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BIO 320 Test #2
Fundamentals of Ecology
53
Other
Undergraduate 2
02/28/2013

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Cards

Term
herbicide resistance case: Johnsongrass
Definition

glysophate ("Round-Up") is most used herbicide in the world - cuts off amino acid synthesis in plants

 

GM crops are resistant to Round Up, but weeds aren't 

 

after a few years, glysophate is no longer as effective at killing Johnsongrass - those previously exopsed to glysophate were favored to those not -- RESISTANCE

Term
Georges Cuvier
Definition
fossils, strata, and catastrophism
Term
Charles Lyell
Definition
time, gradualism, uniformitarianism
Term
Jean Baptiste Lamarck
Definition
use and disuse of body parts to cope with the environment cause them to become larger or smaller; acquired characteristics can be inherited
Term
At the time of his voyage on the Beagle, what did Charles Darwin know about natural populations?
Definition

1) populations produce many more offspring than survive

2) a population's biotic potential is rarely reached because of a lack of resources

3) members of a population differ from each other in many ways

Term
7 components of Darwin's Theory of Evolution
Definition

1. All life EVOLVED from one relatively simple kind of organism

2. Every species arose from a species that preceded it in time.

3. Evolutionary changes occur over long periods of time
4. Each species originated in a single area.
5. Over long periods of time, more related groups arose by a continuation of the same evolutionary processes.

6. greater similarity = closer relationship and more recent common ancestry

7.Elimination of old kinds is due to competition with new kinds or environmental change.

NATURAL SELECTION 

Term
Darwin's Theory of Natural Selection (7 parts)
Definition

1. Populations have the potential to increase rapidly in number from one generation to the next.

2. in the short run, populaton size remains fairly constant because the environment limits population growth.

3. Individuals within populations are distinct.

4. Struggle for survival = those with favorable variations survive to produce more offspring

5. Some variations are heritable

6. environments have been changing throughout geologic time

7. natural selection causes accumulation of favorable variations and elimination of unfavorable ones

Term
Three key features of evolution by natural selection
Definition

1. Variation

2. Heritability

3. Differential fitness

Term
Clausen, Keck and, Hiesey study on plants from different elevation gradients showed that
Definition

plants from diverse populations responded differently when grown in the same environment

 

there is a genetic basis to variation in traits from region to region

Term
Gregor Mendel discovered that
Definition

characteristics pass from parent to offspring in packets called genes, which exist in alternate forms known as alleles and that some alleles prevent the expression of others

 

inheritance 

Term
Hardy Weinberg Principle
Definition

 In a population:

- mating at random

- in the absence of evolutionary forces

allele frequenceies remain constant.

 

Term
Four Testable Postulates of the theory of evolution by natural selection
Definition

1. Individuals within same species are variable

2. Some variations passed to offspring (heritable)

3. In every generation, more offspring are produced than survive (struggle for survival) to reproduce

4. the fittest survive to reproduce (survival of the fittest)

Term
In Darwin's study of finches on the Galapagos Islands, he found that the finches had
Definition
evolved to have deeper beaks through rapid evolution as the result of a recent drought.
Term
Carroll and Boyd 1992
Definition
done on the soapberry bug and determined that soapberry bugs living on host plants with larger fruits have longer beaks
Term
Natural selection acts on ____ but its consequences occur in ____.
Definition

individuals

populations

Term
____ acts on phenotypes, but ____ consists of changes in allele frequencies.
Definition

natural selection

evolution

Term
Does natural selection actively benefit the species?
Definition
No, natural selection acts on the individual without regard for the betterment of the species.
Term
genetic drift
Definition
the process by which the frequency of alleles with the same fitness changes in a population
Term
founder effect
Definition
genetic drift in a new colony
Term
Why is lower genetic variation a problem for small populations?
Definition
Because they are less likely to evolve and adapt to changes
Term
Three types of Natural Selection & Definitions
Definition

1. Stabilizing - selection favors individuals close to the mean

2. Directional - selection favors individuals in one direction over another

3. Disruptive - selection favors individuals in both extremes

Term
ecosystem
Definition
piece of earth any size that contains biotic and abiotic elements, boundary, and interaction
Term
What is "urbanization" and how is it changing globally?
Definition

urbanization is the movement of people to more condensed living, like in cities

 

it is currently increasing rapidly around the world

Term

McDonnell and Pickett 

the urban-rural gradient concept

Definition

-based on the gradient paradigm in ecology (ordered environmental variation explains variation in ecological structure and function)

- argued for study of basic ecological patterns and processes, multi-scaled

- argued for inclusion of humans in ecological study

 

Term
How to study urban populations: "four legs of the table"
Definition

-long term observation

- experiments

- data discovery, synthesis, and modeling

- comparative ecosystem ecology

Term
Urbanization effects on hydrogeomorphology
Definition

- large scale diversion

- channeling of streams

- disruption of connectivity

- increase in impervious surface cover

- in the desert, localized increases in pervious cover (green space)

Term
Research shows that ___ are effective in removing nitrogen while ____ are not.
Definition

floodplains

lakes and stream segments

Term
Urban environments are characterized by (low/high) species diversity.
Definition
low
Term
the basic reproductive rate, R0
Definition

the average number of secondary cases a typical infectious person will cause in a completely susceptible population

measures the intrinsic potential for an infectious agent to spread

Term
the average number of cases a person will generate depends on 4 factors
Definition

1. the number of contacts made (c)

2. the probability of infection given contact (p)

3. duration of incfectiousness (L)

4. the proportion of contacts who are susceptible (S)

Term
If everyone in a population is susceptible, then

R0= ____
Definition
R0= c x p x L
Term
If R< 1, then
Definition

infection cannot invade a population 

implications: infection-control mechanisms unnecessary

Term
If R0 > 1, then
Definition

on average, the pathogen will invade that population

 

implications: control measure necessary to prevent/ delay an epidemic

Term
R(t) - the effective reproduction number
Definition

0 at initial invasion

1 at peak of epidemic

 

number of susceptibles decreases through recovery or death -- eventually insufficient to carry epidemic, dies out

Term
If a disease is endemic, R will be approximately
Definition
1
Term

f = fraction of the population that must be vaccinated

f > ____

Definition
f > 1 - (1/R0)
Term
When land is fragmented, smaller fragments have (higher/lower) species diversity than larger fragments.
Definition
lower
Term
When generations do not overlap, growth can be modeled ____.
Definition
geometrically
Term
If growth occurs continuously (generations overlap), then growth can be modeled _____.
Definition
exponentially
Term
What prevents continued exponenetial growth?
Definition

-- external (p-independent factors)

-- self- regulation (p-dependent factors)

-- interactions with other species (p-dependent factors)

Term
environmental stochasticity
Definition
random variability in environmental factors which cause fluctuations in r (population growth rate)
Term
demographic stochasticity
Definition
random variability in birth or death rates
Term
the logistic growth model assumes: (3)
Definition

1. birth/death and density influences growth instantaneously

2. all individuals genetically the same

3. all equals equal in terms of birth and death - age doesn't matter

Term
Human population densities are highest in the ____ regions of all continents.
Definition
coastal
Term
For _____ organisms, individuals in a respresentative habitat can be counted and the numbers extrapolated to the whole ecosystem.
Definition
sedentary
Term
the age structure of a group refers to
Definition
the distribution of individuals across all age groups
Term
age structure affects population growth because
Definition
reproductive capacity varies with age
Term
static life table
Definition

inexact

1. record age at death of individuals over a short time interval (estimation bias problems)

2. estimate survival using the proportion of individuals in each age class. survival estimates assume a stable population (not declining or growing)

Term
cohort ("dynamic") life table
Definition

often best

- identify individuals born at same time and keep records from birth. requires recording how long each individual lives (intensive)

Term
static life tables show ___ but not ____
Definition

survivorship and mortality

if population is increasing or decreasing or remaining the same

Term
constant survivorship
Definition
relatively constant rates of survival or death rates with age
Term
"concave" survivorship
Definition
high death rates of young individuals with low death rates later in life
Term
Type I, Type II, and Type III Survivorship
Definition

I - High overall survivorship

II - constant risk of mortality

III - low juvenile survivorship

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