populations

boom and bust

"Boom" characterized by rapid growth witch is followed by "busts" during which the population falls back to a minimal level.

density independent

Are not related to population size but are related to chance A volcano erupting A tsunami

What is BBECPO stand for?

B: biosphere (where ever life is on our planet) B: biome (larger areas with similar climate, deserts, rainforests etc) E: ecosystem (the elks, bison, temperature, amount of moisture etc) C: community (populations interacting...the elks and bison) P: population (all the elks in yellow stone) O: organism (one individual. One elk)

density dependent

Based on the size of the population Lack of food Space Disease

Not always K or r selected

Can be a continuum A sea turtle. Its big you might think its K selected but for birth, they lay a bunch of eggs in a whole and just swim away so more r selected also

Explain the difference between density-dependent and density-independent limiting factors. Discuss which of the two has the greatest immediate impact on a population.

Density dependent factors are ones that depend on the size of the population. These include lack of food, space, shelter, disease. Density independent factors are ones that do not depend on the size of the population. These include natural disasters. Density independent factors would have the greatest immediate impact on a population because the population doesn't need to be large for it to be affected. With density dependent factors, they affect a population when it is large and has almost or has reached its carrying capacity, which takes a while to reach. Density independent has the greatest immediate impact. With natural disasters all could die at once.

What is species composition?

Ex: count all of the different types of pine trees in a large area and how many there are of each and put them in a pie chart

population dispersion

Individuals of a population can be spaced in different ways, called dispersion patterns. In uniform dispersion, individuals are evenly spaced. In random dispersion, individuals are randomly arranged. The most common spatial arrangement is clumped dispersion, in which individuals are clustered together. clumped (school of fish, flocking birds, maybe clumped for protection.... uniform dispersion a repulsive force prevents them from being together ex: penguins because they have defined territories....random dispersion: dandilions seeds transported in the wind

What is symbiosis?

Interactions between the populations in an area...living together

Explain how the environment influences an organism's life history strategy.

Life History Strategy: traits that affect the life table of an organism. can be imagined as various investments in growth, reproduction, and survivorship. If an organism lives in a stable environment, then oftentimes, competition for resources can be intense, thus an organism will favor having just a few well prepared/ well raised offspring. If an organism lives in an unstable environment in which survival rate is low, they will reproduce a lot. They will have lots and lots of offspring in hopes that some will survive. You also don't know how long that environment will be the same as it is so you want to lay out as many eggs as possible before things start to change. So, might have a low reproductive age.

Where will our planet have the greatest species diversity?

Low species diversity at the equator because of stagnant weather Highest species diversity in rainforest Less species diversity at the poles

Males Vs. females r and K selection

Males are more r selected (lots of sperm) Females are more K selected (parental care)

exponential growth

N(t) = N(1+r)^t

What is total diversity?

Not only what is the largest amount that we have here, but what is the total amount that we have? Ex: all of the fungi collected in an area This shows us species diversity/ biodiversity

logistic growth

Population first grows exponentially, but then levels off because of limiting factors. The population eventually reaches a carrying capacity.

Age structure diagram/ population pyramid

Pyramid shape with mostly young people, will see exponential growth US doesn't look like this. The baby boomers are in the middle. It is flat at the bottom so will have logistic growth

Living commensalism?

Somewhere in between parasitically and mutualistically You are not harming them An example of inquilinism can be observed between barnacles and whales. Barnacles are normally sessile, or non-moving sea creatures. They rely on currents to bring food past them in order to eat. However, some barnacles have attached themselves to the sides of various sea life, such as whales, in order to have a more advantageous position in life. These barnacles benefit by receiving transportation all over the ocean, which exposes them to more currents and feeding opportunities than they would normally experience. The whale neither benefits nor is harmed by the barnacles.

What does K stand for

The carrying capacity. A max amount of organisms an area can support

carrying capacity

The max number an area can support

What does N stand for

The number of individuals in the population

per capita growth rate

The per capita birth rate minus the per capita death rate; the rate that determines how populations grow over any period.

Describe at least two conditions that might cause a population to undergo exponential growth.

The population might not be limited by food availability or shelter availability. Reintroduction to an area. When wolves were reintroduced to yellow stone park they underwent exponential growth (until they leveled off) An invasive species coming in to occupy a new niche. can exploit resources that havent been exploited before. limitless supply of food no predators unlimited space

k-selection

They are in it for the long haul. Exponential growth at first then logistic growth Humans, whales, some trees Characteristics: Stable environment Large body size Long life expectancy High parental investement Fewer offspring

Explain symbiosis in leaf cutter ants

They cut a leaf off and carry it back with them into their mound. They feed it to a fungus, which is within that leaf cutter ant colony. They chew up the leaf and feed it to the fungus. The fungus breaks down the leaf's cellulose and produces a sugar that the ants can then eat. The fungus gets a constant supply of food and a place to live and the fungus provides food for the ants. The fungi are never infected. There is bacteria living on the ants. Those are similar to some of the bacteria we use to make penicillin and our antibiotics. Thus, the bacteria and ant have a mutualistic relationship.

r-selection

Those that base their life on r (growth rate) Want to quickly grow and exploit a niche as fast as they can Characteristics of r selected species: Normally live in an unstable environment High fecundity (can make lots of babies and fast...little parental care) Small body size Early maturity Short generation time Dispersed

What if we get a negative growth rate?

We approach a limit, zero

Explain how limiting factors in a population lead to natural selection.

When there are limiting factors in a population, this means that a population can only grow to be so big. It has a carrying capacity. Once it reaches this capacity, natural selection will occur. At its carrying capacity, pressure on the organisms will be greater and competition for resources will increase. Organisms in a population that are most fit for the environment will survive and reproduce and pass their genes to their offspring whereas organisms in the population that are less fit, will die off because of increased competition for resources (caused by limiting factors).

Living mutualistically?

You both help One example of a mutualistic relationship is that of the oxpecker (a kind of bird) and the rhinoceros or zebra. Oxpeckers land on rhinos or zebras and eat ticks and other parasites that live on their skin. The oxpeckers get food and the beasts get pest control.

Living parasitically?

Your damaging one Tapeworms are segmented flatworms that attach themselves to the insides of the intestines of animals such as cows, pigs, and humans. They get food by eating the host's partly digested food, depriving the host of nutrients. Fleas harm their hosts, such as dogs, by biting their skin, sucking their blood, and causing them to itch. The fleas, in turn, get food and a warm home.

negative feedback

a regulatory mechanism in which the stimulus causes the opposite output in order to maintain the ideal level ex: The hypothalamus of a human responds to temperature fluctuations and responds accordingly. If the temperature drops, the body shivers to bring up the temperature and if it is too warm, the body will sweat to cool down due to evaporation.

Describe the limiting factors that prevent many populations from reaching their carrying capacities.

disease, limited food/water, natural disasters, predators, limited shelter, different weather patterns etc. The carrying capacity is determined by the resources and stuff that is actually in the environment (density dependent) and the independent limiting factors (natural disasters, etc, by chance stuff) prevent them from reaching carrying capacity.

population density

is a measurement of population per unit area or unit volume;

Explain the difference between k-selected and r-selected species and, using what you know about them, describe how they are adapted to the environments in which they live.

k-selected: live in more stable environments that have food, maybe less predators, etc. so they have adapted to that by investing more energy into their offspring and creating these stronger more suitable offspring. r-selected: unstable environment. things are changing maybe a lot of predators. so they reproduce a lot. Their is a strong chance that you will be eaten so you want to reproduce as fast as possible. k: carrying capacity (more into carrying capacity) r: reproductive growth rate (quick reproductive rate) r doesn't stay the same forever. Moves into logistic growth because limited by factors

demographics

studying the human population

doubling time

the period of time required for a quantity to double in size or value.

life history

the sequence of events related to survival and reproduction that occur from birth through death.

survivorship curve

type I:Is what humans are Most survive and make it through teen years and middle ages etc and die when old. Because we give lots of parental care to our offspring type II: Robins are an example Die at a linear rate type III: Frog population Give birth to lots of eggs but not a lot survive when young a few survive