Nov 17 2010
Population Ecology
In class on Tuesday we learned about species populations. A population is a group of individuals of a species that live in a particular area. Populations coevolve based off of the five relationships we learned about in the previous unit (mutualism, comensalism, parasitism, predation, and competition). All populations of any species contain these five characterisitics:
1. Size: Population sizes increase, decrease, or are stable, and follow patterns
Equation: (Births + Immigration) – (Deaths + Emigration) = Change in size
2. Density: The number of individuals per unit of area
Increase in Density-
Pros: acccess to mates increases, safety increases
Cons: intraspecific competition increases, rescources decrease, predation increases, rate of infectious disease spreading increases
3. Distribution:
1-Clumped Distribution:herds, school of fish, humans(urbanization)
2-Uniformed Distribution: organisims evenly spaced
3-Random Distribution: trees (seed travel)
4. Age/Sex Stucture:
Sex Ratio-porportion of males to females
Age Structure-describes relative numbers of organisms of each age within a population
Age Structure Diagram
5. Growth Rate:
-annual growth in percentage form
-grows exponentially, yet with limits, which is why graphs have a logistic growth curve
- all populations have theoretical limit (carrying capacity)
Growth Rate Graph
Age Structure Diagram: http://images-mediawiki-sites.thefullwiki.org/08/3/8/3/25099082503828593.png
Growth Rate Graph:
http://www.cdli.ca/courses/biol2201/unit04_org01_ilo02/BI300002.gif
Good first scribe post. You will need live links to the sources of the images you borrowed. There is a little chain link icon in the editor to help you do this. Let me know if you need help.
Good fix. My only other input is that this reads more like just an outline of what went on the board. If you reread the scribe post instructions, you were to go beyond that. Think about that when you do this next semester.