topic 4

influences of population over time

maximum reproductive rate of an organism

birth or natality,death or mortality, immigration, emigration

movement of individuals out of a population

ratio of the size population at time compared to the size of the population during some previous moment in time

r=b-d b=birth rates. d=death rates

J curve growth at an increasing rate per unit time

growth at a constant rate per unit time

dN/dr=rN

limits future growth (ex shortage of growth)

a measure of extent to which population exceeds carrying capacity of its environment

causes negative growth curve

rapid dieback in the population to a level below the carrying capacity

when a population undergoes repeated cycles of overshoots followed by crashes

population explosion followed by population dieback

1798 an essay on the principal of population (beloved human population tend to grow until they exhaust resource and crash)

growth rate changes over time s curve (sigmoidal growth rate)

adapted to employ a hig reproductive rate

longer lives, reproduce more conservatively with longer generation times, late sexual maturity,fewer offspring

quantify the number of offspring that survive over time - survive childhood, probability of death, mortality

helb back by diseases Damon's and wars so grew slowly

reaches 1 billion

reaches 3 billion

5-6 billion

within 100 years

argued human population tend to increase exponentially while food production plentiful

population ×affluence×technology

population is a symptom rather then a root cause of poverty and other social problems

believe we are approaching or surpassed earth carrying capacity

believe eliminating oppressial through social justice solve population problems

2020=72

2020=17

8

2.3

9

population pyramid determine dependency ratio

pattern of falling death rate and birth rates seen beacouse of economic condition