Lecture 13: Communities: Competition & coexistence

Question 1

define parasitiods

Answer 1

“internal predators” that must kill their
host to complete their lifecycle

Question 2

define parasites

Answer 2

typically much smaller than their hosts and do not kill the host as part of their lifecycle (they “graze” the tissues of the host)

Question 3

define ectoparasites

Answer 3

parasites that live on the outside of a living host

Question 4

define endoparasites

Answer 4

parasites that live on the inside of their living host

Question 5

define transmission mode

Answer 5

• how a parasite finds its host
• can be highly variable, and alters
  the complexity of interactions

Question 6

parasite transmission - horizontal transmission

Answer 6

• movement of the parasite between individuals that are not parent and offspring
• can occur between members of the same or
  different species
• close physical contact is needed

Question 7

parasite transmission - Vertical transmission

Answer 7

movement of the parasite between host
parent and offspring.

Question 8

parasite transmission - vector

Answer 8

an organism that facilitates horizontal transmission, typically without suffering severe symptoms

Question 9

parasite transmission - Reservoir species

Answer 9

Species that can be infected with the parasite without any or severe symptoms, allowing the parasite to persist in a community outside of its primary host

Question 10

Pathogen

Answer 10

A microbial parasite that causes disease in its host

Question 11

how can the Lyme disease bacterial parasite be considered a pathogen

Answer 11

it causes some of its hosts to have a disease

Question 12

what is a stable product of antagonistic pathogen-host coevolution

Answer 12

Selection tending to produce low pathogen virulence and high host resistance

Question 13

Rabbits introduced into Australia exploded to a population size of _____

Answer 13

hundreds of millions

Question 14

Myxoma virus had______ — an ______ between pathogen and host

Answer 14

• mild effects in its natural host
• evolutionary stable state in the arms race

Question 15

define Kleptoparasitism

Answer 15

Direct theft of prey or other resources, resulting in a negative impact for the host

Question 16

broad definition of parasitic interactions

Answer 16

involves the consumption of host resources, resulting in a negative impact on the host.

Question 17

define Brood parasitism

Answer 17

Infiltration of host nests by the offspring of another species, exploiting parental care and resulting in a negative impact on the host and their offspring

Question 18

define mutualism

Answer 18

Reciprocal adaptations in two or more species that benefit all species.

Question 19

define symbiosis

Answer 19

• Any interaction where members of different species live in intimately connected interactions
• outcome of interaction can be highly variable.

Question 20

Mutualisms are an ______ between species

Answer 20

evolutionary collaboration

Question 21

what can mutualism often form between

Answer 21

consumer and resource species when both species offer services outside of consumer resource interaction and evolutionarily shift into a new category of species interaction

Question 22

how may mutualisms be actively maintained

Answer 22

selection exerted by third party resource species or consumer species

Question 23

define trophic mutualisms

Answer 23

Partners have complementary functions for obtaining energy and nutrients

Question 24

The_______ between leaf-cutting ants and fungus is _______

Answer 24

• trophic mutualism
• attacked by parasitic fungus

Question 25

Mutualism with ______ has also evolved to defend mutualistic fungus against the parasitic fungus invader - ______

Answer 25

• defensive bacteria
• defensive mutualism

Question 26

what are Defensive mutualisms

Answer 26

• Plant-ant mutualisms are one of the best studied defensive mutualisms.
• Plants provide shelter and/or food to attract resident ants, and ants defend the plants against herbivore enemies

Question 27

define dispersive mutualisms

Answer 27

• Plants get reproductive services, animals get food
• example: Pollination and seed dispersal

Question 28

What type of interaction exists between coral and reef fish?

Answer 28

• commensalism
• reef fish gets benefits from coral
• coral does not care about it and has no interaction with the fish
• coral – ecosystem engineer

Question 29

define Ecosystem engineer

Answer 29

An organism that causes state changes in the environment that subsequently serve as vital resources for other organisms

Question 30

The persistence of the _______ created by an ecosystem engineer seem to be critical in determining the level of influence this interaction has on a community

Answer 30

state changes

Question 31

ecosystem engineering - chemical

Answer 31

microbes and plants create chemical gradients

Question 32

ecosystem engineering - Bioturbulance

Answer 32

burrowing and digging organisms cause turnover of nutrients and create disturbed habitat types

Question 33

ecosystem engineer - light

Answer 33

organisms that alter light penetration and scatter

Question 34

ecosystem engineer - structural

Answer 34

alter the physical environment with structures that create habitat and resources

Question 35

define competition

Answer 35

• Use or defense of a resource that results in reduced availability of that resource for another organism
• a consumer-resource interaction with -/- consequences

Question 36

Indirect/exploitation competition

Answer 36

Competition without direct contact between consumers

Question 37

Direct/interference competition

Answer 37

Competition with direct contact between consumers in access to the resource