Midterm 1 Material

Question 1

Define environment

Answer 1

External factors that influence survival, growth and/reproduction

Question 2

Define relationships

Answer 2

– Interactions with physical aspects of
environment
– Interactions with same and other species

Question 3

Abiotic or biotic environmental factors can be classified as

Answer 3

– Resources: can be consumed thus making them less available for others (e.g., food, water, and mates)
– Conditions: can influence an organism but can not be consumed (e.g., temperature, day length, or acidity), including some hazards

Question 4

What are the four main principles to the theory of evolution?

Answer 4

Variation, overproduction, adaptation, descent with modification (over time there will be more individuals with that trait, and the species will be changing.)

Question 5

Define ecosystem and what makes up an ecosystem

Answer 5

An environment in which organisms carry out their “struggle for existence”, and at the same time are altered by the individuals within it. Made up of biotic and abiotic factors

Question 6

What kind of affect does trophic downgrading have on an ecosystem?

Answer 6

Trophic downgrading leads to drastic changes in which you see less diversity. Some of the changes include, large predators are absent, small predators dominate. Lower songbird density. Numerous large herbivores.

Question 7

What is the ecological hierarchy?

Answer 7

Individual — population — community — ecosystem — landscape — biome — biosphere

Question 8

Define population

Answer 8

a group of individuals of the same species that occupy a given area. Populations within a population compete for resources, have predator - prey relationships, as well as mutually beneficial relationships

Question 9

Define community

Answer 9

all populations of different species interacting within an ecosystem

Question 10

Define landscape

Answer 10

The area of land or water that is composed of different communities and ecosystems

Question 11

Define Biomes

Answer 11

Geographic regions with similar geological and climatic conditions ex: boreal forest, aspen parkland, grasslands

Question 12

What is the most difficult thing about doing field experiments?

Answer 12

Difficult to control other influencing factors

Question 13

What is a main flaw in a lab experiment

Answer 13

Results are not directly applicable in the field

Question 14

Define life history

Answer 14

The lifetime pattern of growth, development, and reproduction

Question 15

What is the difference between monogamy and polygamy, and within that define polygyny and polyandry

Answer 15

Monogamy involves single relationships between one female and one male, while polygamy involves an individual having more than one mate. Polygyny is a single male mates with many females (more common) and Polyandry is a female mating with many males.

Question 16

Where is monogamy more common?

Answer 16

In species where parental cooperation is critical, most common in birds and less common in mammals.

Question 17

Which is more common in mammals polygyny or polyandry?

Answer 17

Polygyny

Question 18

What are the three birds do Polyandry?

Answer 18

The jacanas, phalaropes, sandpipers.

Question 19

Define Intrasexual selection

Answer 19

Involves same-sex competition among polyandrous species, always male-to-male or female-to-female

Question 20

Define intersexual selection

Answer 20

Competition within the species that involves differential attractive traits. For example, think of finch beak examples or peacock examples. Better and worse attributes.

Question 21

Define Sexual dimorphism

Answer 21

The combination of intrasexual and intersexual selection of a species

Question 22

Define reproductive effort

Answer 22

The time and energy allocated for reproduction,within this there are trade offs between maintenance, growth, and defence compared to reproduction. It is a negative relationship

Question 23

Why does natural selection favour individuals that produce the maximum number of reproducing offspring in a lifetime?

Answer 23

Because the species can replace themselves quickly and grow at a faster rate than that of species that cannot reproduce often.

Question 24

Define Precocial and Altricial

Answer 24

Precocial individuals are very motile soon after birth, while altricial need continuous parental support to inactive offspring, often blind too.

Question 25

How does being able to reproduce affect your survival rate?

Answer 25

Consistently we see that species that are at their highest offspring yield also have a higher mortality rate

Question 26

What is the difference between semelparous vs Iteroparous organisms?

Answer 26

Semelparous reproduce all at once in a suicidal attempt, while iteroparous reproduce many times throughout the lifespan of the individual.

Question 27

What is the consequence of being able to reproduce sooner/later?

Answer 27

If you can reproduce sooner, there is a higher chance that you will die earlier in life, while the opposite happens if you reproduce later.

Question 28

What does the Balanus and Chthalamus intertidal example tell us?

Answer 28

Competition yields ecological niches. The chthalamus can out compete Balanus at the top of the coast but not at the bottom.

Question 29

Define abundance

Answer 29

the number of individuals in the population and defines its size, it is a function of population density. So the abundance of grizzly bears could just be northern western Canada for example, while the population would take a sample of this

Question 30

Define ecological density

Answer 30

Number of individuals per unit of available living space.

Question 31

What are the three population distribution patterns?

Answer 31

Random, uniform, clumped.

Question 32

What is the formula for population size

Answer 32

Density x area. Often times population density must be estimated by sampling a portion.

Question 33

What is the formula used in the capture-recapture method?

Answer 33

N= Mn/R
M— original captured
N—recaptured individuals
R— marked individuals of the recaptured sample

Question 34

Define philopatric

Answer 34

Individuals that habitually return to the same location or stay in place, more often found in females.

Question 35

Define cohort

Answer 35

A group of individuals born in the same period of time

Question 36

What are the three types of survivorship curves?

Answer 36

Type 1, 2, 3.
1– typical for individuals with long life spans, heavy mortality at the end.
2– survival rates do not vary with age (adult birds, rodents, reptiles, perennial plants).
3– Mortality rates are extremely high early in life (fish, invertebrate, plants)

Question 37

Define generation time

Answer 37

The mean time between when female is born and when she reproduces

Question 38

What is the difference between exploitation competition and interference competition?

Answer 38

Exploitation— individuals indirectly interact with one another but affect the availability of shared resources.
Interference— results when individuals directly interact and prevent others from occupying a habitat or accessing resources within it.

Question 39

What is the difference between demographic stochasticity and environmental stochasticity?

Answer 39

Demographic stochasticity— the random variations in birth and death rates from year to year
Environmental stochasticity— the random variations in the environment or the occurrence of natural disasters

Question 40

What is the difference between extinction and extirpation?

Answer 40

Extinction— total loss of a species overall

Extirpation— local extinction/loss of a species population, one area only

Question 41

What are a few common reasons for population extirpation?

Answer 41

Introduction of a new predator, competitor, or parasite, habitat loss, small population size (inbreeding becomes common).

Question 42

What is the Allee effect?

Answer 42

The decline in reproduction or survival under conditions of low population density. This is due to less genetic variation and less females in the population.

Question 43

Define Detritivory?

Answer 43

An organism that is important for nutrient cycling and community dynamics

Question 44

Define Interspecific competition

Answer 44

Competition between different species in an ecosystem for the struggle of existence, constant arms race. It is a relationship that affects the populations of two or more species adversely.

Question 45

Define intraspecific competition and what two forms does it have?

Answer 45

The same relationship as inter, but occurs among individuals of the same species.
Exploitation— competition occurs when species indirectly interact with one another
Interference— competition results when species directly interact with one another occupying a habitat or accessing resources within it

Question 46

Why can’t complete competitions coexist?

Answer 46

If one competitor increases its speed then they will outcompete the other competitor driving it to extinction. Complete competitors are two species that live in the same place and have exactly the same ecological requirements, many studies done in a petri dish.

Question 47

What was Hutchinson’s niche concept?

Answer 47

That a niche is depicted in three-dimensional space, space is not exclusively physical, but may include non-physical factors such as light, pH and temperature. This is why one habitat can support many niches.

Question 48

What was the difference between Charles Elton’s definition of a niche and Hutchinson’s?

Answer 48

Elton’s niche suggested that species-environment interactions are two sided and that a species has an effect on its environment as much or more than its response to its environment

Question 49

What are the two types of niches and define them.

Answer 49

Fundamental niche— the niche that a species would have if no competition exists, its full range of survival under conditions.
Realized niche— the niche that a species claims after interspecific competition has affected its fundamental niche, the portion of the niche that the species actually exploits.

Question 50

How does resource partitioning usually happen between coexisting species?

Answer 50

Different kinds/sites of food, feeding at different times, foraging in different areas, exploiting the portion of resources unavailable to others.

Question 51

Define character displacement

Answer 51

A shift in feeding niche that subsequently affects a species morphology, behaviour, or physiology.

Question 52

What is the difference between functional response and numerical response?

Answer 52

Functional— The greater the number of prey, the more the predator eats. Represented as number of prey consumed per unit time.
Numerical— an increased consumption of prey that results in an increase of predator reproduction (same capita)

Question 53

What are some factors that affect a predators functional response?

Answer 53

Predator time budgets related to chasing, killing, eating, and digesting prey. Predator search images and prey switching. Ex: remember the wolf example where the development of roads helped wolves determine territories faster and actually decreased the time it took to hunt.

Question 54

What are the three types of prey consumption / prey population charts (sigmoidal type responses)?

Answer 54

Type 1 response — animals are constantly searching / hunting, prey population size is linear and then immediately plateaus
Type 2 response — looks like a √ graph, prey population size decreases as more prey get consumed
Type 3 response — looks like an S, a logistic growth cure. Usually happens during prey switching, prey population size bubbles and then slowly decreases as predator is switching prey.

Question 55

Define the two types of switching for a sigmoidal III response

Answer 55

Search image — the ability of a predator to recognize a prey species will increase as the prey population size increases
Prey Switching — the acts of a predator turning to a more abundant alternate prey

Question 56

What is apparent competition?

Answer 56

An interaction of two prey species where the presence of one prey has a negative effect on the other, but not the other way around. Ex: moose attract wolves, if moose start to move into the same area as caribou, wolves will pillage caribou which cannot defend themselves.

Question 57

What is the Red Queen hypothesis?

Answer 57

For prey to avoid extinction at the hands of predators, they must evolve means of avoiding capture. Arms race

Question 58

What are some versions of defence for preys?

Answer 58

Chemical defences, colouration / aposematism, batesian / mullerian mimicry, structural defences, reproductive traits.

Question 59

What is the difference between batesian and mullerian mimicry?

Answer 59

Batesian mimicry is when prey mimic other specific species that they appear like, while mullerian mimicry try to copy patterns that are associated with other species.

Question 60

What is predator satiation and why is it effective?

Answer 60

It is when a species produce most of the offspring in a short period of time. It is effective because the species can protect each other in herds, may make it more difficult to find resources.