Exam 4 Study Guide
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This 6 page Study Guide was uploaded by Ally Bradfield on Friday April 29, 2016. The Study Guide belongs to 1020 at Auburn University taught by Dr. Zanzot in Fall 2015. Since its upload, it has received 11 views. For similar materials see Principles of Biology in Biology at Auburn University.
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Date Created: 04/29/16
Biology Unit 4 Test Study Guide Chapter 22: A Darwinian View of Life Darwin challenged previous views of unchanging species. For example, Aristotle believed that all species were unchanging and ranked on a hierarchical ladder of perfected species. The Old Testament believes that God put every species on the Earth as already perfect and unchanging. Important people: Linnaeus created taxonomy: the naming and classifying of species into categories by genus and species. Cuvier created paleontology: the study of fossils. He also created catastrophism: the difference between strata is caused by catastrophe. Hutton and Lyell both had a very important impact on Darwin’s theory. Hutton created gradualism: geological changes over time. Lyell created uniformitarianism: geological processes haven’t changed. Lamarck believed in Use & Disuse: vestigial structures no longer being necessary in evolved species so those parts are thrown out or stored. He also believes in evolution by acquired characteristics. Malthus focused on population growth with the exponential model. Wallace introduced Darwin to natural selection and studied biogeography. Darwin’s Views: Wrote a book called the Origin of Species by Means of Natural Selection. Evolution: descent by modification Observations 1. Members of a population often vary in inherited traits. 2. All species can produce more offspring than the environment can support but many fail to survive/reproduce. Inferences 1. Individuals that inherit traits have a higher chance of survival/reproduction than others. 2. The unequal ability of survival/reproduction will lead to more favorable traits over generations. Homology: shared ancestors but varied functions, same/similar structures Comparative embryology: homologies are only present before birth Analogy: similar structure from convergent evolution (independent), no shared ancestry Chapter 23: Evolution of Populations Microevolution Nonrandom factors: natural selection Random factors: genetic drift, gene flow *** IS NOT DRIVEN BY MICROEVOLUTION Macroevolution: patterns of evolutionary change above the species level Genetic variation enables evolution. Hardy-Weinburg Model/Equation Tests evolution in a population Gene maintained at HW equilibrium: 1. No mutations 2. Random mating 3. No gene flow 4. No genetic drift 5. No natural selection Natural selection: favorable inherited traits are more likely to survive/reproduce -leads to adaptive evolution by increasing the frequency of good alleles. Genetic Drift Founder Effect: population moves partially to a new location Genetic Bottleneck: population decreases by catastrophic event Most common in small populations. Leads to allele fixation (having only one allele for a gene) and loss in genetic diversity. Randomly changes allele frequencies. Gene Flow: spread of alleles within and to other populations, and random with different effects. ***NOT evidence for evolutkon Modes of Selection after Shift Directional: favors one extreme phenotypically Disruptive: favors both phenotypic extremes Stabilizing: favors middle variant Sexual selection -> mating success -> sexual dimorphism Diploidy (balancing selection) preserves genetic variation Chapter 24: The Origin of Species Speciation = new species = divergence of old species Biological species: group of populations that can interbreed and reproduce with each other not not successfully with other populations The Biological Species Concept (BSC) -> reproductive isolation, gene flow is required. Reproductive Isolation Pre-zygotic barriers: Habitat isolation- species live in a different place Temporal isolation- species breed at different times, seasons, etc. Gametic isolation- gametes come into contact but no fertilization takes place Behavioral isolation- species are capable of reproducing but don’t due to differences in mating techniques Mechanical isolation- incompatibility of structure of species to reproduce Post-zygotic barriers: Reduced hybrid variability Reduced hybrid fertility Hybrid breakdown Other concepts: morphological, ecological (species described by role in environment), and phylogenetic. Geographic Speciation Allopatic (other country, more common) Sympatric (same country) results from polyploidy, habitat differentiation, and sexual selection. The more barriers there are, the more biodiverse. Hybrid zones -> reproductive isolation Reinforcement of boundaries Stabilization of hybrid population Fusion of species Chapter 53: Introduction to Ecology and Population Ecology Ecology: study of interactions between organisms and the environment Biological processes influence population density, dispersion, and demographics (how populations change in character, track survival/reproduction and sexual equality. Also can produce a survivorship curve). Survivorship Curves Type I: death rate starts low and increases later in life Type II: consistent death rates Type III: many offspring die at first, few live on Exponential Model Zero population growth: birth and death rates are equal Change in population = growth rate x initial population Logistic Model Population growth slows when half of the carrying capacity is reached. Allee effect: when a population is too small to effectively survive/reproduce Natural selection produces life history traits: 1. Age of first reproduction 2. Number of times an organism reproduces 3. How many offspring are produced at a time Semelparous species: reproduce once with lots of offspring, often occurs in an unstable environment Iteroparous species: reproduce several times with fewer offspring, often occurs in a stable environment K-selection: density dependent, favors few, more offspring r-selection: density independent Density Dependent Factors -disease -predation -territoriality -competition -toxic waste -intrinsic factors (hormones) Chapter 54: Community Ecology Competition (-/-) species cannot coexist Predation (+/-) one kills another and eats it -predators develop claws, fangs, venom, etc. as adaptations -prey develop behavioral, mechanical, chemical, morphological, and physiological adaptations to avoid predation Herbivory (+/-) heterotroph kills and eats autotroph -autotrophs develop mechanical adaptations such as thorns, prickles, etc. and chemical adaptations such as toxic compounds Symbiosis: intimate, direct contact between species Parasitism (+/-) Mutualism (+/+) Commensalism (0/+) Facilitation (+/+) Mimickry -Batesian: harmless species mimics a harmful one -Mullerian: two harmful species mimic one another Character displacement: a tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric populations of the same two species Niche: a species occupation using abiotic and biotic resources -fundamental (potential) vs. realized (actual) niches Competitive exclusion: two species competing for the same limited resource cannot coexist in the same habitat Resource partitioning: differentiation of ecological niches such that similar species may coexist in a community IMPORTANT INFORMATION Law of superposition: states that old rock is on the bottom and new rock is on the top Cryptic coloration: Punctuated equilibrium: periods of apparent stasis marked by sudden change Gradual equilibrium: more gradual Viruses have the highest mutation rate (even over bacteria) Cline: gradual change in a trait along a geographical axis Hybrids usually suffer from alloploidy (different species) Autoploidy: own species Reinforcement: hybrids unequal to parent, low survival rate Fusion: fuses two species successfully Stability: hybrid is stable Random dispersion occurs in the absence of strong attractions or repulsion Clumped: attraction occurs Uniform: spread evenly Global -> Landscape -> Ecosystem -> Community
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