Chapter 4 Flashcards
Population
A group of individuals of the same species living in the same area of interbreeding and sharing genetic information
Pandemic
Worldwide disease outbreak 1918 Spanish flu 50 million died 1999 West Nile virus 2003 SARS 2004 bird flu
Species
All individuals that are capable of interbreeding
Made up of populations
Population dynamics
The general study of population changes
5 key properties of any population
Abundance Birth rates Death rates Growth rates Age structure
Forecasting population change
P2= p1 + (B-D) + (I-E) P1= population at t1 p2= population at t2 B = # of births. D = # of deaths I = of immigrants E= # of emigrants
Growth rates
b= B/ N d = D/ N g= b-d
Doubling time
TD= 70/k (not g) k= exponential rate b = birth rate B= # of births N = total population d = death rate D = # of deaths g = growth rate TD= doubling time
Population Age Structure
The proportion of the population in each age class
Affects current and future birth rates, death rates, and growth rates
Has an impact on the environment
Has implication for current and future social and economic status
Projecting future population growth
Exponential growth and doubling time
Zero population growth, birth rate = death rate
Logistic growth curve
S shaped curve that is generated by the logistic growth equation
A small population grows rapidly
The growth rage slows down
The population eventually reaches a constant size
Logistic carrying capacity
The population size at which births equal deaths and there is no net change in population
Life expectancy
Average number of years an individual in a species can expect to live
Acute or epidemic disease
Appears rapidly in the population
Affects a comparatively large percentage of it
Declines then almost disappears only to reappear later
Chronic disease
Is always present in a population
Typically occurs in a relatively small but relatively constant presentation of the population
