Let’s Start …take handout, complete Do Now: pass up HW 1. Define predator, prey, parasite Essential Question: Explain how evolution shapes the interactions among species in an ecosystem Goal: interdependence of organisms

Anticipatory Set: Why are weasels so important?

Anticipatory Set: In most animal stories…..weasels are notorious fiends that randomly kill all the gentle creatures of their community. People who are dishonest are often called weasels. The fact is that weasels are predators of rats and mice. Why are weasels so important?

Community Ecology Species Interactions Chapt 21 lab chapt 27 honors

Zebra Mussels on a Crayfish! Brainstorm: What type of relationship do you think these two organisms have? explain

Symbiosis A relationship between different species living in close association with one another!

5 Major Types of Symbiosis 1. predation 2. parasitism 3. competition 4. mutualism 5. commensalism

Predation Predator ?? Prey ??

Mimicry Deception, when a harmless species resembles a poisonous or distasteful species!

Plant-Herbivore Interaction Secondary compounds – when chemicals are synthesized from products of their metabolism that are poisonous, irritiating, or bad tasting. Tobacco plants contain Nicotine which is Poisonous to insects! - Poison Ivy (ex)

Parasitism : One benefits & one is harmed! 6 day old Purple Martin covered in blowfly parasites Host parasite

Parasitism One benefits & one is harmed! Elephantitis - caused by 3 specific kinds of parasitic round worms

Parasitism Tapeworm!

Parasitism Bot Fly larvae

Parasitism Removal of the bot fly larvae

2 Kinds of Parasites Ectoparasites – external parasites, they live on their host but do not enter the hosts’s body ex: ticks, fleas, lice, leeches, mosiquitoes Endoparasites – internal parasites, live inside the host’s body ex: malaria parasites, tapeworms

The objective of the study was to determine the utility of leech therapy in venous congested microvascular free flaps in which venous outflow could not be established or surgical revision was unsuccessful. LEECH THERAPY!

Competition 1. competitive exclusion : one species is elliminatted from a community because of competition for the same limited resources 2. resource partintioning : competition is most intense between closely related species that require same resources, each species uses only part of available resources

Continue…… 3. Character Displacement : competitors may also evolve niche differences or anatomical difference that lessen the intensity of competition ex: Darwin’s finches!

Niche Habitat It’s way of life, role species plays in it’s envir. Includes range of conditions that species can tolerate, the methods by which it obtains food needed, resources the no. of offspring it has it’s time of reproduction and all of its other interactions with it’s envir. The physical area which an organism lives.

Mutualism and Commensalism Mutualism: both species derive some benefit ex: pollinators! Commensalism : one species benefits and the other is not affected. ex: barnacles that attach themselves to whales!

Mutualism

Commensalism

Succession the gradual sequential regrowth of species in an area Primary succession: development of a community in an area that has not supported life previously such as bare rock, sand dunes or island formed by volcanic eruption. Secondary succession: replacement of species that follows disruption of an existing community.

Pioneer Species : small, fast growing and fast reproducing (first to appear)

Climax community traditional description of succession is that the community proceeds through a predictable series of stages unitl it reaches a stable end point