Quiz 6 Study Guide: Evolution PDF

Quiz 6 Study Guide: Evolution The following is a list of topics to guide your studies. It may not be an exhaustive list. Class notes, homework assignments, and labs should all be studied. 1.​ History of Life a.​ The Fossil Record i.​ What is a fossil?...

Quiz 6 Study Guide: Evolution The following is a list of topics to guide your studies. It may not be an exhaustive list. Class notes, homework assignments, and labs should all be studied. 1.​ History of Life a.​ The Fossil Record i.​ What is a fossil? 1.​ Preserved evidence of an organism ii.​ Fossil formation through permineralization 1.​ Minerals seep into an organism’s remains and with the help of water solidify the organism iii.​ Understand why the fossil record is important and why it is incomplete. 1.​ Important because it allows us to trace back the history of life which then allows us to study the evolution of organisms iv.​ Factors that influence fossil formation 1.​ Decomposition: the breakdown of organic matter by microorganisms 2.​ Erosion: the wearing away of rock and soil by wind, water, or ice 3.​ Lack of hard parts: many organisms have soft bodies that do not fossilize well v.​ Relative Dating (Superposition) vs. Absolute Dating (Radiometric Dating) 1.​ Relative Dating: dating fossils based on the location of other fossils in comparison and the location of the strata layer a.​ Law of Superposition: The oldest rocks are buried beneath the youngest rocks, and the fossils found in each layer are older than those found in the layers above 2.​ Absolute dating: figuring out the exact date using radiometric dating or using radioactive isotopes a.​ Radiometric Dating: compares 2 radioactive isotopes to figure out how old the fossil is b.​ Geologic Time Scale i.​ Understand how the geologic time scale is broken up (epochs, periods, eras, eons). 1.​ Eons -> Eras -> Periods -> Epochs ii.​ Age of the Earth / when the first life forms appear in the fossil record 1.​ The Earth is about 4.6 billion years old but the first life didn’t appear until 3.5 billion years ago a.​ First life was photosynthetic prokaryotes iii.​ Know what started, ended, and occurred during each of the following divisions of the geologic timescale: -​ Precambrian (Hadean Eon, Archean Eon, Proterozoic Eon) -​ Hadean Eon -​ Start: formation of Earth -​ During: Very hot, volcanos, toxic gases, dark, molten land -​ Ended: The cooling of the Earth -​ Archean Eon -​ Start: Cooling of the Earth which brings water and land formed by previous liquid magma -​ During: Life emerges through photosynthetic prokaryotes -​ End: land starts to move and form supercontinents  -​ Proterozoic Eon -​ Start: The atmosphere is oxygenated -​ During: Ediacaran Period -​ Multicellular life emerges -​ Ends: Cambrian Explosion -​ Phanerozoic Eon (Paleozoic Era, Mesozoic Era, Cenozoic Era) -​ Paleozoic Era -​ Start: Cambrian Explosion -​ Explosion of life on Earth -​ The rapid diversification of life -​ During: Animals move to land -​ End: The Great Dying -​ Worst mass extinction -​ 70% of land animals and 96% of sea animals died -​ Likely caused because of an increase in volcanic activity due to climate change and changes in the ocean chemistry -​ Mesozoic Era -​ Start: The Great Dying -​ During: Age of Dinosaurs and complex life -​ End: The KT event -​ Caused by meteor impact -​ The meteor caused lots of debris that blocked the sun -​ Cenozoic Era -​ Start: The KT event -​ During: mammals diversify and humans evolve -​ End: present day iv.​ Understand the significance of the Cambrian explosion. 1.​ Cambrian Explosion a.​ A rapid growth and diversification of life on Earth b.​ The appearance of complex animals with mineralized remains i.​ Trilobites: early animals with exoskeletons that were used as index fossils ii.​ Fish: developed teeth and jaws and came to dominate the seas iii.​ Placoderms: armored giants that lived in the oceans iv.​ The first amphibians v.​ Understand the significance of mass extinctions. 2.​ Developing the Theory of Evolution a.​ What is the theory of evolution? i.​ All living organisms share a common ancestry and have evolved over time through natural selection b.​ Predominant European beliefs in the 1700’s - 1800’s i.​ Earth is about 6000 years old ii.​ Nothing changes in the environment iii.​ Species don’t change c.​ Know the contributions made by each of the following scientists to the development of the theory of evolution: i.​ Jean Baptiste Lamarck (Use and Disuse)  1.​ Principle of Use and Disuse: Traits that are used traits that are used develop and become stronger, while those that are not used weaken and disappear ii.​ Charles Darwin 1.​ Theory of Evolution and Natural Selection: Organisms with higher fitness are more likely to survive and reproduce d.​ Be able to define and apply the terms fitness, adaptation, and natural selection. i.​ Fitness: The ability to survive and reproduce ii.​ Adaptation: A trait that increases fitness iii.​ Natural selection: Organisms with higher fitness are more likely to survive and reproduce e.​ Four Principles of Natural Selection i.​ Variation: There must be variation in the population for natural selection to occur. ii.​ This variation can arise from mutations, which are changes in the DNA sequence of an organism. iii.​ Heritability: The traits must be heritable, meaning they can be passed on from one generation to the next. iv.​ Overproduction: There must be more offspring produced than can be supported by the available resources, leading to competition for resources. v.​ Reproductive Advantage: Some traits must confer a reproductive advantage, increasing an organism's chances of reproducing and passing on its genes to the next generation f.​ Microevolution vs. Macroevolution i.​ Micro 1.​ Change within a species 2.​ Webbing vs no webbing ii.​ Macro 1.​ Major changes over long periods of time 2.​ Transition from a historic-looking bird to a modern-day bird 3.​ Microevolution a.​ Mutations i.​ Mutation: produces a different version of a trait b.​ Natural Selection vs. Artificial Selection vs. Sexual Selection i.​ Natural Selection 1.​ Fitness decided by the environment 2.​ Ex. The ability to camouflage can increase and organism’s chance for survival ii.​ Artificial Selection 1.​ Fitness decided by humans 2.​ Ex. Breeding dogs to produce certain characteristics iii.​ Sexual Selection 1.​ Fitness decided by mates iv.​ Stabilizing vs. Directional vs. Disruptive Selection 1.​ Stabilizing: favors the average 2.​ Directional: favors one of the extremes 3.​ Disruptive: Favors both extremes c.​ Gene Flow i.​ Transfer of genetic material from one population to another (migrations) ii.​ Transfers genetic material from one population to another iii.​ Increases genetic diversity d.​ Genetic Drift i.​ A random process that results in the loss or gain of alleles in a population ii.​ Not based on fitness iii.​ Completely random iv.​ Often leads to a loss of genetic diversity v.​ Types of genetic drift 1.​ Bottleneck Effect a.​ a sudden reduction in population size i.​ Results in a loss of genetic variation ii.​ Caused by 1.​ Natural disasters 2.​ Predation events 3.​ Environmental factors 2.​ Founder Effect a.​ a new population is established by a small group of individuals i.​ Results in a loss of genetic variation vi.​ Driftworm Simulation Lab