BIOL 1108 1nd Edition Lecture 2 Outline of Last Lecture I. AbiogenesisA. Definition of abiogenesis- the study of how life on Earth might have emerged from non-lifeB. Earth formed about 4.4 billion years ago- Mantle is heated by radioactive decay in Earth’s core- Continental drift effects climateC. Earth’s Atmosphere- H2O vapor (80%), CO2 (10%), no free oxygenII. For Life to Form SpontaneouslyA. Formation of Organic MoleculesB. Stanley Miller ExperimentC. Deep Sea VentsOutline of Current Lecture I.In the News: Why have Liberian riot police and soldiers used scrap wood and barbedwire to seal off 50,000 people inside the West Point slum in the capital city of Monrovia?II.Scientific TheoriesA.Jan Baptista van HelmontB.Francesco RediIII.The earliest living entities on Earth utilized a simpler type of biochemistry than do today’s cells. A.ProtocellB.RNA moleculeIV.Last Universal Common AncestorA.Symbiosis= living togetherB.Bacterial Gene Exchange-TransformationThese 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.-Transduction-ConjugationV.Evolution is randomA.Evolution is the product of two opposing forces-Random-Non randomCurrent LectureAbiogenesis: is the study of how life on Earth might have come to be from nonliving thingsBiological Characteristics: Growth Metabolism: consuming, transforming and storing energy/mass; growing by absorbing and reorganizing mass; excreting waste Motion: either moving itself, or having internal motion Reproduction: the ability to create entities that are similar to, yet separate from, itself Response to stimuli: the ability to measure properties of its surrounding environment, and act upon certain conditions.DARWINIAN EVOLVUTION!Astrobiology: Addresses how life began and evolve, if life exist beyond Earth, and what the future of life holds.I. In the News: Why have Liberian riot police and soldiers used scrap wood and barbed wire to seal off 50,000 people inside the West Point slum in the capital city of Monrovia?A. Ebola- filovirus (RNA) helical, nonsegmented, single stranded - Engulfed by macrophages then replicates and infects immune systemsII. Scientific TheoriesA. Jan Baptista van Helmont- Dirty clothing + wheat + 21 days = miceB. Francesco Redi- Meat and Fly experiment: found that maggots appeared when meat was uncovered, allowing flies to lay eggs. Proved that flies, not direct meat, produced maggots.III. The earliest living entities on Earth utilized a simpler type of biochemistry than do today’s cells. A. Protocell- If RNA, ribozymes, and other premetabolic molecules were all contained within a lipid micelle the first “protocell” could evolve.- Chemical evolution led to the formation of protocells which led to the first ‘living” cellsB. RNA molecule- Polypeptides associating with RNA could aid in replication- RNA can store information and can act as an enzyme.- Theoretical evolution of self-replicating RNA- Self sustaining chemical reactions known as “hypercycles” result in complex products being formed provided there is an input of energyIV. Last Universal Common Ancestor A. Symbiosis= living together- Origin of first true cell via symbiosis of a consortium of protocellsB. Bacterial Gene Exchange- Transformation: genes from environment- Transduction: genes by way of viral transfer- Conjugation: genes transferred directly from one cell to anotherIV. Evolution is randomA. Evolution is the product of two opposing forces- Random: processes that constantly introduce variation in traitsEx. mutation- Non Random: processes that make particular variants become more commonor rareEx. Selection and genetic
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