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Ecology
Crabtree final
96
Biology
Undergraduate 4
08/10/2009

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Cards

Term
What is a population? Why is the study of them so important to evolutionary ecology?
Definition
1. a group of individuals of
the same species in a given area”
2. Because it allows us see how the same species differentiate from each other based on their isolation
Term
What are the three patterns for the dispersion of individuals in space? What might lead to these patterns?
Definition
Random, Clumped, Uniform. Resources such as food, mates, and shelter are what might lead to these various patterns.
Term
Why is genetic variability for the population?
Definition
Because it allows for different genetic pools which in turn lead to differential survival which is how a population evolves and survives.
Term
How can we estimate the population size in a given area (if you catch something)? Know the simple formula
Definition
Mark and Recapture:x/n = M/N
Lecture 7 slide 13
Term
Know one of three ways to evaluate age structure and how the information may be used to derive predictions about the population.
Definition
Follow a cohort of individuals through time and measure each individual at each age class.
Term
Be able to describe at least three types of information we can derive from life tables.
Definition
Life Expectancy, Mortality Rate, Survivorship.
Term
Know the three curves for survivorship. What does each suggest? Know examples of each.
Definition
Type I: High mortality rate at later age class
Type II: Same mortality rate at any age
Type III: Highest mortality rate at youngest age
Examples: Type 1 Humans. Type 2 Coral.. Type 3: Plants.
Term
What is r in words and mathematically?
Definition
R is the birth rate minus the death rate and it is the rate of increase
Term
Provide the equation for exponential growth rate dN/dt. Graph this equation. Is this realistic? Who was malthus?
Definition
dN/dt = rN. Looks like a parabola going off to infinite population. Malthus was a man that said this was not realistic because there would be a struggle for resources
Term

what is apparent competition?

Definition

A situation in which two or more species negatively affect one another indirectly through their interaction with a common predator.

 

 

Term
Good examples of competition?
Definition

In agriculture, cultivation methods are designed to reduce competition. For example, a crop of wheat is sown at a density that minimizes competition within the same species. The plants are grown far enough apart to reduce competition between the roots of neighboring wheat plants for soil mineral nutrients. The spraying of the ground to kill weeds reduces competition between the wheat and weed plants. Some weeds would grow taller than the wheat and deprive it of light.

 

 

Term

What is resource partitioning and how does this relate to the realized niche?

Definition

Resource partitioning is when two species partition [divide] a resource based on behavioral or morphological variation.  In this way, one species does not out-compete the other and coexistence is obtained through the differentiation of their realized ecological niches.

 

Term
what is character competition?
Definition

The divergence in the characteristics of two otherwise similar species where their ranges overlap caused by the selective effects of competition between the species in the area of overlap.

An example would be ground finches of the Galapagos Islands species.  The finches usually have beaks of different sizes, indicating the different ranges of preferred food size.  When the two species Geospiza fortis and G. fuliginosa occurred on large islands together, they could be distinguished unequivocally by beak size. When either one occurred by itself on a smaller island, however, the beak size was intermediate in size relative to when the two co-occurred.

Term

Be able to interpret the Type III functional response and specifically describe what is happening at the low prey densities.

Definition

At lowest prey densities predators with type III consume very low #’s of prey; highest consumption is at intermediate prey densities.  Type III predator response is depressed at low prey density because of low hunting efficiency or absence of a search image. 

 

Several factors lead to decreased predator response at lower prey densities (1) a heterogenous habitat may afford limited number of hiding places which protect larger proportion of prey at lower densities (2) lack of reinforcement of learned searching behavior due to low rates of prey encounters (3) switching to alternative food sources when prey are scarce

 

Term

What is meant by coupled oscillations?  Why do we often see oscillations of predator and prey populations out of sync? 

Definition

Coupled oscillations occur when predators and prey fluctuate in closely linked cycles.  Oscillations are often out of sync due to environmental or biological factors.  E.g. environmental variability, habitat disturbance 

Term

Consider example of predator/prey, parasite/host, parasitoid/host, or herbivore/plant.  Describe co-evolutionary changes in both members of the interacting pair in terms of physiological, behavioral and morphological types of adaptations.  

Definition

E.g. Yucca moth and yucca flower

-Moth enters yucca flower and deposits 1-5 eggs in ovary, scrapes pollen off anthers in the flower and rolls it into small ball, flies to another plant, enters a flower and places pollen ball onto stigma of flower before laying another batch of eggs, eggs hatch, larvae burrow into ovary and feed on developing seeds. 

 

Moth larvae can grow nowhere else and yucca has no other pollinator.  Both have specialized traits in respect to each other:  yucca flower has sticky pollen that can easily be formed into ball for moth to carry, stigma is specially modified as receptacle to receive pollen; moths visit only one species of yucca, mate within flowers, lay eggs in ovary, exhibit restraint in number of eggs laid per flower, have modified mouthparts and behaviors to obtain and carry pollen.

 

Term

Aposematic coloration

Definition

conspicuous patterns of colors adopted by noxious organisms to advertise their unpalatability or dangerousness to potential predators

 

Term

Know the three types of mutualistic relationships, the general benefits to the involved species and specific examples.

Definition

Trophic mutualism: involves partners specialized in complimentary ways to obtain energy and nutrients from each other.  E.g. symbiotic associations of  Rhizobium bacteria and plant roots to form nitrogen-fixing nodules.  Each partner supplies a limited nutrient or energy that the other cannot obtain for itself.  Rhizobium  can assimilate molecular nitrogen from the soil, but requires carbohydrates supplied by a plant for energy to do this.

 

Defensive mutualism: invovlves species that receive food or shelter from their mutualistic partners in return for defending those partners against herbivores, predators or parasites. E.g. in marine systems specialized fishes and shrimps clean parasites from the skin and gills of other species of fish.  These cleaners benefit from food value.; fish are unburdened of some of their parasites. 

 

Dispersive Mutualism: involves animals that transport pollen between flowers in return for rewards such as nectar or that disperse seeds to suitable habitats as they eat the nutritional fruits that contain the seeds. E.g. cape region of South Africa foraging ants with plants (family Proteaceae).  Ants pick up seeds and transport them to underground nests where they eat the fleshy structures inside.  The seeds which ants cannot eat are discarded in underground chambers or refuse heaps.

 

Term

Why do species cheat when it comes to receiving benefits?

Definition

The natural tension between partners in mutualism can lead to cheating in.  There is inherent conflict between participants that stems from dependency of the relationship.  In order for one of the participants to increase its fitness, it must do so at the expense of other participant

Term

What is commensalism? Provide example and describe effects on the interacting species.

Definition

a relationship between two species where one species derives benefit from the relationship and the second species is unaffected by it.  (+/0 relationship)

 

E.g. the anemonefish lives among the tentacles of an anemone and is protected from potential predators not immune to the sting of the anemone.  The anemonefish is protected from the sting of the anemone tentacles by a susbstance contaioned in the mucous on its skin.  Anemone does not sting fish

Term

What is ammensalism? Provide example and describe effects on the interacting species.

Definition

Ammensalism : occurs when one species hurts another, but does not benefit from this interaction. (-/0 relationship)

 

E.g. as wild pigs forage they often disturb the upper layer of soil and many organisms may be taken from their burrows and exposed to predation by the action of the pigs.  The harm that the burrowers suffer does not improve the pig’s situation at all

Term

Be able to define the concept of community

Definition

An association of interacting populations usually defined by the nature of their interaction or by the place in which they live. E.g. Sagebrush community, pond community.  Community structure and function are manifestations of a complex array of interactions directly or indirectly tying all members of a community together into intricate web

Term

Be able to label a curve and note the type of functional response and what that line is telling us. (Type I,II,III) 

Definition

See Fig 23-12.

Term
What is meant by connectance in food web anayses? Can any generalizations be made?
Definition
connectance- shows the flow of nutrients and energy fro trophic m 1 level to the next.
Generalizations
-# of intesnse links we find is 2
-proportion of organisms @ each trophic level is generally constant between webs
Term
What is meant by Bottom up proposal of community structure?
Definition
-the thought that primary producers establish and define the stability of the system (doesn't work for all systems)
Term
What is meant by top down model to describe community stability?
Definition
That a keystone species has the greatest influence on the community...like a tropic cascade (ex:seastar)
Term
What is meant by ecological diversity?
Definition
The complexity, jobs, or relationships we see in a given habitat
Term
How can we compare diversities among communities? How can we compare similarities?
Definition
Differences-Using potting techniques indices such as simpson or shannon weimer..
similarities- coefficient of similarities
Term
What is a climax community?
Definition
A community stable in species composition yet still dynamic (old tree grows and clears light for its same species to grow). To get to climax community then go through seres with weedy species preparing for future community. Ex: old growth forest
Term
Why do we employ diversity indices to compare communities rather than just species richness? Give an example
Definition
You should look at not only richness but abundance of organisms in each group.
ex: one community may have a lot of species where the other has a lot of populations
Term
What is the equilibrium hypothesis of species richness? What are the factors?
Definition
It a model that subjects that in a stable community the proportion of extinction's equal to the new colonizations.
-disturbance hypothesis: the smaller the area is the more likely a population is to be whipped out by a new species
-habitat diversity-the larger amount of area the larger amount of habitats in that area
-passive sampling-larger areas are easier for colonizers to inhabit
Term
Be able to illustrate graphically the expectation of a species are a plot...what is the relationship
Definition
As the total number of individuals increased the number of species will level off showing you have sampled most species in environment.
Term
List and describe two reasons sexual reproduction may be favored over asexual.
Definition
-genetic variabbility of offspring=mixing new combinations of traits by random arrangement of chromosomes
-allows for editing out mutations- only the strong organisms sexual reproduce so you edit out the bad mutations
Term
What are the cost of sexual reproduction
Definition
-Cost of shanning compositons (only pass 1/2 genes)
-Cost of Meiosis (breaks up favorable combinations)
-Cost of Males (they suck!..lol)
Term
What is the Red Queen Hypothesis? How does is related with environmental stability and sexual and asexual reproduction.
Definition
Red Queen is a model that suggests the need for sexual reproduction is a response to changes and interactions with other organisms (symbiotic pressures). As their environment rapidly changes then they needs to change quickly and sexual reproduction would be favored.
Term
What is sexual selection? Distinguish between interselection and intrasexual selection
Definition
The choosing of mates for fertilization.
interselection-selection between males and females (courtship, physical act, allowing fertilization to occur)
Intrasexual- individual compoitiion within own sex to be able to mate (ex: male deers fight)
Term
What is Runaway Selection? What does this lead to in a species?
Definition
Runaway selection is a theory that helps reconcile the difference in matting behaviors and what would be selected for in natural selection.
-Females will choose mates with elaborate characheristics and pass that choosiness down to their offspring (creates + feedback system)
-This leads to larger more elaborate characteristics being present in population until so big predator eat them
Term
What is the Handicap principle?
Definition
The handicap principle says individuals with large features selected by choosey mating makes larger charaterists popular ,but would also be more likely to be seen by predators. Those individuals with large characteristics who can still survive must be better adapted.
Term
Which sex is typically more choosey? why?
Definition
females because they spend more energy from gamete production to raising young.
Term
What is the significance of courtship or nuptial feeding?
Definition
-it may serve as courtship
-it will keep the females busy (not mating with anyone else)
-some of the things get incorporated into the egg or her body
ex: birds
Term
What is sperm competition?
Definition
Its an intrasexual selection process which sperm race to egg (usually last sperm are most probable to fertilize)
Term
What types of activities are typically at the heart of aggression and reproduction?
Definition
-fighting, displays...etc
things that lead to compete for territories, access to resources, and mates....may all cause by an incrase in limbic region which control sex, feeding behaviors, and aggression
Term
What is the Bruce Effect?
Definition
when a pregnant female aborts a baby when a new male is around. (its saves energy if infanticide would occur anyway)
Term
What is monoecious vs gonochorism
Definition
monoecious (hermaphrodites)- organisms with both male and female structures...remember 2 types ex: frog, fish, coral
gonochorism- individuals with one sex or the other ex: most humans :)
Term
1+1 = ?
Definition
3
Term
What are some benefits of being a hermaphrodite?
Definition
You can made with whomever from your species that you come across (good in earthworms)
Term
Why might it be advantageous to be a sequential hermaphrodite?
Definition
You can physically use body size to aid in reproduction...change sexuality as you grow
Term
How could one cheat if they were a simultaneous hermaphrodite?
Definition
Just produce sperm which cost less energy
Term
What is haplodiploidy? How is this dichotomy produced?
Definition
males-helpoid
females-diploid....they can choose weather to fertilize gamete thus choosing male or female progeny
Term
What is promiscuity? What circumstances would it be favored in?
Definition
When a male mates with many females...situations were female can do something male cannon (breast feeding) or when men have territories women want to mate in (ex...fish)
Term
What is prolgyny? What circumstances is it favored?
Definition
One male mates all the females in a group...this occurs when male offers defense to females in his territory
Term
What is monogamy? When is it favored?
Definition
The ongoing relation of two....arises in situations where man can make a large contribution to child.
Term
What is polyandry? What circumstances favor it?
Definition
when a single female enters into durable pair bond with more than one male...favors situations where men are vieing for right to reproduce next
Term
What is the parent/offspring conflict? What are the opposing selective forces?
Definition
When the selfish accumulation of resources by one offspring reduces the overall reproductive success of the parents.
by staying the parents are enhansing chance of survival for kin, but cost by decreasing the number of future offspring.
Term
Why might siblicide be of selective value to a parent? why not have just one?
Definition
It would be good because it has the best equipt child survive and it provides insurance incase one dies of natural causes young. Although there isn't a reason why they wouldn't just have one.
Term
How might brood parasitism evolve? What are the costs/benifits?
Definition
Term
What are the basic components of all optimality modeling?
Definition
Optimality modeling: belief that a certin genotype that presumably produces an optimal phenotype will be selected.
-currency
-constraints
-decision variable
Term
what are the predictions of optimal foraginging theory explain each factor of optimality modeling?
Definition
foraging theory- organisms select foods the maximize the energy intake and therefore fitness. (currency=energy, constrain is time spent, decision is what to eat).
Term
what are the predictions of patch model expain each factor of optimality modeling?
Definition
it is a prey model that looks at what habitats (patches) roaming groups of predators choose to stop at.
Term
What is frequency dependent selection?
Definition
it s a process that can maintain polymorphism...the evolutionary strategy of one organism depends on the frequency of the other population (cant tell if it would be better to have more or less population from this info)
Term
What are the predictions of Hawk/Dove game theory?
Definition
a theory that explains how individuals should interact socially. The hawk always acts selfishly and will fight while doves share resources. In long term dove strategy saves energy but it not evolutionarily stable (pg 711).
Term
What is "ideal free distribution" of resource utilization?
Definition
A way to descrbe the filling of different habitat patches where each individual will exploit a patch of equal realized quality so resources arnt used up at best ones. (look at not only perceived density of resources but number of competitors)
Term
What is altruism? how did it come about?
Definition
behaviors that reduce the fitness of those performing them to help others. Came about with creatures that lived in social communities...like insects who can survive better in the group then out.
Term
List 4 benefits and 3 costs of living in a group
Definition
+ protection from preditors
+greater potential to find mates
+division of labor among specialists
+enhanced distribution for care of young
-increased competition for resources
-increased chance for spread of disease
-infanticide (loss of offspring)
Term
What is the coefficient of relatedness (r)? siblings? Cousins?
Definition
it is the probability that two individuals share genes.siblings .5, cousins .125
Term
What is hamilton's rule?
Definition
defines when creatures should be alturistic. this is when payoff in terms of common genes is enough to offset the cost of ones own genes. (c
Term
Name two characteristics of reciprocal altruism.
Definition
- if animals remain in contact ling enough for contact between individuals
-benefit is greater than cost
Term
List two behaviors of kin selection...describe one in detail
Definition
-alarm calling (this is where a sound is made to alert that a predator is nearby in squirrels...more likey for the one that made the sound to get attacked.
-extended families stay together
Term
What is extinction?
Definition
extinction is the end of a species or group of taxa.
Term
How do you calculate species Richness?
Definition
Shannon weimer index (-sumation pi ln pi)or simpsons index
Term
What are ecotones?
Definition
ecotones are the transition or boundary areas in a community.
Term
Name and describe the 2 models of community membership.
Definition
indiviualistic hypothesis- species in those habitat are there because of their tolerance to environment
interactive hypothesis- species are there because biotic interactions allow them to survive there
Term
What would the graph of an individualist hypothesis to population look like in comparison to interactive?
Definition
individualism would have random ups and downs where the populations of organisms would have same up/down motion on interactive
Term
What are factors effecting community composition?
Definition
enviromental conditions, biotic interactions, refugia, mass extinctions
Term
What are the 3 predictive models of species dominance in communities?
Definition
-geometric series-that when a species invades it gets a percent of the available resources and then the next gets the same percent of whats left...problem very few species get allocated anything enough to live off of
-random niche- no order allocation of resources is random
-lognormal distributions- that species have a set number of individuals (octaves), the number of species in each octave is plotted and this will give a normal distribution
Term
Which of the three predictive models of species dominance best fits to data from the field?
Definition
the log normal because it allows a large number of species to occupy an area
Term
What happens to the graph when r is changed?
Definition
small-expect sigmoidal plot
med-population is initially overshot
large-ossilations occur
Term
What is the difference in density-dependent and independent population regulation (ex)
Definition
dependent- number of individuals matters (ex:light for plants)
independent-wrong place wrong time factors (ex:hurricane)
Term
What is the difference between r (III) and K(I) selected species?
Definition
r reproduce quickly loose a lot of populations and are very dense in population
K are species that put a lot of time into reproduction and have higher survivorship and lower density
Term
what features would contribute to the fluctuation on population?
Definition
time delay in reproduction
recruitment-time to get to reproductive age
Term
What is the alternating genome hypothesis? How does it explain population cycles?
Definition
Term
What are metapopulations? What features of the environment lead to this pattern? What are 2 factors that determine the # of occupied patches?
Definition
collections of localized groups of same species (population of population). A eviroment could be island or an unfair resource distribution that causes patches of populations. Both size and density would influence the occupied patches.
Term
What is the rescue effect what type of population does it help?
Definition
It is caused by any immigration becauese metapopulation that are small would go extinct, but all they need is a little gene flow.
Term
Why are small populations more likely to go extinct? What affects extinction rate?
Definition
beause no way to addapt to changing conditions lack of heterozygosity.
-size of population
-immigration/emigraption mutation rates
Term
Diefine co-evolution
Definition
where the interaction between species creates an evolutionary response in both
Term
What is a niche?
Definition
the relational position of a species or population in its ecosystem to each other
Term
What is the competitive exclusion principal?
Definition
It states that two species cannot coexist on a single limiting resource.
Term
What is the difference between exploitive and interference competition?
Definition
exploitative- use of same limiting species at different time non competitive (morning vs night)
interference-competitive events occur simultaneously (water)
Term
What are the factors of phenotypic expression?
Definition
genotype and environmental variation
Term
How did brood parasitism evolve? What are the cost/benifits?
Definition
We see brood parasitism in
species and habitats where there are limited resources (in this case
either food or good nesting sites, mostly the latter). If an individual
is to successfully reproduce, it either needs to find a nest, OR put your
eggs in the nest of another. The benefits are you get to produce
offspring at a very low cost to you energetically. The costs are that you
stand to produce eggs, wasting courtship, etc. and have none survive. For
the female, this is either a win of 0.5 (in fitness value) per offspring,
or a complete loss.
Term
Other than environmental conditions what plays a role in community composition?
Definition
historical events, genetic drift, refugia, phylogenetic drift, mass extinctions
Term
How does the population graph change in N is greater?
Definition
K is reached faster
Term
From fluctuations on a population graph what can and can't we say about a species population?
Definition
Observations of fluctuating populations has given us some valuable lessons. We can track changes and look for periodicity, but the cause is
something that requires much more scrutiny. Seemingly simply
relationships among species have proven to not be simple, and even with all of the work we only have what appears to be part of the answer. Patchy distribution of resources and large r are two of the contributing factors. But sometimes predators, prey among other factors may be at work under certain circumstances.
Term
What is the altering genotype hypothesis? how might this explain population cycles?
Definition
he alternating genotype hypothesis is the suggestion that different factors are of different selective values at high vs. low densities. At
high densities, aggression and survival abilities are of value at high densities whereas maximum reproduction is best at low densities. However,
we do not have evidence to support this hypothesis.
Term
Can subdivided populations ever be beneficial to the inhabitance?
Definition
Yes, in competitive interactions where the superior competitor is not in all of the metapopulations, the inferior competitor may survive.
Term
How many licks does it take to get to the center of a tootsie pop?
Definition
3
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