Ecology

__ Organisms and Population/ Ecology __ __Labs:__ The Salamander Lab- The purpose of this lab was to see how environmental changes and natural selection calls for certain mutations and adaptations. The summary of data is that for each round, mutations happened to our salamanders and an environmental change would happen and depending on that mutation it was either beneficial or harmful to the salamander. Towards the last round, if there was more than one salamander in a box, then they all died. This is because there wasn’t enough food and resources for the salamanders to have, which is called competitive exclusion. This was a valid experiment because it showed us that mutations facilitate the changes in species and that through environmental change, natural selection will choose the mutations that survive and which ones will die off.


 * __Summary:__**
 * Ecology** is the distribution of organisms. In other words, why species are found where they are.
 * Ecology** is the scientific study of interactions of organisms with one another and with the physical and chemical environment.
 * __ BIOMES __**
 * **Distribution of Organisms:** ** Why are species found where they are? **
 * **--**** Biotic Factors-living components of ecosystem **
 * ** Ex: Adaptations, Interactions with other species, Behavior and Habitat Selection, **
 * ** --A biotic Factors-non living components of ecosystems **
 * ** Ex: Temperature, Water, Sunlight, Wind, Rocks and Soil, Disturbances **
 * **Ethology** ** is the study of behavior in natural habitat, thought that behavior was based on instinct not thought. **
 * **Comparative Psychology**** is the study of mental process underlying behavior **
 * ** Ex: learning, imprinting, associative learning, maturation **
 * **Behavioral Ecology**** is the study of how behavior increases evolutionary fitness **
 * ** Ex: Foraging Behavior, Social Behavior **
 * __ POPULATION ECOLOGY __**
 * ** Overview **
 * ** Organisms, Populations, Communities, Ecosystems, Biosphere **
 * ** Sampling Populations-mark and recapture **
 * ** Population growth **
 * **K**=caring capacity-the maximum population an environment can support indefinitely.
 * 1) if K>N(number of organisms in the population) then the population growth rate is positive
 * 2) if K<N then the population growth rate is negative (population is OVER caring capacity)
 * 3)if K=N then population levels off and growth stops
 * Logistic growth à S-curve
 * Factors that affect population growth-density independent and dependent factors, age structure (more young=greater growth), clutch size (more offspring= more growth), survivorship (high survivorship=greater growth)
 * **Life History Strategies-** traits that affect reproduction and survival
 * 1) r-strategist=many offspring produced but small chance of survival
 * 2) k-strategist=fewer offspring produced but each one has a high chance of survival

**__COMMUNITY ECOLOGY __** · Interaction between species- Competition (-,-) Predation (+,-) Mutualism (+,+) Commensalism (+,0) Parasitism (+,-) · Diversity is stability · Factors affecting diversity- environmental patchiness, keyston predators, competition · Succesion is the transision in the dominant species through time- (primary succession and secondary succesion)


 * __ECOSYSTEMS-__**
 * Flow of energy (enters from the sun and exits as heat)- Trophic levels (producers and consumers) and the food web
 * Energy Transfers- Primary productivity and factors limiting productivity
 * Secondary productivity
 * Cycling of materials: Water cycle, Carbon cycle, Nitrogen cycle and processes like nitrogen fixation

**__HUMAN IMPACTS ON THE BIOSPHERE__ ** · Agriculutre (Industrialized agriculture and slash-and-burn agriculutre) · Global Warming(Greenhouse gases, Greenhouse effect) o The effects are melting of polar ice caps, change in precipitation patterns, and altered distributions and behaviors of species o Solutions are minimizing the burinin of fossil fuels · Depletion of the Ozone Layer (CFCs) o Impacts are incresed incidence of skin cancer and cataracts, and harm to crops and other primary producers o Solutions are CFCs are now banned · Acid Rain (SOx and NOx) o <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Impacts are lowers pH of soils and freshwater · <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Loss of Biodiversity

__Vocabulary words and definitions__ Ethology: study of behavior in natural habitat; believed that behavior was based on instinct, not thought Comparative psychology: study of mental processes underlying behavior; emphasized controlled, lab experiments Habituation- Loss of responsiveness to stimuli that lack information Imprinting- Learning limited to specific time of life called the critical period Associative learning- associating one stimulus with another Classical Conditioning- associate an arbitrary stimulus with reward or punishment (Ivan Pavlov) Operant conditioning: associating a behavior with a reward or punishment (B.F. Skinner) Maturation- Change in behavior resulting from changes in development. Behavioral Ecology: study of how behavior increases evolutionary fitness Optimal Foraging Theory: animal foraging strategies optimize benefits (energy gained) and minimize cost (energy used to find food) Agnostic behavior: competition between two members of same species (fighting for food, mates...) Dominance Hierarchies- Randing of status; maintains order within a group to minimize fighting Territoriality- an individual (or group) has its own territory, which it defends ("Get off my turf holmes!") Pheromones: chemical signals smelled by others (common in insects and mammals) Monogamy: One male and one female Polygamy: Many females and one male Altruism- sacrificing yourself for the good of anothre Reciprocity- help another individual in order to receive help later Populations- individuals of the same species in a particular location Communities- individuals of different spevies in a partivular location Ecosystems- all living and non-living factors in a particular location Biosphere- portin of earth inhabited by life Group Selection- groups that help each other do better than the group that do not Kin Selection- helps relatives because they share genes Population Density- number of individuals per unit area Population Distribution- clumped, uniform, or random R-strategists- have many offspring but each has a small probability of surviving K-strategists-produce fewer offspring, but each has a high probability of surviving Competition- when two species rely on similar resources Niche-ecological role of a species-resources it uses how it fits into the food web Resource partitioning- two species utilize different parts of their niche to avoid competition Predation-when one benefits from the others losses Mimicry- One prey species resembles another Batesian Mimicry- harmless species resembles a poisonous species Mullerian Mimicry- two harful species resemble each other (bees, wasps) Symbiosis-close association between two species Mutualism-two species benefit each other Commensalism- one species helps another but it is neither helped nor harmed in the relationship Parasitism- parasite gets nutrients from the host Primary Succession-begins with no living organisms (volcanic island) Secondary Succession-begins with a disturbed community (fire) Climax community-stable persists for a long time usually dominated by K strategists Facilitative Interactions- one community paves the way for the next Inhibitory Interactions- one community prevents the establishment of another Trophic Levels - feeding the relationships within an ecosystem Primary Producers - autotrophs; capture light energy of the sun and convert it into usable chemical energy (i.e. photosynthesis) Primary consumers - heterotrophs; herbivores Secondary consumers - heterotrophs; carnivores that eat herbivores Tertiary Consumers - heterotrophs; carnivores that eat other carnivores Decomposers - heterotrophs; Feed on dead organisms; recycle nutrients Food web - illustrates movement of energy, most of energy is eventually lost as heat Primary productivity - amount of light energy converted to chemical energy (organic compounds) via photoynthesis Secondary productivity - amount of chemical energy in consumer's food that is converted to their own new biomass. Trophic efficiency- % of energy used to produce a new biomass Production efficiency- % of energy used to produce new biomass Biomagnification- Toxins get more concentrated as you move up the trophic levels. Water Cyle- Evaporation->Condensation->Precipitation->Runoff-> Percolation Carbon Cyle- Photosythesis and Cellular Respiration; Light Energy+6Co2+6H20-> C6H1206+ 6O2; C6H12O6 +6O2-> 6CO2 +6H2O+36ATP Eutophication- addition of nutrients to water, resulting in raid algal growth Fragmentation- breaks habitat into patches (e.g. building a ski slope in a forest.) Overexploitation- Harvesting plants or animals faster than the population can replenish itself (ex. Ivory hunting on elephants, commercial fisheries, etc.)

__People and their experiments__ B.F. Skinner - Skinner box. He put a rat in a box containing a lever that, when pushed, released food. The rat quickly learned to push it for food because he associated it with a reward. The strongest results typically occur when the reward is inconsistent.

Ivan Pavlov's experiment- Classical conditioning (associate an arbitrary stimulus with reward or punishment) - simultaneously sprayed powdered meat into dogs mouth (this produced salivation), then he rang a bell, eventually dogs became conditioned to salivate when they heard the bell alone

Karl von Frisch- Bee waggle dance His work centered on investigations of the sensory perceptions of the honey bee and he was one of the first to translate the meaning of the waggle dance. His theory was disputed by other scientists and greeted with skepticism at the time. Only recently was it definitively proved to be an accurate theoretical analysis. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%; margin: 0in 0in 0pt 0.75in; text-indent: -0.25in;">1) On a wall of the hive, they do a figure 8 while waggling <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%; margin: 0in 0in 0pt 1.25in; text-indent: -0.25in;">a. Distance; proportional to number of waggles <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%; margin: 0in 0in 0pt 1.25in; text-indent: -0.25in;">b. Direction: angle relative to vertical surface of hive= angle relative to sun <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%; margin: 0in 0in 10pt 0.75in; text-indent: -0.25in;">2) Regurgitate food so other bees know type available