: a. Hereditary b. Exposure to ultra violet radiation: The ultra violet radiation of 290