Ecology Life Tables
A life table is a quantified summary of a group of individuals followed over time, referred to as a cohort. Characteristics of the population, including fecundity, mortality, and survivorship, can be quantified (Krebs, 1989). This allows a researcher to make comparisons between two populations. For example, one could compare the populations of California and Louisiana during a given time period. Then, a researcher could analyze what factors, such as habitats or resources, may have created differences between the two populations. A cemetery is a great resource for constructing a life table. One can easily gather quite a bit of data about an individual, including years of birth and death, age, and sex. Using deceased individuals also eliminates bias created by studying a live population in which certain age groups are harder to study. "Age determination is difficult for many species, and if age is not measured very carefully, the resulting life table can be very unreliable" (Begon, et. al 1996). Data may also be flawed if a large portion of younger individuals were killed due to inexperience with predation. This would cause a majority of samples to be taken from an older age category, thus bia
The number surviving to age class x was l'x. A drastic change in climate or competition for resources could potentially alter a given population. In sampling only one cemetery, we may have represented one socioeconomic class more predominantly than others. ------------------------------------------------------------------------**Bibliography**Literature CitedBegon, M. We could not successfully construct a life table for a time period in the mid-1900s because many individuals would still be alive. Mortality appeared to increase with age (Figures 1,2). Some headstones were illegible, thereby excluding the data from that person in our life table. In order to examine whether a relationship exists between the mortality rate of men and women, a Kolmogrov-Smirnov test was performed. This is probably due to either lack of medical care or an outbreak of disease. The Kolmogrov-Smirnov test gave a two-tailed statistic of 0. The number dying in each interval, x, was recorded as dx.
Common topics in this essay:
California Louisiana,
Baton Rouge,
Curves Figure,
Tables Introduction,
life table,
mortality rates,
mortality rate,
Populations Communities,
survivorship curve,
survivorship curves,
kolmogrov-smirnov test,
Townsend CR,
Krebs CJ,
women mortality,
life tables,
York York,
figure 3,
age sex,
|
Acceptance Essays
