Ecology and evolution of species Interactions Flashcards
Ecology
study of how organism relate to one anotherr and to their enviroments
community ecology
- Study of intercations between species withing a community
Biological communities
- Species that co-occur at any particular locality
- all fish species within a coral reef
- all fish species that interact with a specific species of coral
- all interacting species within a particular locality
Interaction within communities govern many …..
ecological and evolutionary process
Biological communities are…….
networks of interacting species
An organism…. will determine how (and if) it interacts with other organism
- niche
Ecological niche
Total of all the ways an organism uses the resources of its enviroment
Ecological niche
- Space Utilization
- food comsumption
- temperature
- appropiate condition for mating
- requirements for moisture and more
Tyepes of ecological niches
- Fundamental niche
- realized niche
Fundamental niche
- entire niche that a species is capable of using
Realized niche
- Actual set of enviromental conditions, presence or absence of other species, in which the species can establish a stable population
What limits a species ability to occupy its fundamental niche?
Abiotic factors
Abiotic factors
- Physical barriers
- climatic variables
- sufficient habitat/territory
Biotic factors
- species interactions
- ex: competition
predator
prey interactions strongly influence prey population dynamics
Predation
consuming of one organism by another
Prey populations can have explosions and crahes
- removal of predator ex. White- tailed deer in Eastern U.S
- Introduction of predator ex. Introduction of rats, fogds, cats on island
predator exerts strong selection pressure
on prey populations
Symbiosis refers to
any type of intomate and long-term interaction between 2 or more different species
Defined in 1879 by heinrich de bary as
” the living together of unlike organisms”
there are….. and …….. symbionts
- we are going to focus on……..
- Facultative & obligate
- obligate
why is predation not considered symbiosis?
Mutualism (+/+)
Benefits both species
- Plants & pollinators
- Endosymbiotic bacteria
- lichens
Mutualism (+/+)
Benefits both species
- Plants & pollinators
- Endosymbiotic bacteria
- lichens
Commensalism (+/0)
Entamoeba gingivalis
live in the oral cavity of humans- gin
PARASITISM (+/-)
- any organism in or on another organism (host) of a different specuesd,causes harm
- requires host for its survival and development
- takes some of hosts resources
Parasitism exists in all major groups of
eukaryotic organims
External parasites- Ectoparasites
- live on the external surfaces of the host
- Fleas
- Ticks
- lice
- mites
- monogeneans (plathyhelimnthes)
- often gave specialized morphology
usually have simple(er) lifecycles
- direct transmission
Internal parasites- Endoparasites
live inside the host
often higly specialized for a specific host
morphology may be simplified because of where it lives in its host
Parasitic worms (helminths)
- trematodes
- monogeneans
- cestodes
- nematodes
- aca
Endoparasites can have very complex life cycles
- Dicrocoelium dendriticum- trematode
- Flatworm lives in ants as an intermediate host with cattle as its definitive host
- To go from the ant to a herbivorus mammal, it changes the behavior of the ant
- causes the ant to climb to the top of a blade of grass to be eaten with the grass
Symbiotic interactions exist on a continuum acrross
ecological and evolutionary time
commensal E.coli in human intestines can become
pathogenic under certain condition
Species interactions can change over
evolutionary time
Ex. mutualist-
parasitic; commensal- mutualist
symbiotic intercations exist on a continuum across
- ecological and evolutionary time
- parasitism has evolved independently 223 times in Animalia (15 phyla)
All predictable species interactions have the potential for
coevolution
coevolution
is the reciprocal evolution between two species
- coevolution “arms race”
Coevolution in predator- prey systems
Plants adapt to predation (herbivory) by evolving mechanism
herbivory selcted for plant defenses= glucosinolates- herbivores sekect for being
Examples of coevolution: Flowering plants and insects
Sexual deceptive orchid genus ophrys
attraction of a pollinator is species specific
male insects think the orchid is a female
males able to learj individual flower patterns- remembered this pattern was unsuccessful
thus, avoid already visited ophrys flowe, interoreting them as females rejecting them
prevents the orchid’s self
Example of coevlution: Feather lice and Ptarmigans
- Ectoparasites often have dramatic coevolutionary signatures
- highly specialized morphology
- very narrow host range/ habitad
co-diversification-
Reciprocal splitting of two coevolving lineages
co-phylogenies
can be constructed to test fot concordance, or how closely the branching patterns match
