EC 253 Midterm

Levels of Ecology, Natural Selection and Evolution, Community Ecology, Ecosystem Ecology

Scientific Method

We observe, question, hypothesize, replicate, report findings, experiment/observe

Individual

single individual organism of a species

Population

a group of individuals from the same species

Community

a group of multiple species living in the same habitat

Ecosystem

Assemblages of organisms together with their physical enviornment

Biosphere

the environments and all life on earth

Geosphere is

Solid earth

Hydrosphere is

Water

Atmosphere is

Air

Mutualism

(++), both species benefit from the interaction

Commensalism

(+0), one species benefits, while the other is unaffected

Predation

(+-), One species kills and eats the other

Parasitism

(+-), One species feeds off the other

Competition

(- -), Two species fight for resources

Interference Competition

one organism excludes another organism’s access to resources

Exploitation Competition

one organism uses up all the resources, reducing levels for others

Amensalism

(-0), one species is harmed/destroyed, while the other is completely unaffected

Neutralism

(00), A theoretical or rare interaction in which two species dont impact each other

Ecological systems

Complex networks on earth are regulated by feedback

Negative feedback

an affect that opposes change, regulates

Positive feedback

an effect that increases change, exacerbates the previous state

Grey Wolf Reading:

After the founding of the park in 1872, native Grey Wolf populations began drastically decreasing due to poaching and extermination. By 1973, they were listed under the Endangered Species Act. By 1994, Wolves were reintroduced back into Yellowstone Park, solidifying their populations.

• Impact: Wolves hunt Elk, keeping abundances under control. New growth in Willows and other native plants due to lack of overgrazing. In-turn recovered beaver colonies. Smaller predators declined; small prey recovered

Biosphere 2 Reading: how did the experiment go?

unsuccessful

Biosphere 2 Reading: What went wrong?

• Outside intervention, cockroach infestation, needed oxygen to be brought in, Oxygen levels plummeted, making the inhabitants sick, while carbon dioxide (CO2) levels increased. Countless animals died, including the pollinators the plants needed to reproduce. And although the "biospherians" did survive on their homegrown food, they lost weight to the point where they became a case study for calorie restriction  

Biosphere reading 2 : What went right?

• Many new findings about the environment, the importance of wind for tree’s strength , they learned that rich soil/microbiomes can reduce oxygen levels  

Biosphere reading 2: What was the media response like?

negative

Thomas Malthus population theory

when population growth goes unchecked, it can exceed the growth of the means of subsistence 

• Actual population growth is typically regulated by food supply, disease, etc

Carrying capacity

the capacity for an environment to sustain a population 

• Once exceeded, populations typically level out or decline

Logistic growth

 s curve thats regulated by carrying capacity 

Expotential- no end in sight

Natural Selection

When organisms with traits best suited to their environment survive and reproduce, passing on those traits to the next generation.

Differences in survival and reproduction due to natural processes 

“Fitness”

• the relative ability to leave successful offspring 

Bottleneck/drift

When traits are maintained or developed that are used as signals to the opposite sex

Artificial selection

when humans selectively breed individuals who have desirable traits including animals and plants/crops

Evolution

changes to genetic makeup of a population over time

Natural Selection

Happens to an individual

Reading on Mojave Desert

Dependent on each other, co evolution and one cannot exist without the other, mutualism REREAD

Genotype

the complete and unique genetic makeup of an individual 

Phenotype

the set of observable characteristics or traits of an organism like eye color, hair color, height, etc 

Genes

the basic unit of our DNA

Alleles

the alternate versions of a specific gene found on our chromosomes

Heterozygous

means one dominant and one recessive (one upper-case, one lower)

Homozygous

means two dominant or two recessive

Polygenic traits

a phenotype that's determined by multiple genes working together

Mutations

mistakes when DNA replicates 

Community

all the species living in one habitat 

Producers

1st trophic level: plants

Primary consumers

2nd trophic level: Herbivores

Secondary consumers

3rd tropic level: Consumers that eat the primary consumers

Tertiary consumers

4th tropic level: Consumers that eat consumers below it

Quaternary consumers

5th trophic level: Apex predators

Species richness

the number of different species

Species evenness

the relative abundance of each species

Species diversity

a combination of richness and evenness

Dominant species

the most abundant

Keystone species

species who presence or absence critically affects the function of their enviornment

CO2 stands for

Inorganic Carbon

OC stands for

organic carbon

Sunlight + H2O + CO2 > O2 + Glucose is

Photosynthesis

CO2 is:

Metabolized OC, When a consumer eats the plant

When a consumer performs respiration, they’re releasing:

CO2

When animals die and decay, they release:

OC

As dead matter is decomposed by microbes:

OC is converted to CO2

As fossil fuels are burned:

OC becomes CO2

Nitrogen Fixation

N2 (N Gas) is converted to usable nitrogen NH3

Nitrification

The conversion of NH3 (ammonia) to NO2 (Nitrite) to NO3 (Nitrate)

Denitrification

NO3 turns back into N2

Ammonifcation

Decomposers release NH4+(ammonium) back into the environment, where it can then be converted by notifying bacteria

Weather

is short term

Climate

is the long-term average weather in an area

Forests

defined by their dense canopies 

types: Temperate, tropical, boreal

Grasslands

mostly made up of a variety of different grass species

Deserts

are dry/minimal rainfall, often lacking vegetation

Tundras

cold conditions all year round, with heavy snowfall

Aquatic

organisms live and interact in a water based environment

Transitional Ecosystems

typically environments where two different ecosystems meet and integrate