Bioee 1610 1st Edition Lecture 11Outline of Last LectureI. Exploitative interactionA) TypesB) PreyC) Parasitism and diseaseOutline of Current LectureI. Parasitic organismsII. Fundamentals of positive interactionsIII. Types of mutualismCurrent Lecture*Differences between lecture and textbook-“Predation” broadly: exploitation-“True predators”: predators-“Grazers”: attach prey and consume only part-“Parasites”: organisms attack one or a few preyI. Parasitic organisms*Found in many groups: bacteria, viruses, fungi, protozoans, sporozoans, ciliates, worms, arthropods, vertebrates, plants*Can decimate populations (ex: Rinderpest virus was the scourge of European cattle, resulted in the first veterinary college in 1762, vaccine developed in 1950’s; as cattle were vaccinated, wildebeest numbers grew [concluded that wildebeest were spillover hosts, so the virus could not be sustained without the cattle])*Parasites can alter the morphology and reproduction of their hosts (ex: When Arabis flowers are infected by Puccinia fungus, pollinators do not pollinate the flower, but helps the fungus infect more plants)*Parasites can modify species interaction (ex: Adelina parasite changes the outcome of competition between flour beetles)*Parasites can alter ecological communities (Chestnut trees attacked by parasites, Red Oak increased, White Oak decreased, Red Maple increased, and other species increased… totally changed the pattern of competition in the entire ecosystem)II. Fundamentals of positive interactions*Commensalism : one party benefits, the other is neither benefited nor harmed*Mutualism: both parties benefit (example: coral and algae… polyps secrete skeletons of calcium carbonate; global warming causes polyps to expel their mutualists: coral bleaching)-Obligate: one species cannot exist without the other-Facultative: benefits both, but they can live without*Symbiosis: an intimate association between different organisms where one lives on or in the other (usually coevolved) *Mutualism examples:-Coral and algae… polyps secrete skeletons of calcium carbonate; global warming causes polyps to expel their mutualists: coral bleaching-Mycorrhiza fungi: improves plant access to nutrients and water, provides fungi with carbohydrates… if nutrients are abundant, Mycorrhiza is a parasiteIII. Types of mutualism*Trophic mutualism: partners specialize (example: fungi and leaf-cutter ants)*Defensive mutualism: species receive food or shelter from partners in return for defending partners against herbivores, predators, or parasites -Example: fish cleaning hippos-Example: Pseudomyrmex ants and swollen thorn Acacia (ants get shelter/food from plant, ants clear predators and protect from herbivores so the plant is benefited)*Dispersal mutualism-Pollination: animals transport pollen between flowers in return for rewards like nectar (example: female yucca and yucca moths [only yucca moths can pollinate these flowers, but the moths lay their eggs in the flowers])-Seed dispersal: animals move seeds around in return for the fruit (example: fruit-eating fish that move from rivers to flooded forests)*Interaction between cattails and forget-me-nots (cattails are overall better off when forget-me-nots are around). What kind of interaction could this be?A) MutualistsB) CompetitorsC) Commensals-Answer: Either A or C (we’d need to know how the interaction works the other way