Species Interactions & Species Diversity Flashcards
Community
An assemblage of species living in close enough proximity for potential interaction; has emergent properties: species diversity, tropic structure, stability over time
Interspecific interactions
Interactions between species; can be positive, negative or neutral; Competition (-/-), Exploitation (+/-), Mutualism (+/+), Commensalism (+/0)
Competition
An antagonistic interaction that occurs when species compete for a resource that limits survival and reproduction; resources must be in short supply for it to occur; mechanisms: exploitative or interference
Exploitative
An ecological interaction in which individuals of one species benefit by feeding on (and thereby harming) or using individuals of the other species. Exploitative interactions including predation, herbivory, and parasitism
Interference
Aggressive encounters among individuals shape resource access
Competitive exclusion
The concept that when populations of two similar species compete for the same limited resources, one population will use the resources more efficiently and have a reproductive advantage that will eventually lead to the elimination of the other population
Ecological niche
The sums of an organism’s use of biotic and abiotic resources; it can be thought if as an organism’s ecological role
Resource partitioning
Differentiation of ecological niches, enabling similar species to coexist in a community
Fundamental niche
The entire set of conditions under which a species can survive and reproduce itself (potentially)
Realized niche
The set of conditions actually used by given species, after interactions w/ the other species (predation and especially competition) have been taken into account
Character displacement
A tendency of characteristics to be more divergent in sympathetic populations of two species than in allopathic populations of the same species
Allopathy
The occurrence of populations of related organisms in separate, non-overlapping geographic areas such that members fail to encounter one another; ranges do not overlap
Sympatry
The term used to describe populations, varieties, or species that occur in the same place at the same time; ranges overlap (co-occur)
Interspecific competition can result in:
Exclusion
Resource partitioning
Character displacement
All of the above
All of the above
Predation
An antagonistic exploitative interaction (+/-) in which one species, the predator, kills and eats the other, the prey
Evolutionary arms race
An ongoing struggle between competing sets of co-evolving genes, phenotypic and behavioral traits that develop escalating adaptions and counter-adaptations against each other
Name examples of prey defense.
Mechanical defense (needles on a porcupine), Chemical defense (gas released by skunk), Aposematic coloration (warning coloration by a poison dart frog), Cryptic coloration (camouflage by canyon tree frog), Startle response (eyespots produced by a butterfly/moth), Misdirection (false heads by a butterfly?), Mimicry
Aposematic coloration
Anti predator adaptations where a warning signal is associated w/ the unprofitability of a prey to potential predators
Mimicry
The close resemblance of an organism (the mimic) to some diff. organism (the model) such that the mimic benefits from the mistaken identity; two types; Batesian and Müllerian Mimicry
Batesian mimicry
A type of mimicry in which a harmless species resembles an unpalatable or harmful species to which it is not closely related; Ex: coral snake (venomous) and milk snake (non venomous but looks like a coral snake)
Müllerian mimicry
Reciprocal mimicry by two unpalatable species; Ex: cuckoo bee and yellow jacket
What type of mimicry is this:
Nonvenomous hawkmoth larva snake and generous green parrot snake
Batesian mimicry
Predator-prey interactions can affect what?
Population dynamics of predator and prey, characteristics of predator and prey, and the growth rates of prey due to avoidance
Herbivory
An antagonistic exploitative interaction (+/-) in which an herbivore eats parts of a plant or alga; can be engaged in an evolutionary arms race
Parasitism
An antagonistic exploitative interaction (+/-) where one organism, the parasite, derives nourishment from another organism, it’s host, which is harmed in the process; can be engaged in an evolutionary arms race; has three types of parasites: endoparasite, ectoparasite, and parasitoids
Ectoparasite
Parasite that feeds on external surfaces of host
Endoparasite
Parasite that lives inside the host
Parasitoids
Parasite that lays eggs in host and will lead to death
Mutualism
Common Interspecific interaction that benefits both species (+/+); Ex: Acacia trees and ants, corals, sea anemones and clownfish, turtles and cleaner fish; two types: facultative and obligate
Facultative
Not necessary for survival of either species; Ex: legumes and nitrogen fixing bacteria
Obligate
Necessary for survival and reproduction of one or both species; Ex: lichen=fungi + algae
What type of mutualism are plant pollinator mutualisms?
Service-resource mutualisms where pollinators provide service and flowers provide resources; represents reciprocal exploitation as both species incur costs, but the benefit to each partner exceed the costs
Commensalism
An interaction in which one species benefits and the other is neither harmed nor helped (+/0); Ex: Bromeliads and trees
