BIOL 112 1nd Edition Exam 1 Study Guide Lectures 1 10 Lecture 1 August 26 Darwin observed o Adaptation o Many shared characteristics o Rich diversity Gets back to the idea that different organisms are extremely well adapted to their environment Darwin formed his hypothesis after noticing 3 things o Organisms are well adapted to their environments adaptation o All organisms have some features in common shared characteristics o Many diverse forms that is driven by the need to adapt to specific environments diversity Darwin s origin of species theory of evolution o Descent with modification o Evolution descent with modification Mechanisms natural selection survival of the fittest Fittest biological organism s ability to survive and reproduce pass on its genes to the next generation Individuals selected based on their adaptation With natural selection occurring at every generation evolution Useful reading concepts 1 2 and 1 3 Campbell Darwin was not the first to think of evolution but was the first to come up with the mechanism supported by evidence o Has stood up to 150 years of experimental testing o Aristotle Scala Naturae organisms ordered in increasing complexity Organisms unchanging Views before Darwin o 1 Aristotle organisms are fixed no evolution Scala Naturae ordered in increasing complexity Lecture 2 August 30 o 2 Creation old testament organisms fixed no evolution Also came up with the idea that the Earth is relatively young This was a problem for Darwin as there was not enough time for evolution to occur with this theory o 3 Linnaeus organisms share characteristics Known as the father of taxonomy Groupings based on shared morphological characteristics Still use his classification strategy today Taxonomy domain kingdom phylum class order family genus species biggest smallest Linnaeus did NOT realize that shared characteristics shared an ancestry see fig 1 14 o 4 George Cuvier fossils the remains of extinct organisms Extinction not due to evolution but to catastrophes Local disasters flood organisms die fossils new populations would colonize the area No evolution organisms forms fixed just migration and reproduction Darwin interpreted fossils as evidence of evolution o 5 Hutton and Lyell the Earth is very old Hutton gradualism the sum of many small changes over time amounts to a profound change ex A species that looks nothing like what it looked like before Lyell uniformitarianism rate of geological change is very slow and therefore the Earth must be old Uniformitarianism uniform rate of change over time For Darwin Hutton s hypothesis is analogous to evolution in biology Lyell Earth was old enough for evolution to take place Lecture 3 August 30 o 6 Lamark proposed evolution occurred Correct that organisms adapt Incorrect about mechanism acquired characteristic could be passed on from generation to generation Problem that acquired or environmentally induced trait cannot be passed on Darwin went on the voyage of the Beagle o Spent 5 years collecting specimens and making observations o Very important stop Galapagos Islands volcanic islands that had recently formed Darwin observed Species adapted to specific island environments Distinct beak shapes suited to food source Species resembled mainland species o Hypothesis Ancestor from mainland Island specific species arose through natural selection and adaptation Came up with the idea of natural selection through the process of artificial selection a very common practice at the time Things needed for natural selection o Heritable variation is essential a variation genetically encoded in the DNA o Competition as all species over produce individuals compete for limited resources Lecture 4 September 2 A scientific theory that is based on physical phenomenon and causes and stands up to experimental tests o Also explains a lot of observations Natural selection in action o Fossils homology analogy biogeography Darwin s theory explained many observations o Natural selection in action ex Drug resistance fig 22 14 Methicillin resistance by S aureus Methicillin antibiotic blocks synthesis of the bacterial cell wall Resistance mutation are in the methicillin resistance gene S Aureus variation in sequence Fossils o Intermediate fossils can be explained in terms of descent with modification Ex Whales other cetaceans evolved from a terrestrial ancestor Fig 22 70 Archaeopteryx intermediate fossils birds evolved from reptilian ancestors Anatomical homology o Similar structures due to common ancestor although function can differ Ex Forelimbs of various vertebrates Fig 22 17 Many bones in common shape organization number o High degree of similarity between structures the organisms had a common ancestor who had those characteristics o Because characteristics come from a common ancestor homologous characteristics or an example of homology Homologous characteristics must have many points of similarity Molecular homology o Gene or protein sequences that are very similar between 2 species Ex Bacteria and us protein that carry out essential processes ex Metabolisms are very similar homology o Similar because bacteria and us inherited genes from a common ancestor Lecture 5 September 4 o Many points of similarity not always the same function adaptation IN common ancestor homologous characteristic o Darwin observed organisms share characteristics Proposed shared characteristics inherited from common ancestor If there are many shared characteristics homologous structure Analogy convergent evolution o Same adaptation to similar challenge adaptations have same function few other characteristics in common adaptation NOT in recent common ancestor analogous characteristic o Analogy aka homoplasy mold the same way o To distinguish from homology HOMOLOGY ANALOGY Many points of similarity Present in common ancestor Few points of similarity Fig 22 17 Not present in a common ancestor Biogeography o Distribution of species adaptation to their particular environment o Continental drift is a significant factor in determining mammalian biogeography o Answers why marsupials are predominantly found in Australia Marsupials isolated on Gonawana Island Australia Fig 25 14 Population genetics o Population smallest unit of evolution o Natural selection changes in allele frequency Allele variant of a gene Diploid inherits 2 alleles for every locus Genotype alleles for diploid ex PP Pp pp Phenotype visible characteristics produced by a genotype ex Purple color vs white color
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