Book Notes - Chapter 1 Evolution > to unfold or unroll...

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Chapter 1 Evolution > “to unfold or unroll” Biological evolution > change in the properties of groups of organisms over the course of generations Individual organisms do not evolve > populations do descent with modification Staphylococcus aureus > now immune to penicillin Gonorrhea > more prevalent HIV > from chimps and mangabey monkeys to humans Plato > eidos > form or idea > a transcendent ideal form imperfectly imitated by others earthly representations > essentialism > variation is accidental imperfection > triangles and horses example Aristotle > species have fixed properties > Great Chains of Being > scala naturae Linnaeus > systema Naturae > relatedness Uniformitarianism > James Hutton and Charles Lyell > holding that the same processes operated in the past as in the present > the observations of geology should therefore be explained by causes that we can now observe Lamarck > Philsophie Zoologique > proposed that each species originated individually by spontaneous generation from nonliving matter, starting at the bottom of the chain of being. A nervous fluid acts within each species, he said, causing it to progress up the chain. Species originated at different times, so we now see a hierarchy of species because they differ in age > inheritance of acquired traits In Lamarck’s scheme, species have not originated from common ancestors This could happen to any and all giraffes, so the entire species could have acquired longer necks because it was composed of individual organisms that changed during their life times. Origin of Species and Descent of Man The Origin of Species has two points > descent with modification (all species have descended without interruption from one or a few original forms of life) > other point was natural selection This theory is a variational theory of change, differing from Lamarck’s transformational theory, in which individual organisms change
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Figure 1.4 Read Five Theories on 8 > change over time > common descent > gradualism (or saltations) > population change (changes in proportions) > natural selection (changes result in adaptations) Probems > variation should decrease according to blending hypothesis Neo-Lamarckism > modifications due to effect of environment on development > like plants with thicker leaves Orthogensis > straight line evolution > fixed goal Mutationism > mutant forms constituted new species > natural selection not necessary to account for origin of species Modern Synthesis Mutation, recombination, natural selection, and other process operating within species ( microevolution ) account for the origin of new species and for the major, long-term features of evolution (termed macroevolution ) Read the 16 points > acquired characteristics are not inherited > evolutionary change is a population process > rate of mutation is too low to shift population > instead, genetic drift and natural selection Molecular evolution (analyses of the processes and history of change in genes) in which the natural theory of molecular evolution > this hypothesis developed y Motoo Kimura
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This note was uploaded on 10/28/2008 for the course BIOEE 2070 taught by Professor Provine,w. during the Fall '07 term at Cornell.

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Book Notes - Chapter 1 Evolution > to unfold or unroll...

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