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
Q. Why is AIDS difficult to prevent by vaccination? It is not easy to produce a vaccine against AIDS because the HIV is a highly mutant virus. In approximately every replicatio

What is the concept of universality of the genetic code? What are the exceptions to this universality? The genetic code is universal because the rules of protein codification b

Q. Write the meaning of Gestational Diabetes Mellitus? Gestational Diabetes Mellitus (GDM) is defined as glucose intolerance of any severity that has its onset or is first reco

Which of the following serves as a sensor, or as part of a sensor, that functions in a negative feedback system? A. CaSRs (Calcium-Sensing Receptors) located in the plasma memb

Asexual reproduction in fungi Fungi reproduce asexually by means of sporulation and fragmentation. Fragmentation : This is a type of asexual reproduction in fungi whi

Explain Fosamprenavir calcium It is a prodrug of amprenavir, was recently approved by the FDA for use in HAART. In patients who have not lastly been treated with a protease inh

The  extracellular   surface  of  the  plasma  membrane   is  frequently  covered  with  a protective  coat  of carbohydrate. A Sugar  residue  of this  carbohydrate  coat can  be

Q. What are changes in ST-Segment? Normal Exercise Electrocardiogram ST and J Point As the heart rate increases with exercise, a number of predictable changes occur in a

Briefly describe about Caramelization? Caramelization results from the action of heat on sugars at about 175º C. At high temperatures, sugars dehydrate, break down and polymeri

The important functional characteristics of soy protein The most important functional characteristics of soy protein concentrates are water-binding (water adsorption) capacity,