Q.Enlist and explain the important characteristics of a population.

Step 1. Size and Density (N). A population's most basic characteristics are its size (total number of individuals) and density (individuals per unit space, in a given time). While total count is usually the most workable measure, in some situations -- like comparing a huge number of tiny termites against their few predators -- biomass or relative/indirect measures (catch-per-trap, pug-mark census) give a more meaningful picture of population size. Step 2. Natality. The birth rate of the population, and generally its biggest driver of growth. Crude birth rate (births per 1000 individuals per year) is used for overall population size, while specific birth rate is calculated relative to a criterion such as age. Absolute natality (births under ideal, unconstrained conditions) is always at least as large as realized natality (births once real environmental pressures apply). Step 3. Mortality. The death rate of the population, typically expressed as deaths per 1000 individuals per year. Absolute mortality (deaths under ideal conditions) is always less than or equal to realized mortality (deaths once environmental pressures apply). Step 4. Sex ratio. The ratio of individuals of one sex to individuals of the other; it both influences and is influenced by the population's birth, death, immigration and emigration rates, with a 1:1 ratio generally being the most common evolutionarily stable strategy (ESS) in nature. Step 5. Age distribution / Age pyramid. A po …

Enumerate each named population attribute from the chapter in turn, defining it and …

• Listing size/density alone and treating it as the population's only meaningful characteristic, while omitting natality, mortality, sex ratio and age structure. …