Ecology Test 1

This is both overhe-top and probably too brief. Do with it what you will; hope it helps!

Define Ecology

systematic study of the interactions between the biotic and abiotic parts of an ecosystem

• Not ES (rather, it is a subset of ES)

• NOT environmentalism

• NOT zoology

What do Organisms Want?

• one goal: pass on their genes

• how pass on genes?: interact with the environment

Define Ecosystem

the substrate/medium where ecological interactions occur

• e.g.: in the desert, abiotic factors of the ecosystem are= heat, sun, cold nights, sporadic rain; biotic factors=predators, competitors, vegetation

Levels of Ecology

• physiological ecology

• population ecology

• community ecology

• landscape ecology

Physiological Ecology

“How does morphology/physiology effect how an organism interact w an ecosystem?”

Population Ecology

ecology of populations (waow, shocker)

Define Population

group of freely interbreeding individuals of same species that occupy a given area

Define Community

multiple populations in a given area

• usually defined taxonomically

Define Species

organisms that can reproduce and make viable offspring

• technically we can’t define ‘species,’ it’s complicated just trust me you’ll learn in animal div if you take that

Community Ecology

studies presence/absence of a species in a community (and why), relative abundances, interspecific interactions, etc

Define Landscape

area of land and water that includes a no. of communities and habitats

How do we study Ecology?

• scientific method: observation, hypothesis, test it, etc…

• experimetal studies

• observational studies

• models (Dr. Box…): ecology is a model-heavy field

Experimental Studies

controlled environment for data collection

Observational Studies

viewing you environment

Consensus

When we fail to disprove something we make a “consensus” that that said something is proven to occur.

MODELS in Ecology (no Jesse, not fashion models)

• Mathematical models (e.g. y=mx+b)

• Verbal models (e.g. Darwin’s Theory of Evolution)

• Graphical models

• some models are quantitative, some are qualitative

What determines climate?

1. sun: only 51% of rays hit earth’s surface

   • earth retains heat via greenhouse effect

   • PAR: photosynthetically active radiation

2. atmospheric pressure: 1 ATM at sea level

   • high elevations have RARIFIED AIR

3. global air and oceanic currents

4. air moisture: evaporation is endothermic cooling, and condensation is exothermic heating.

   • SVP: water vapor in air precipitated @ saturated vapor pressure

5. rain shadows: the side of a mtn that gets less rain than the other is in a “rain shadow”

is climate homogenous?

nope (we got microclimates baby)

What is a mechanism of evolution?

natural selection: “fittest survive and reproduce”

How does Natural Selection occur?

variation

• sometimes is heritable

• allows for some organisms to be more fit to survive

• good traits are passed on, and overtime there are changes in the distribution of traits (variation), then evolution occurs.

Gene Flow

movement of genes between populations (aka two islands, each with one population of a bird species. The birds fly to the other island to mate with the population on the other island; this causes gene flow to occur between the two islands)

Genetic Drift

random changes in gene frequency (aka the kinked tails in florida panthers due to inbreeding)

Adaptation

a beneficial heritable trait developed overtime by natural selection

• passed on via DNA

Where in our genetic makeup does variation occur?

Alleles

Genotype

Genetic makeup; our combinations of alleles in our genome that code for our traits

Phenotype

the physical expression of our genetic traits

Phenotypic Plasticity

the ability of a genotype to produce more than one phenotype under different environmental stresses

• e.g. cavefish develop scale pigment when under a light

How do species evolve?

1. natural selection

2. genetic drift

3. gene flow

Hardy-Weinberg Principle (Mating)

if mating is random, no natural selection, and therefore no evolution, occurs.

Assortative Mating

non-random mating

• Positive Assortative Mating: mate seeks phenotypically similar mate

• Negative Assortative Mating: mate seeks phenotypically dissimilar mate

Clines

gradual but quantifiable phenotypic change over a species range

• e.g. whitetail deer are different sizes across their massive range

Ecotypes

a big change in phenotype over a small range based on an abrupt change in habitat

• e.g. tiger salamanders (aquatic versus land ecotypes)

Trade-Offs

some adaptations have an equal amount of beneficial qualities and negative aspects

• e.g. an animal may be large (good for minimizing amount of viable predators, but bad for being energy efficient)

Adaptive Radiation

when trade offs in one species vary over a large range

• e.g. bear species have a large range of habitat-specific adaptations

Autotrophs

organisms that make their own food

• phototrophs: use sun’s energy to make le foods

• chemoautotrophs: make organic molecules from chemicals

Photosynthesis

needs: light, CO2, Water. Makes sugar, O2.

evaportranspiration

evaporation on leaves create a concentration gradient that pulls water from the roots up

Plant types (Based on how much water they need)

Xerophytes - minimal water

Mesophytes - medium amt of water

Hydrophytes - live in watery habitats

Factors Affecting Photosynthetic needs

• light

• water

• heat

• nutrients

Nutrients a Plant Needs

Macros: C HOPKiNS CaFe Mg

• carbon, hydrogen, ocygen, phosphorous, potassium, nitrogen, sulfur, calcium, iron, magnesium

Wetland water is usually…

• hypoxic: low in O2

• anoxic: no O2

Adaptations of Aquatic Plants

• Aerenchyma- interconnected chambers in plant tissue in the stem

• Adventitious Roots - roots coming off the stem of the plant rather then the base (above the H2O line)

• Pneumatophores - “fingers” that grow off the roots up above the H2O line

Halophytes

Plants adapted to salt water

What is the Human Niche?

Niche switching

• Our niche is the ability to fit into any niche. It is a paradox. We are generalist species that contains specialists.

Culture versus Consciousness

• consciousness is good for problem solving

• culture provides habits for best execution of ‘living’

  • so, when culture doesn’t help us anymore, we use consciousness to change it

Sucker’s Folly

tendency of concentrated short-term benefit not only to obscure risk and long-term cost, but also to drive acceptance even when the net analysis is negative.

• e.g. the Titanic

Epigenetic

“above the genome”

Omega Principle

1. epigenetic regulators (culture) are superior to genes in their influence on us, in that they can adapt more rapidly than genetic adapations

2. epigenetic regulators (culture) evolve to serve the genome

Are we fish?

yes.

Precautionary Principle

just because you can, doesn’t mean you should

Chesterton’s Fence

urges caution in making changes to systems that are not fully understood.

• two folks find a fence while they walk down a road. One wants to take it away. The other one says, “hey let’s find out why it’s here first.”

Reductionism

Reducing complex systems to a few easily observable, easily measurable parts at the expense of nuance.