BIOEE 1610 1st Edition Lecture 10Outline of previous lectureI. Mid-semester surveysII. ReviewIII. Species interactionsA) Types of species interactionsB) CompetitionC) NichesD) Studies and theoriesE) Two visions of competitionOutline of current lectureI. Exploitative interactionA) TypesB) PreyC) Parasitism and diseaseCurrent lectureI. Exploitative interactions*Benefits one individual at the expense of the other (predation, herbivory, parasitism)A) Types*Predation-A heterotrophic organism kills and consumes another-Usually an animal*Herbivory-A heterotrophic organism eats parts of or entire plants (grazers, browser, phloem feeder)-Smaller tends to mean more specialized*Parasitism-One organism lives in/on the tissue of its hosts, often reducing its host’s fitness-Example: Plasmodium (endoparasite), mosquitoes (ectoparasite) -Can kill its host-Parasitoids#Insect that lays one or a few eggs on or in a host organism, which consumes and kills the host#Invasion looks like parasitism, but functionally equivalent to predation*You can define exploitative interaction based on intimacy and lethality (predators are not These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.intimate but highly lethal, certain parasites are quite intimate but not lethal)B) Prey*Example  Brown Tree Snakes spreading though Guam, native bird species go down. In some places they went from 10 native bird species to 0. 7 bird species went extinct, 4 endangered, now snakes are declining due to food shortages*Size refuge: once organisms become a certain size, they can no longer be consumed*Crypsis: camouflage to the back ground*Chemical defenses: toxic spray, toxic bite, toxin skin secretions*Aposematic or warning coloration: bright colors to signal toxicity or bad taste*Behavioral avoidance: having predators around can make organism become less active or simply behave differently C) Herbivory*Low intimacy and low lethality (however, insect herbivores are closer to parasites) *Herbivore (especially insects) tend to be very specialized *The also tend to be specialized in terms of what part of the plant they eat*There is a difference in plant nutrients compared to animals-Animals have more nitrogen than all of plants-Seeds and leaves have more nitrogen than needles-Phloem sacs have very little nitrogen-This is why organisms specialize on so many different plant parts*Plants have defenses-Physical defenses (spines, thorns, hairs, sticky sap, toughness, trichomes)-Chemical defenses -Constitutive defense (a defense that is always present)-Induced defenses (a defense that is produced in response to herbivory or predation) This leads to grazed plants ending up with less damage than artificially damaged ones*Herbivores tend to have narrow diets in comparison to predators D) Parasitism and disease *Symbiosis: an intimate association between different species where one lives on or in another*Parasite: an organism living in or on another, called the host*Disease: the reaction of the host to a parasitic infection*Parasitism is extremely successful-We have more parasite species than non-parasite species-Mammals and trees have the highest average number of species of parasites per individual-We have them all over our body: lice, ticks, athletes foot, mouth bacteria etc*Parasites are classified by size, among other factors*Disadvantages to being ectoparasite: natural enemies, exposure to external environment, feeding is more difficult*Remember: not every bacterium inside of us is a parasite. They are all symbionts, butmany do nothing or even benefit us*Diversity of microparasites: bacteria, viruses, fungi, protozoans*Macroparasites: worms*Parasites can have some very complicated life cycles (lancet flukes are eaten by cattle, excreted, eaten by snails, passed as slime balls, eaten by ants, infect the ants brain so they cral tothe tip of a blade of grass, and then are again consumed by