BIOL 301 1st EditionExam # 3 Study Guide Lectures: 12 - 16Lecture 12Species Interactions- Neutralism - No effect/insignificant effect interaction. Unlikely to exist, difficult to prove; scientifically uninteresting- Amensalism – No effect for one, negative effect for another- Commensalism - No effect for one, positive effect for another- Competition – Negative effect for both species- Mutualism – Beneficial for both species- Consumer-Resource interactions – Consumers abound. Predator, parasite, parasitoid, herbivore, detritivore.o Predator/Preyo Plant/Herbivoreo Parasitoid/Hosto Parasite/HostEffects of predators- Mesopredators: relatively small carnivores that consume herbivores (e.g., coyotes, weasels, feral cats).- Top predators: predators that typically consume both herbivores and predators (e.g., mountain lions, wolves, sharks). Humans have reduced or eliminated the world’s top predators, which has allowed many mesopredators to expand their geographic ranges. This has had dramatic effects on mesopredator prey populations.Population Cycles- The synchrony of population cycles between consumers and the populations they consume suggests that these oscillations are the result of interactions between them.Lecture 13Interactions - - Herbivore-Plant (Folivore, frugivore, granivore) (Grazers, browsers)- Predator-Prey (Insectivore, piscivore, avivore) (Carnivore)Resources – Any substance or factor that is both consumed by an organism and supports increased population growth rates as its availability increaseso Consumed, availability decreases o Used for maintenance and growtho Reduced availability reduces population growth- Limiting resource – a resource whose available quantity cannot meet a population’s requirement for itCycles – - Lotka-Volterra Predator/Prey model: a model of predator-prey interactions that incorporates oscillations in predator and prey populations and shows predator numbers lagging behind those of their prey.- Equilibrium (zero growth) isocline: the population size of one species that causes the population of another species to be stable. As the number of predators or prey changes and moves away from the equilibrium isoclines, populations will increase or decrease.- Joint population trajectory: the simultaneous trajectory of predator and prey populations.- Joint equilibrium point: the point at which the equilibrium isoclines for predator and prey populations cross.o If either of the populations stray from the equilibrium point, they will oscillate around the point.Responses – - Functional response: the relationship between the density of prey and an individual predator’s rate of food consumption.- Type I functional response: when a predator’s rate of prey consumption increases in a linearfashion with an increase in prey density. As prey density increases, predators consume a constant proportion of prey.- Type II functional response: when a predator’s rate of prey consumption begins to slow as prey density increases and then plateaus; often happens because predators must spend more time handling more prey or become satiated. Any increase in prey density is associated with a slowing rate of prey consumption.- Type III functional response: when a predator exhibits low, rapid, and slowing prey consumption under low, moderate, and high prey densities, respectively.- Low consumption at low prey densities may occur for three reasons: o 1. Prey can easily find refuges to hide.o 2. Predators may have less practice at locating and catching prey but develop a search image at higher prey densities.- Search image: a learned mental image that helps a predator locate and capture food.o 3. Predators may exhibit prey switching by changing their diet preferences to the more abundant prey.- Numerical response: a change in the number of predators through population growth or population movement due to immigration or emigration. Populations of predators usuallygrow slowly relative to populations of their prey, but the movement of mobile predators canoccur rapidly when prey density increases.Lecture 14Predation- Predators that exhibit active hunting strategies spend most of their time moving around looking for prey (e.g., birds foraging on lawns for worms).- Predators that exhibit ambush (sit-and-wait) hunting strategies lie in wait for a prey to pass by (e.g., chameleons waiting for insect prey).- Hunting can be thought of as a series of events, including detecting, pursuing, catching, handling, and consuming prey.- Prey have evolved numerous defenses to thwart predators at different points in this process.Defenses- Crypsis: camouflage that either allows an individual to match its environment or breaks up the outline of an individual to blend in better with the background (e.g., katydids, horned lizards). Structural defenses reduce a predator’s ability to capture, attack, or handle prey.- Warning coloration (aposematism): a strategy where distastefulness evolves in association with very conspicuous colors and patterns. Predators have innate aversions to aposematic colors; others learn to avoid certain colors and markings through experience.- Batesian mimicry: when palatable species evolve warning coloration that resembles unpalatable species (e.g., hover flies and hornet clearwings resemble the common wasp).- Müllerian mimicry: when several unpalatable species evolve a similar pattern of warning coloration (e.g., several species of poison dart frogs have evolved similar warning coloration).- Mullerian—unpalatable prey organisms adopt a single pattern of warning coloration- Batesian– palatable prey organisms resemble noxious ones- Selective pressure from herbivores has caused the evolution of plant defenses; some have phenotypically plastic defenses induced by attack, whereas others have fixed defenses.- Structural defenses (e.g., sharp spines, hair) deter herbivores from consuming leaves, stems,flowers, and fruits.- Some plants employ the strategy of tolerating herbivory and can rapidly replace tissues that are consumed, or grow more tissue in areas that are not being consumed.Costs of defenses- Behavioral defenses are often costly because they result in reduced feeding activity or crowding in locations away from predators. Mechanical defenses are often energetically expensive to produce. Defense costs can reduce growth, development, and reproduction.Coevolution-