1 / 13

Population Curves

Population Curves. Population Growth Curve. Age- Sex Pyramids. The Population Structure of a growing Population . A reducing population. A Stable Population. Calculating Rates…. Birth Rate = Number of Births per Year x 1000

lydia
Download Presentation

Population Curves

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Population Curves

  2. Population Growth Curve

  3. Age- Sex Pyramids

  4. The Population Structure of a growing Population

  5. A reducing population

  6. A Stable Population

  7. Calculating Rates… Birth Rate = Number of Births per Year x 1000 Total Population in the same Year DeathRate = Number of Deaths per Year x 1000 Total Population in the same Year Population growth rate (%) = Population Change during the Period x 100 Population at the start of the Period

  8. The Demographic Transition Model

  9. Stage 1. Pre-industrial phase -Birth and death rates are high, population grows at a modest rate or is stable at a high level Stage 2. Transitional stage - Lowered death rate but birth rate is still high so population grows rapidly Stage 3. Industrial stage - Decline in birth rates slows population growth even though death rates are still low Stage 4. Post-industrial stage - Population grows slowly or not at all as the population is better educated and more affluent. (U.S. Canada, Europe). Population is stable at a low level, if not increased by immigrants.

  10. Survival Curves

  11. In type I survivorship, as shown by humans and elephants, the young have a high probability of survival. The probability of survival decreases with age; that is, deaths are concentrated later in life. In type III survivorship, the probability of death is greatest early in life, ad those that avoid early death have a high probability of survival. This is characteristic of many fish and oysters. In type II survivorship, which is intermediate between types I and III, the probability of survival does not change with age. This survivorship is rare, as it results essentially from random events that cause death, but is true for some lizards.

  12. To work out life expectancy… % of population alive Look at the age when just 50% of the population are alive

More Related