Populations

Question 1

Populations exhibit 5 unique characteristics that individuals do not:

Answer 1

1. geographic range
2. abundance
3. density
4. change in size
5. composition

Question 2

metapopulation=

Answer 2

a collection of separate (sub) populations of a species that interact to some degree (on their way to becoming separate species)

Question 3

The idea of metapopulations is broadly applied to species in _____ habitats

“a ___ of ____”

Answer 3

fragmented (naturally or artificially)

a population of a population

Question 4

range maps document:

Answer 4

the existence of species in space and time

Question 5

What are the 3 types of range maps?

Answer 5

• outline maps
• dot maps
• contour maps

Question 6

What is an outline map?

Answer 6

a hand-drawn range of a species; organism’s known habitat requirements/ ability to cross rivers etc is used to estimate its probable distribution

Question 7

____ maps serve as a basis for outline maps: points are plotted where a species has been ____

Answer 7

dot

recorded (seen)

Question 8

Give 1 advantage and 3 disadvantages of dot maps

Answer 8

advantage:
- accurately shows documents records of species distribution

disadvantages:
- sightings represent a small % of actual places where individuals live (present or past)
- do not make inferences about potential distribution of a species
- could be either under or overestimating range

Question 9

Hybrid Contour-dot maps=

Answer 9

a combination of dot and outline maps

= a free-form line drawn around recorded locations (dots) to estimate full range

This is the best representation of the expected distribution

Question 10

Contours on a contour map show:

Answer 10

similar levels of individuals or populations across a geographic range

Question 11

Disadvantages/ advantages of contour maps?

Answer 11

dis:
- usually based on sparse data, so interpret them cautiously
- much of the pattern is based on interpolation

ad:
- shows abundance!

Question 12

aerographic patterns=

Answer 12

ranges expand for species as you move away from the tropics

Question 13

At the equator, ___ limits dominate a species’ range, and towards the poles, ____ limits dominate

Answer 13

biotic (eg competition)

physical (less resources + harsher temps)

Question 14

Disturbances can be natural or man-made. Give up to 5 examples

Answer 14

fire
hurricanes
tornados
volcanic eruptions
human developments

Question 15

Disturbances can either limit or expand a species’ range. Give an example of each

Answer 15

Limit: cold weather prevents expansion of mtn pine beetles

Expand: fires have allowed the expansion of shrubs and trees onto prairies

Question 16

Abrupt boundaries=

give eg

Answer 16

can include climatic variables such as precip, wind, temp

eg. random group of trees living in the middle of nowhere

Question 17

Liebig’s Law of the Minimum=

Answer 17

populations are limited by the single resource that was most scarce relative to demand

ie a pop increases until the supply of the most limiting resource prevents is from increasing further

Question 18

t/f

limiting resources are always abiotic & that’s the resource that will regulate the growth of a population

Answer 18

false

can be abiotic or biotic

they do regulate growth of pop

Question 19

Give up to 4 examples of biotic factors that influence species composition and range distribution

Answer 19

symbiotic relationships
competition
herbivory
predation

Question 20

commensalism=

Answer 20

2 species live in close association and one species receives a benefit, while the other experiences neither a benefit or cost

(+ and neutral)

Question 21

Parasitism=

Answer 21

one organism (parasite) causes harm to the other (the host).

(- and +)

Question 22

Parasites are organisms that live on (____) or in (____) another organism

Answer 22

on= ectoparasites
in= endoparasites

Question 23

Individual parasites usually eventually kill their host

Answer 23

false; that’s not in their best interest because then they don’t have a host!

However, some hosts die when they’re infected by a large # of parasites

Question 24

When a parasite causes a disease, it’s called a _____

Answer 24

pathogen

eg. bacteria, viruses, fungi, etc

Question 25

mutualism=

Answer 25

2 species interact in a way such that each species benefits from the other (+ and +)

eg. coral and dinoflagellates

Question 26

Competition=

Answer 26

an interaction b/w organisms or species in which both require a resource that is in limited supply

Question 27

Interspecific competition=

Answer 27

competition b/w individuals or different species

Question 28

Intraspecific competition =

Answer 28

competition b/w individuals of the same species

Question 29

How does the black walnut tree deal with competition?

Answer 29

produces an aromatic organic compound that leaches into the soil and makes it hard for other species to grow close by

prevents other organisms from living around it= it guarantees the resources near to it

Question 30

t/f

competition can be a mutually detrimental interaction for all parties

Answer 30

true

Question 31

Exploitative competition=

Answer 31

individuals use up resources andmake them unavailable to others

Question 32

Interference Competition=

Answer 32

individuals use aggressive dominance or active inhibition to deny other individuals access to resources

ie the resources are there, just prevented from using them

eg lions defending their territory

Question 33

competitive exclusion principle=

Answer 33

when 2 species are limited by the same resource, one species is better at obtaining the resource or is better able to survive when the resource is scarce

Question 34

Why do we see sharp boundaries between closely related species?
ie non-overlapping ranges

Answer 34

because of the competitive exclusion principle!

One species persists, & the other dies out or has to move ranges

Question 35

Two species cannot coexist in the same ecological niche for long w/o one becoming extinct or being driven out b/c of comp for limited resources.

What does this describe?

Answer 35

competitive exclusion

Question 36

Competitive exclusion suggests competition limits ______ by preventing __-______

BUT there is no direct evidence of competition occurring on the _____, so there could be alternative explanations to the distributions

Answer 36

distribution

co-existence

boundaries

Question 37

Predation=

Answer 37

the ecological process by which energy is transferred from living animal to living animal based on the behavior of a predator that captures & kills a prey before eating it

Question 38

paraitoids=

Answer 38

a type of predator
- lay their eggs on/ in other animals & the eggs hatch into larvae that consume the host from the inside
- usually wasps or flies
- mix b/w parasite and predator

Question 39

Herbivory=
the feeding on living ___ parts by organisms. Typically only a small portion is consumed and it’s not ____

Answer 39

plant

killed

Question 40

The most competitive plants are often the most susceptible to ___

Answer 40

herbivores

= trade-off!

Question 41

the most competitive animals are typically the most susceptible to ____

Answer 41

predators (b/c most attractive)

= trade-off!

Question 42

Habitat=

Answer 42

physical place that an organism lives
- distinguished by physical features, often including the dominant species of plant or animal life
- habitats often overlap with each other

Question 43

niche=

Answer 43

includes the range of abiotic and biotic conditions it can tolerate
-each species has a distinct niche
- no 2 species have exactly the same niche

Question 44

Fundamental niche=

Answer 44

the range of abiotic conditions that an organism can survive in theoretically (usually very large range)

Question 45

Realized Niche=

Answer 45

the range of abiotic and biotic conditions an organism actually lives in (optimal range)

Question 46

T/F

Although a species can potentially live under the conditions of its fundamental niche, many favorable locations remain unoccupied.

Answer 46

true

due to competition, predators, pathogens, etc