EcoEvo Final Exam

Define behavior

The way organisms respond to each other and to particular cues in the environment.

Define ethology

The study of animal behavior.

Define trade-off

Compromises between two desirable but incompatible activities.

Define relative benefit

Differences between the costs and benefits of optimality models.

Define kin selection

Selection of traits that increase the survival and ultimately the reproductive success of one’s relatives rather than oneself.

What are the 4 types of social behaviors? Can you define each?

1. Fixed action pattern: behaviors performed by all members of one sex of one species in a stereotypical pattern. (e.g. male sticklebacks display aggressive fighting toward other males to protect their territory).

2. Imprinting: an irreversible one-time learning process that occurs in an early development phase. (e.g. ducklings and goslings follow the first moving object they encounter for safety, typically their mother).

3. Eusociality: a type of animal society where individuals live in large groups with overlapping generations, cooperation in nest building, brood care, and reproductive dominance by one or a few individuals. (e.g. ants, bees, wasps, termites, and mole rats).

4. Dominance hierarchy: a social ranking among individuals in a group determined through fighting or other contests of strength or skill. (e.g. alpha wolves leading their pack).

What are the 3 benefits of group living?

1. Reduced predation chances

2. Increases success

3. Easier to locate a mate

What are the 4 costs to group living?

1. Easier to be found by predators

2. Higher parentage loss

3. Higher chance of disease/parasites spreading

4. Higher intraspecific resource competition

What is the optimal group size?

The size that results in the largest relative benefit.

What are Tinbergen’s four behavioral ecology questions? Which are proximate and which are ultimate questions? What are the four key terms that represent these 4 questions?

1. How is a behavior produced? Control: response to changes in environment

2. How does a behavior develop? Development: the behavior is an instinct or has been learned from others

3. What is the adaptive value of the behavior? Consequence: Better resources

4. What is the evolutionary history of the behavior? Phylogeny: Birds evolved from ancestors that migrated

What are optimality models? Can you identify the ones we discussed? What is the overall goal in terms of optimality models?

• Optimal group size

• Optimal territory size

• Optimal foraging strategy

• Optimal migration

Define community

A group of populations occupying a particular space or habitat.

Define ecotone

A boundary created by changes in environmental conditions over a short distance, accompanied by a major change in species composition.

Define keystone species

A species that substantially affects the structure of communities despite the fact that individuals of the species might not be abundant.

Define apex predator

An animal at the top of the food chain who has no predators of its own.

Define ecosystem engineer

An organism with a greater role in ecosystem and their presence exerts control on ecosystem structure and function.

Define introduced species

a species introduced to a region of the world where it has not historically existed (also known as exotic species or non-native species).

Define invasive species

an introduced species that spreads rapidly and has a negative effect on other species or human economies.

Define food chain

linear representation of how different species in a community feed on each other,

Define food web

a complex and realistic representation of how species feed on each other in a community.

Define trophic levels

levels of a food chain or food web.

Define guild

a group of species that feed on similar items within a trophic level.

Define trophic cascade

indirect effects in a community that are initiated by the removal or addition of a predator.

Define community stability

the ability of a community to maintain a particular structure.

Define community resilience

time it takes after a disturbance for a community to return to its original state.

Define community resistance

how much a community changes when acted upon by some disturbance.

Define alternative stable state

when a community is disturbed so much that the species composition and relative abundance of populations in the community change, and the new community structure is resistant to further change.

What drives community zonation?

Different tolerances of species to various environmental abiotic and biotic factors.

What is the difference between independent and interdependent communities?

• Independent is when species do not depend on each other to exist

• Interdependent is when when species DO depend on each other to exist

What is species richness? What is the problem with this measure?

• the number of species in a community

• rare and common species are treated equally, does not factor in relative abundance

What is relative abundance? What is species evenness?

• relative abundance: the proportion of individuals in a community represented by each species

• species evenness: a comparison of the relative abundance of each species in a community.

What are the Simpson’s Index and Shannon-Wiener diversity indices?

• Simpson’s index: a measurement of species diversity, sensitive to dominant species

• Shannon-Wiener index: a measurement of species diversity, sensitive to rare species

What is the relationship between species richness and productivity? ...and habitat diversity? ... community resistance? ...community resilience?

• Productivity = relationship varies a lot

• High Habitat diversity = high species richness

• High community resistance = high species richness

• High community resilience = high species richness

What is the intermediate disturbance hypothesis?

This hypothesis tells us that more species are present in a community that occasionally experiences disturbances than in a community that experiences frequent or rare disturbances.

What is the difference between primary producers, primary consumers, secondary consumers, tertiary consumers, and quaternary consumers? What does it mean that some of these trophic connections cause direct effects and some cause indirect effects.

• Direct effect: an interaction between 2 species that does not involve other species.

• Indirect effect: an interaction between 2 species that involves one or more intermediate species.

What is the difference between communities that are controlled by top-down vs bottom-
up forces?

• top-down: abundance of trophic groups is determined by the existence of predators at the top of the food web

• bottom-up: abundance of trophic groups is determined by the amount of energy available from the producers in a community.

Define succession

The process of directional change by which the species composition of a community changes over time.

Define seral stage

Each stage of community change during the process of succession.

Define chronosequence

Sequence of serial stages

Define pioneer species

the earliest species to arrive at the site

Define climax community

the final seral stage in the process of succession.

Define fire maintained climax community

a successional stage that persists as the final seral stage due to periodic fires.

Define grazer maintained climax community

when a successional stage persists as the final seral stage due to intense grazing.

Define transient climax community

a climax community that is not persistent.

What are some characteristic traits of early vs late successional species?

Early successional species

• Number of seeds: many

• Seed size: small

• Growth rate: fast

What is the difference between primary and secondary succession? Can you define and give examples of each?

• Primary succession: succession occurring on a landscape that has no biological legacy (e.g. development of communities in habitats devoid of plants or soil such as sand dunes, lava flows, and bare rock).

• Secondary succession: succession occurring on a landscape that has a biological legacy (e.g. in habitats that have no plants but still has soil like after a forest fire).

How are species richness and succession related?

Species richness will increase as succession proceeds but will eventually level off or decrease slightly at climax community.

What are the four succession mechanisms that have evolved from the classical succession models? Can you define all four?

1. Facilitation: the presence of one species increases the probability that a second species can become established.

2. Inhibition: one species decreases the probability that a second species will become established.

3. Tolerance: the probability that a species can become established depends on its dispersal ability and its ability to persist under the physical conditions of the environment.

4. Null: a mechanism of succession which involves only the chance survival of different species and random colonization of new species.

Define ecosystem

One or more communities of living organisms interacting with their nonliving physical and chemical environments.

Define primary productivity

The rate at which solar or chemical energy is captured and converted into chemical bonds by photosynthesis or chemosynthesis.

Define net secondary productivity

The rate of consumer biomass accumulation in a given area.

Define ecological stoichiometry

The study of the balance of nutrients in ecological interactions, such as between an herbivore and a plant.

What is the difference between primary and secondary productivity?

• Primary: rate that autotrophs convert energy into organic compounds.

• Secondary: rate that heterotrophs generate new biomass.

What is the difference between autotrophs and heterotrophs? Can you define both? Can you name the types of both autotrophs and heterotrophs

Autotroph: acquires energy from non-living sources

• Photoautotroph: uses light energy

• Chemoautotroph: uses chemical energy

Heterotroph: acquires energy by consuming living sources

• Herbivore: eats plant material

• Carnivore: eats animal material

• Saprotroph: eats dead/decaying material

What are the various calculations of primary productivity? How does respiration factor into productivity?

NPP = GPP - Respiration

where NPP = net primary productivity and GPP = gross primary productivity

Respiration is the energy cost for metabolic needs.

What are the major factors that can limit primary production in both terrestrial and aquatic systems?

• Light capture

• Temperature & Precipitation

• Nutrients

What are tools used in measuring productivity?

• Weighing harvest

• Satellites & drones

• Gas exchange instruments

• Light/dark bottle techniques

What are ecosystems with the highest and lowest global primary productivity?

For terrestrial environments….

• Highest = tropical rainforest

• Lowest = extreme desert

For aquatic environments….

• Highest = swamps & marshes

• Lowest = open ocean

Who is the founder of Pyramid of Numbers? In the Pyramid of Numbers, what is the relationship with organism size as trophic levels increase? What is the relationship with organism abundance as trophic levels increase? What is the relationships with energy as trophic levels increase? How much of the energy that is consumed at one trophic level is available to the next trophic level? What is the name of the rule/law that is associated with this? Do all systems follow the same pattern with energy and biomass?

• Charles Elton

• Organism size increases as trophic levels increase

• Organism abundance decrease as trophic levels increase

• Energy decreases as trophic levels increase

• 10%

• Lindeman’s rule of 10

• No

What are the differences between egested, assimilated, and respired energy? Measuring secondary productivity can be viewed as a balance between these energetic transfer. Can
you define: Consumption Efficiency, Assimilation Efficiency, Net Production Efficiency,
and Ecological Efficiency?

• Egested energy: the portion of consumed energy that is excreted or regurgitated.

• Assimilated energy: the portion of energy that a consumer digests and absorbs

• Respired energy: the portion of assimilated energy a consumer uses for respiration

• Consumption efficiency: percentage of energy or biomass in a trophic level that is consumed by the next higher trophic level

• Assimilation efficiency: percentage of consumed energy that is assimilated

• Net production efficiency: percentage of assimilated energy that is used for growth and reproduction.

• Ecological efficiency: percentage of net production from one trophic level, compared to the next lower trophic level.

Define watershed

An area of land that drains into a single stream or river.

Define decomposition

A process where dead organic material is broken down into simpler compounds by bacteria & fungi.

What are the major global elemental cycles discussed in class?

• Hydrologic cycle

• Carbon cycle

• Nitrogen cycle

• Phosphorus cycle

What are the steps of the hydrologic cycle? How are humans influencing it?

1. Water is evaporated from aquatic & terrestrial habitats and combines with water from plant evapotranspiration forming clouds.

2. Water returns to earth as precipitation

3. Precipitation either infiltrates the soil or runs off to nearby bodies of water

• Construction sites, causing erosion by removing plants, pumping groundwater for various uses, and activities that contribute to global warming.

What are the steps of the carbon cycle? How are humans influencing it?

1. Producers take up carbon from the atmosphere and water

2. This carbon is transferred to consumers, scavengers, and decomposers

3. This carbon is returned to the atmosphere through respiration

4. Carbon is exchanged between atmosphere & ocean as well as ocean & sediment

5. Carbon stored underground turns into fossil fuels which can be extracted

6. Carbon is returned to the atmosphere through burning or fossil fuels, terrestrial ecosystems, and volcanic activity.

• We have increased levels due to burning fossil fuels & deforestation

What are the steps of the nitrogen cycle? How are humans influencing it?

1. Starts with nitrogen gas in the atmosphere

2. nitrogen fixation converts it into a form producers can use

3. fixed nitrogen can be assimilated into producers & consumers, ultimately decomposes into ammonium by mineralization

4. Ammonium is converted into nitrite and then nitrate

5. Nitrate can be converted into nitrogen gas through denitrification

• We have increased levels due to burning fossil fuels, production of nitrogen fertilizers, and planting nitrogen fixing crops.

What are the steps of the phosphorus cycle? How are humans influencing it?

1. Phosphate rocks weather over time releasing phosphorus

2. Phosphorus is taken up by producers and moves through the food chain until released through waste or decomposition

3. Excess phosphorus runs off or leaches out of the soil into aquatic habitats

4. In the ocean phosphorus combines with calcium or iron to reform phosphate rocks.

• We have increased levels due to production of detergents containing phosphate.

Why is decomposition important in the elemental cycling in ecosystems? How does decomposition vary between terrestrial and aquatic systems?

• It is important because it returns vital nutrients back into the environment allowing continuous reuse by producers and preventing accumulation waste.

Terrestrial

• Slower rate due to varying environmental conditions

• Primarily driven by fungi

Aquatic

• Faster rate due to constant moisture

• Decomposition occurs in the water column before settling in sediments, water allows for faster nutrient recycling as well

What is eutrophication? How is this related to elemental cycles in ecosystem? What are dead zones and how are they related to eutrophication?

• An increase in the productivity of aquatic ecosystems

• Dead zones are areas in oceans or lakes where oxygen levels are so low that most aquatic life can’t survive there. They are a direct result of eutrophication.

Define climate

The typical atmospheric conditions that occur throughout the year, measured over many years

Define weather

The variation in temperature and precipitation over periods of hours or days.

Define soil

The layer of chemically and biologically altered material that overlies bedrock or other unaltered material at Earth’s surface.

How do we get climate?

• The greenhouse effect

• Unequal heat going of Earth by the Sun

• Air currents

• Ocean currents

• smaller-scale geographic features

What is the Greenhouse Effect? How does this lead to global warming?

• The process of solar radiation striking Earth, being converted to infrared radiation and being absorbed and re-emitted by atmospheric gases.

1. Some of the solar radiation penetrates the atmosphere where it warms the clouds and the planet’s surface.

2. These warmed objects emit radiation back toward the atmosphere where it is absorbed by greenhouse gases.

3. The warmed greenhouse gases re-emit infrared radiation back toward Earth causing the surface to warm further.

What causes unequal heating of the Earth?

• the planet’s spherical shape

• the planet’s tilt on its axis

• and varying surface materials

What are the consequences of air and ocean currents?

Air currents

• Hadley cells

• Polar cells

• Trade winds

Ocean currents

• Gyres

• Upwelling

• El Niño southern oscillation