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1. Define the following terms:-Mr. V approved
a. Population—a localized group of individuals that belong to the same biological species (that are capable of interbreeding and producing fertile offspring)

b. Density—the number of individuals per unit area or volume

c. Dispersion—the distribution of individuals within geographic population boundaries

d. Mark-recapture method-- a sampling technique used to estimate wildlife populations.

e. Immigration-- The influx of new individuals from other areas

f. Emigration— The movement of individuals out a certain population

g. Territoriality—A behavior in which an animal defends a bounded physical space against encroachment of other individuals, usually of its own space. It may involve direct aggression or indirect mechanisms such as scent marking or singing.
-- Brian N
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2. What are the three patterns of dispersion and what conclusions can you draw from these patterns? -Mr. V approved
Clumped Dispersion—Are dispersions that the individuals aggregate in patches through out the surrounding areas. They may be influenced by behavior, mating, and resource availability. Ex. Wolves live in clusters so that hunting is easier for them.

Uniform Dispersion—They are dispersions that the individuals are evenly distributed. This could be influenced by social interactions such as territoriality. Ex. King penguins experience uniform dispersion when they are caring for their eggs making sure that they are not too close to their neighbors.

Random Dispersion—It is the type of dispersion in which the position of each individual is independent to the other individuals. Ex. Dandelions in a field, this is random because of the may its seeds are distributed (carried by the wind; it varies). -- Brian N



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Conclusions that can be drawn from these three types of dispersal are that all of the species, no matter what type of dispersal, populate the areas which are best for their ability to pass on their genes. Also there is dispersal due to territoriality. --Jordan W.







3. Define the following terms: -Mr. V approved

a. Demography-the study of vital statistics of populations and how they change over time

b. Life tables-age-specific summaries of the survival pattern of a population


c. Survivorship curves-a plot of the proportion or numbers in a cohort still alive at each age


d. Reproductive table-fertility schedule


e. Life history-traits that affect an organism’s schedule of reproduction and survival.
i. There are three basic variables
1. When reproduction begins
2. How often the organism reproduces
3. How many offspring are produced during each reproductive episode






Laura C.


4. post diagrams of the three different survivorship curves – give an example of an animal that fits the curve and an explanation of why they fit the curve. -Mr. V approved
Survive.gif Refer to Diagram to the right

Type 1.
Elephants are this type of curve. They fit this curve because a large amount of them live during the early and middle years of their life, but as they get to a very old age the number of survivors drops rapidly.

Type 2
Rodents such as mice have this type of curve. This fits the curve because there is a constant rate of death as they age.

Type 3.
Long-lived plants have this type of curve. They fit this curve because they produce large amounts of offspring but provide no care for them. Most of the young population dies off right away and then the survivors, what is left of them, last a while




Zack B.



5. Compare and contrast semelparity and iteroparity – give advantages of each as they apply to an example organism – focus on the adaptive benefit of the life history. Are there any disadvantages? This is a core concept. -Mr. V approved


Semelparity is also known as big-bang reproduction. This is when an animals or plant gets one chance to reproduce. An agave will produce a large flowering stalk. It won’t release its seeds until the conditions are right. After it does this it dies. Producing many offspring like this is most common in unpredictable and the survival rate of offspring is low.

external image sturgeon.jpg

Sturgeon
(note - sturgeon are an r-selection species b/c of low parental care. Adults can live past 60 years)


Iteroparity or repeated reproduction is when an organism will annually reproduce a limited amount of offspring. This is most common in environments that are predictable and where competition is relatively intense. This will give way for a few well off individuals to reproduce.


external image mr_baby_elephant.jpg
Elephant
Martin A.








6. What is zero population growth? -Mr. V approved
A period of stability in population size, when the per capita birth rate and death rate are equal.
- Shayne Huttick



7. What is exponential population growth? What kind of graph would you expect to see? -Mr. V approved
If a population has a constant birth rate through time and is never limited by food or disease, it has what is known as exponential population growth. With exponential growth the birth rate alone controls how fast or slow the population grows.
The graph expected would be an increasing trend:

external image expgrowth.gif
-Amanda P.


8. Read section 52.4 slowly – we are not focusing on all of the math but the concepts – explain the logistical population growth model. How does “K” fit the population growth model?


-Mr. V says don't be afraid of explaining math concepts. Be very afraid!



9. Compare and contrast r and k selection – this is a key concept – do some additional research and try to come up with at least six points of comparison. -Mr. V approved

K-selection is selection for life history traits that are sensitive to a population density. This is also called density-dependent selection. R-selection is selection for life history traits that that maximize reproductive success in un-crowded environments, or low densities. This is also called density-independent selection. K-selection maximizes population size and operated in populations living at a density near the limit imposed by their resources. R-selection, however, maximizes the rate of increase and occurs in environments in which population densities fluctuate well below carrying capacity or individuals are likely to face little competition.

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K-Selection
R-Selection
Populations with low reproductive rates
Experience rapid population growth
Selection for life history traits that are sensitive to population density
Selection for life history traits that maximize reproductive success in un-crowded environments with low densities
Maximizes population size at carrying capacity
Maximizes rate of increase in fluctuating populations
Competition within population
Little or no competition within population
Population grows slow, reproduces slowly, and lives much longer
Population grows fast, reproduces quickly, and die quickly
Example= humans
Example=bacteria

-Corinne DJ



10. What is the difference between density-dependent and density-independent factors as a general term? -Mr. V says approved :)

Density independent describes a birth or death rate that does not change with population density. Therefore, other physical factors in the environments could possibly cause mortality rates to increase. Examples of these factors include floods, droughts, earthquakes, and carious other natural disasters and weather conditions. These factors are all a result of nature, which cannot be controlled or determined by the size of the population.

In contrast, density dependent describes a death rate that rises as population density rises, or birth rate that falls with rising density. This is true when reproduction declines as population density increases. Examples of this include food supplies, which can run low when a population approaches its carrying capacity, waste products that build up, and population-crowded diseases.


-Corinne Dj




11. Describe six density-dependent factors in population regulation. -Mr. V approved

Six density-dependent factors in population regulation are competition for resources (increasing population density intensifies competition for nutrients and resources, resulting in lower birth rates), territoriality (limits density; territory becomes the resource for which individuals compete), health (disease is more easily transmitted in dense populations), predation (predators capture more food as prey population increases), toxic wastes (organisms, such as yeast, produce ethanol when in abundance can limit population size), and intrinsic factors (physiological factors sometimes regulate population size).

King Penguins fight agressively with each other to defend their personal space (Territoriality).
manchots.jpg

Dan S.






12. What is population dynamics? -Mr. V says needs revision (incorrect)

Population Dynamics is the study of how the environment causes the change of the species living in the environment. It follows a species from birth to death, and follows how the environment caused the species to survive and die. A simple way to record the data of population dynamics would be with an abiotic and a biotic category. The abiotic category would consist of things like temperature, soil, and the weather. The biotic category would consist of things like death rate, mutation, and migration.

Jim R



13. What kinds of information do age structure pyramids provide and what inferences can be made from these? -Mr. V approved
Age structure pyramids present the relative number of individuals from a certain area of each age. Possible population trends can be predicted from these pyramids. For example, if the younger ages have a heavier representation, then the population will likely increase when they reach reproductive age, but if the older ages have a larger representation then the population will like diminish. For areas that have nearly even representation, the population will most likely stay fairly even. Kim K. Red Team

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Emily A. Red Team

Age structure pyramids can predict a population’s growth trend as well as its social conditions. For example, if there is an overwhelming amount of a certain age group compared to the others, it could easily throw off the social balance in a population and possibly cause chaos and unrest. --Jackie H. red team






14. How can an ecological footprint be useful?-Mr. V approved

Ecological footprints can be very useful in determining how much of the resources provided by the area a population can use before using them up completely which helps determine possible population trends if the resources seem likely to be used up or if they are plentiful. Kim K. Red Team
ecological_footprint.jpg
Emily A. Red Team

Ecological footprints can be useful when helping to predict the land and water area needed by each nation to provide all of the resources that it consumes and also absorb all of the waste it generates. –Jackie H. red team

Ecological footprints are also useful for addressing international disparities as countries plan for and balance resource use, development, and conservation efforts. For example, most products and goods used in America are made at tremendous environmental cost to developing nations (think air and water pollution in China, India, and Africa). If we dramatically reduced our consumption of raw materials we would reduce our impact on those resources, but we would also compromise those developing economies. To meet both goals we could shift our consumption to goods that are manufactured from recycled or sustainable products through low impact technologies (and perhaps pay a little bit more)
-Mr. Vinogradov