Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
27 Cards in this Set
- Front
- Back
|
Define:
Populations |
A group of organisms of the same species occupying a particular place at a particular time.
|
|
|
Why are populations said to be the "unit of evolution"?
|
Because evolution occurs within a population.
|
|
|
Define:
Abundance |
The number of organisms in a population.
|
|
|
In what "unit" is abundance usually expressed as?
|
Density
(# of organisms) / unit area (# of organisms) / unit volume |
|
|
Population density:
What are the 2 main factors that INCREASE population density? |
Natality
Immigration |
|
|
Population density:
What are the 2 main factors that DECREASE population density? |
Mortality
Emigration |
|
|
Define:
Natality |
Addition of new individuals by reproduction
|
|
|
True/False:
Different organisms require different techniques for determining their population density |
...TRUE!
|
|
|
What are the 2 main forms of estimating density?
|
1 - Absolute density (e.g. population has 14 individuals / km^2)
2 - Relative density (i.e. Area X has more of individual A than Area Y) |
|
|
What are 2 techniques used to get an Absolute density?
|
1 - Total count (count *every* individual in a population)
2 - Sampling methods |
|
|
Describe a sampling method (as it relates to estimating absolute density)
|
A small portion of the population is counted, and results are extrapolated to the whole.
|
|
|
Define:
Quadrat |
A sampling area of any shape or size
|
|
|
Describe how Quadrat sampling works
|
a) Form some quadrats (an area of known size)
b) Count exact number of organisms in your quadrats c) Average density of organism in quadrat is extrapolated to the whole population |
|
|
Quadrat sampling works well for what type of species?
|
stationary species (e.g. trees, invertebrates)
|
|
|
What are 3 assumptions to Quadrat sampling?
|
1 - Numbers in quadrats are counted *exactly*
2 - Area of quadrats must be known *exactly* 3 - Quadrats are representative of whole area (i.e. they were placed in a random manner) |
|
|
Describe the Peterson Index method of estimating absolute density.
|
1 - Sample of M individuals are removed from a population of size N
2 - Individuals are marked and released back into the population 3 - Sample of n individuals are captured at some point in the future. 4 - Some of those captured (m) will be marked from first sample. USE: N = Mn/m |
|
|
List the equation for the Peterson Index, and describe what each variable (4 of em) represents.
|
M/N = m/n
or N = Mn/m M = # captured and marked N = estimate of population size n = Total # captured on second run m = # out of n who are marked |
|
|
What are the 3 assumptions of the Mark-Recapture method?
|
1 - Marked and unmarked captured randomly
2 - Marked and unmarked have same mortality (i.e. bunnies are not marked by dipping in orange paint) 3 - Marks are not lost or overlooked |
|
|
What are 4 ways to estimate Relative Density?
|
1 - Captures / unit effort
2 - Scats and fecal pellets 3 - Vocalization frequency 4 - Artifacts |
|
|
Define:
Fecundity |
Fecundity ≡ Potential reproductive output
EXA: Human fecundity = 1 child / 10-11 months |
|
|
Define:
Fertility |
Fertility ≡ Actual reproductive output
EXA: Human fertility = 1 child / 15 years |
|
|
Define:
Potential longevity |
Maximum lifespan
|
|
|
Define
Actual longevity |
Mean lifespan
|
|
|
TRUE or FALSE:
Over the course of history, actual human longevity has remained constant while potential human longevity has steadily increased. |
FALSE
Potential human longevity has remained constant at around 100 years of age. Actual human longevity has steadily increased due to advances in hygiene, medicine, etc. |
|
|
Define:
Source Population |
Emigration > Immigration
|
|
|
Define
Sink Population |
Immigration > Emigration
|
|
|
What are 3 ways that populations are not composed of identical individuals?
|
1 - Individuals differ by genotype
2 - Individuals differ by sex 3 - Individuals differ by age |
