BIOEE 1610 1st EditionExam # 1 Study Guide Lectures: 7 -152-24 (Populations)The hierarchical organization in ecology goes as follows: biosphere > ecosystem > community > population > organism. Population (a group of individual of the same species that live within a particular area and interact with each other) is the level we’re discussing here. Why do populations matter? Answer: population growth, immigration, and emigration (humans); management of exploited species; control of pests; conservation of endangered species. Populations can be defined in space in terms of abundance (number of individuals), density (number of individuals per unit area), dispersal (movement away from birthplace or away from areas of high population density), and migration (annual seasonal movement). A metapopulation is a group of spatially isolated populations that are connected by the flowof individuals and genes.There are three main types of distribution: 1) random, 2) clumped, and 3) regular. Factors limiting distribution can include temperature, water, acidic pH, abiotic factors, biotic interactions, disturbances, and historical factors. A life table is a summary of age specific survival and mortality in a population. To use these, you must have some way of knowing the age of an individual at the time of their death (fish scales, growth rings on trees, tooth wear). Life tables can be used to create survivorship curves, which can be type I, II, or III, classified by which life stage mortality is most likely to occur. A cohort life table follows a group of individuals born at the same time, whereas a static life table is a snapshot of age distribution at a moment and assuming age-dependent mortality. Survivorship curvesType IType IIType III2-26 (Life histories and life tables)A life history is the pattern of an organism’s time/energy invested into growth, survival, and reproduction. In general, females in particular have limited resources and natural selection works to optimize how these resources are spent. Trade-offs: reproduce once or many times, produce many small weak offspring or few large strong offspring, reproduce early (hence many times) or late (but higher quality). Investments include time, energy, resources, and parental care. Successful life history strategies include iteroparity (reproducing over and over like an oak tree), and semelparity (one reproductive eventThese 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.like a salmon). These are favored depending on the presence of predators and the annual patterns of food availability. Reproductive patterns are classified by number of reproductive cycles, number of offspring, amount of parental care, and sexual vs asexual.Life tables can be used for more than just survivorship curves. Fecundity can be combined with survivorship to estimate net reproductive rate. Population growth can be geometric (looks like an exponential graph, except that there are defined periods of reproduction rather than constant reproduction), exponential, and sigmoidal/logistic.3-3 (Competition)Review: r-selected species (insects, mice) live fast and die young while K-selected species (large reptiles, humans) live slow and steady. There a several types of species interactions, one being competition. Competition can be intraspecific (between member s of the same species) or interspecific (between members of different species). It can also be exploitative (where the use of a resource by one individual limits its availability to other individuals) or interference (where there is direct competition for access to the resource). A niche is the range of environmental conditions and resources within which individuals of a species grow, thrive, and reproduce. They can be wider for some and narrower for others, and quite often overlap with other species, leading to competition. In Gauss’s experiments, he found that certain microbe species grown apart do very well, but when grown together, one gets outcompeted. Here’s a different example: in certain plots, ants and rodents competed for seeds. When the rodents were removed, ant populations increased. However, when ants were removed, rodent population did not really change much. The two have asymmetrical competition.In many cases, competition of the past has made organisms evolve so there is less competition today. Here is some of our evidence: 1) allopatric distribution (ecologically-related species living in geographic ranges that do not overlap), 2) resource partitioning (using different parts of a resource or using it a different times of the day/year), and 3) character displacement (niches diverge only in areas where their ranges overlap.3-5 (Exploitative interactions)Exploitative interactions are interactions in which one individual benefits at the cost of another. This includes predation (in which a heterotrophic organism [typically an animal] kills and consumes another), herbivory (in which a heterotrophic organism eats part or all of a plant [includes grazers, browsers, and phloem feeders]), and parasitism (in which an organism lives in or on a host, typically reducing its fitness). These types of interactions can be classified based on intimacy and lethality. Prey has evolved a number of ways to defend themselves from predation. These include: 1) size refuge (they can’t be easily consumed once they get too big), 2) crypsis (or camouflage against a background), 3) chemical defenses, 4) aposematic or warning coloration (bright colors to signify toxicity or bad taste), and 5) behavioral avoidance. Herbivory is a low intimacy and low lethality type of exploitative interaction, and herbivores tendto be very specialized in the type and part of the plant they consume, partially because of the extremely different nitrogen stored in different parts of plants. Like prey, plants have their own defense mechanisms: 1) physical defenses (spines, thorns, sticky sap, trichomes), 2) chemical defenses, 3)constitutive defenses (defenses that are always there), and 4) induced defenses (produced in response toherbivory or predation)Symbiosis is an association in which one organism lives in or on another (like parasitism). A disease is defined as the reaction of a host to a parasitic infection. Parasites are very successful… in fact there are more known parasite species than non-parasite species, and they are present most