How Organisms Interact in Communities

ObjectivesDescribe coevolutionPredict how coevolution can affect

interactions between species Identify the distinguishing features of

symbiotic relationship

Interactions Among SpeciesSome interactions among species are the

result of a long evolutionary history is which many of the participants adjust to one another over time

Coevolution: back and forth evolutionary adjustments between interacting members of a community

Predators and Prey CoevolvePredation: the act of one organism killing

another for food Predator: the organism that captures the

preyPrey: the organism that gets captured

Predators and Prey CoevolveParasitism: one organism feeds on and

usually lives on or in another, typically larger organisms

They do not usually kill their prey (host) Depend on host for food and place to live and

for reproduction http://www.youtube.com/watch?v=vgkL8PulP

dE

Plant Defenses Against Herbivores Protect themselves with thorns, spines, and

prickles Chemical compounds that discourage

herbivores Secondary compounds: virtually all plants

contain these defensive compoundsAll plants make their own unique defense

chemical

How Herbivores Overcome Plant DefensesCertain herbivores are able to feed on plants

that are protected by chemical defenses Adaptations to these chemical defenses

Symbiotic SpeciesSymbiosis: two or more species live together

in a close, long-term association Symbiotic relationships can be:

Beneficial to both Benefit one organism and leave the other

harmed or unaffected

Mutualism Mutualism: symbiotic relationship in which

both participating species benefit Ex. Ants and aphids

CommensalismCommensalism:

symbiotic relationship in which one species benefits and the other is neither harmed nor helped Sea anemones and

clown fish

ReviewDescribe coevolutionPredict how coevolution can affect

interactions between species Identify the distinguishing features of

symbiotic relationship Symbiosis Mutualism Commensalism