| POPULATION!!!!!! |
| a SUMMARY |
| 1. What is the difference between arithmetic gr0wth and exponential growth, and which one does an uncontrolled population exhibit!?!?!? |
| Exponential growth - a constant rate of increase per unit of time. it is called exponential beacsue the rate of increase can be expressed as a constant fraction or exponent by whcih the existing opualtion is multiplied. |
| arithmetic growth - increases at a constant AMOUNT per unit of time |
| obviously, an uncontrolled one exhibits exponential |
| 2. What is the definiton of biotic potential and what are the two factors that most directly influence biotic potential of a population? (p130) |
| "We call the maximum reproductive rate of an organism its biotic potential." |
| - Reproductive rate: number of offspring per birth or produced by an organism |
| -Recruitment: number of offspring that survive to reproduce |
| bold terms |
| 3. Be able to define the difference between Malthusian and Logistic Growth, and know the type of population oscilattions that each may cause. (p130) |
| Malthusian Growth(irruptive) |
| Logistic Growth |
| - large number of young, low recruitment |
| - small number of young, high recruitment |
| - overshoots and diebacks |
| - environmental resistance |
| "Populations may go through repeated oscillating cycles and catastrophic crashes" |
| "...regulated by both internal and external factors so that they come into equilibrium with their environmental resources." |
| 5. What are some of the factors that act to maximize a population's biotic potential and what are some of the environmental resistance factors that push back agaisnt the full biotic potential to keep the population in balance? |
| J - Curve - theoritcal unlimited growth S - Curve - popualtion ggrowth and stabilization in response to environmental resistance overshoot - pop. exceeds carrying capacity of environ. dieback - population crash carrying capacity - duh environmental resistance - factors that tend to reduce pop. growth population balance - biotic factors: predators, competiton, biodiversity population imbalance - ecosystem invasion, removal of environmental resistance fertility rate -number of offspring produced total fertility rate - avg number of offspring produced over life of indiv. replacement fertili ty - fertility rate needed to maintain pop. size constant population profile - age/sex/size distribution determined by birth/death rate population density - number of indivuals per unit area critical number - minimum number of indiviuals needed to sustain pop. optimum - ideal pop size |
| 6. What is population density, and what are the minimum, maximum and best levels it can exist in with stability? What happens to the population if density goes below the minimum or above the maximum? |
| 12. Know the three types of populations seen in the age structure diagrams. |
| 13. The recent increase in human popualtion is mostly due to what two things |
| What is the current population on Earth, what is it's doubling time, and what is its growth rate. |
| 16. Be able to describe the four phases of a demographic transition and label them on a diagram. Know what labels to put on the axes of a demographic transition diagram. |
| -reproductive rate -ability to migrate or disperse to similar habitiats -ability to adapt and invade new habitats - defnese mechanisms - resistance to adverse conditions and disease |
| -availability(lack) of food or nutrients -lack of water -lack of suitable habitat -adverse climatic conditions -predators and parasites -competitions -disease |
| population density: number of individuals per unit area |
| critical number: minimum number of individuals needed to sustain a population |
| carrying capacity: maximum number of individual that can be sustained by a system |
| optimum: ideal population size |
| Some populations depend upon others, and a low population might mean no food for another species, and a high pop. might mean over competiton |
| reduction in disease and transmission(sanitation, vaccines) increase in nutrition |
| 6.3 billion 42 years |
| PHASE I : "primitive stability" (high death, high birth) PHASE 2 : Decreasing death rate - mostly by decreasing mortality of population PHASE 3: Decreasing birth rate - through reduction of fertility rate PHASE 4: "Modern" stability (low death, low birth) |
| expanding pop(younger) stable pop(middle/lower) diminishing (middle/upper) |
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| there are two "Strategies" of pop. growth, malthusian and logistic. Malthusian and Logistic. Malthusian has high amount of offpsring with a low amount of recruitment(offspring survival to reproduce) and logistic invests more in a smalelr number of offspring. Environmental resistance keeps reduces the rate at which a population increases. Population density is the amount of indiviuals living in an area. A balance is important since a population over the maximum can cause depletion of resources and a minimum can affect other populations dependent on them. A demographic shifts from primitive stability (high death high birth) to reduced death rate, to reduced birth rate, and then to modern stability (low death, low birth) N = No X e^kt <----- pop. growth let n = pop No = current pop k = rate t = time T = .7/k <----doubling rate |