BIOL 2140 1st EditionFinal Exam Study GuideUnit 1: Species Surface area to volume ratio: Key morphological factor in temperature tolerance . When the surface area is large compared to the volume (small/thin things), heat is gained and lost quickly because there is lots of surface area to gain and lose heat and relatively little volume to retain heat.Nitrogen wastes: Kidneys: urinary system, filter waste from the blood and control water balance, electrolyte concentration, and pH Bluegill (freshwater fish): especially dump water and retain salts. Eliminate nitrogen as toxic ammonia. Triggerfish (saltwater): especially retain water, dump salts. Eliminate nitrogen as toxic ammonia. Both fish balance water and salt concentrations based on the environmental conditions. Kangaroo rat: especially retain water, dump super concentrated salts. Eliminate nitrogen as less toxic urea. Land animals- must get rid of nitrogen but without losing too much water. Therefore, land animals excrete highly concentrated nitrogen as less toxic urea. Phenotypic plasticity: Populations will harbor variation. Phenotypic plasticity deals with the a bility of an organism to change its phenotype in response to changes in the environment. Not every organism of a given species will have the same plasticity since each will have different phenotypes. What makes the same species “different”? Different alleles in DNA, different combinations of alleles. Thisgives rise to genetic diversity and thus phenotypic diversity in a population. Therefore, some species mayshow higher phenotypic plasticity than other individuals in the species. Ecological niche: Includes the habitat (where the organism lives) and the role (what the organism does). There are two types of niches, one that is theoretical (fundamental niche) and one that is realized (the actual niche). Ecological envelopes are used in fundamental niches to keep a catalog of the conditions the organism is known to survive in. temperature and moisture are key factors in revealing the habitat conditions. Organisms can have a broad niche (generalist) or a narrow niche (specialist). The narrower the niche the smaller the tolerance limits the less likely the species will be able to survive change. Optimal range of survival:The optimal range of survival varies among species and from organism to organism within a species. The tolerance limits of the young are much narrower than of the adults. Why? The young lack certain characteristics the adults may already have. Example, behavioral (learn to avoid predators).The young are more susceptible to harm. Population distributions: Most populations are distributed in a mix of patterns. They may cover patches or clumps of an area. Sympatric populations- share the same area Allopatric populations- occupy entirely separate regions—not adjacent or overlappingParapatric populations- adjacent to each otherClumps- happen when there is a lack of dispersal during reproductionJ-shaped curve-unchecked continuous growth. Human growth shows classic exponential growth. However it isn’t realistic due to environmental factors that curb the growth. Therefore the J shaped curve then becomes S shaped (sigmoidal). This is the logistic growth. The environment will always have an effect on population growth and growth cannot reach maximum possible rates. Social behavior: Sometimes species work together to ensure better survival (safety in numbers) but this can also cause competition for resources. Territoriality-species will defend an area from other competitorsDominance hierarchy-sharing an area, but not equally. Cooperation- individuals work to mutual benefit Altruism- one individual works to benefit another Cooperation and altruism are promoted/ reinforced by kin selection Selfishness- one individual works to own benefit, to the cost of another Spitefulness- one individual works at the cost of both. Ecology: Ecology- the branch of science that deals with how organisms interact with each other and their environments. (Includes biotic and abiotic things) Environmental science- the branch of science that focuses specifically on how humans interact with the natural world. Both are related, but environmental science considers human interest. Environmentalist- an ideology that values the protection of the natural world for its own sake, as a matter of principle or ethics. It is not considered science Ecology is considered a soft science because it involves uncertainties. Defining a species: Morphospecies concept: a group of organisms that look the same. (shape, size, color) works by groupingand separating organisms based on morphological similarity vs differences , eventually you cannot keep splitting them. However…Can a given species look morphologically diverse? Yes (dogs vary in size)Can different species look very similar? Yes (bees and wasps look similar)Biological species concept: a group of organisms that can and does reproduce with each other successfully. Sometimes separate organisms do interbreed. Example: horse and donkeys= mules If organisms look very similar, they will always interbreed? False. Some organisms that seem like the same thing don’t interbreed for practical reasons. Asexual organisms can interbreed? False, asexual organisms self-reproduce. Phylogenetic species concept: basically a genetically distinct group of organisms (the tip of a branch on an evolutionary tree) -share the same evolutionary ancestry, but haven’t diverged since then. However: there is no natural, objective stopping point: you could continue splitting until each species is genetically unique. Phylogenic data is difficult to come by, There is no absolute definition for species!Unified species approach: a species is a “same type” of organism that can interbreed.What is considered for the ecology of the organism? Evolutionary history, gene flow, distributions, behaviors. Reasonable definition of species: a group of organisms that can interbreed naturally to produce viable, fully reproductive offspring, and/or which share sufficient characteristics (extremely genetically similar) **Counter-current exchange system: Sperm whale vs elephant seal Both live in cold water, have blubber, because of the cold environment they have countercurrent heat exchange to keep warm blood in core of body, seals cool off on land, air out flippers (behavioral) Both dive deep in water, requires high hemoglobin and myoglobin must have CO2 stores