BSC 2011 UNIT III STUDY GUIDE PART A UNIT III Evolution and Population Genetics 1 Discuss the following various views people held about life s diversity how it arose and the age of the earth old young before evolution was suggested a essentialism idealism Plato is an Essentialist God created all things All things have a constant perfect essence ideal form Variation is and imperfect reflection of the inner essence No potential life was left unrealized species don t change no new species Aristotle and the Scala of Nature Scale of Nature All living things are fixed in a linear hierarchy Nothing was left out of the hierarchy a k a species can t won t and shouldn t change b natural theology Natural Theologians monotheistic Western Christians educated around 1600s 1700s Studied the natural world to better understand God s Plan All species were divinely created perfectly all at the same time Around 6000 years ago based on Judeo Christian book of Genesis from the Old Testament Islam and Hindu religions also have similar creation story Side Note As early as 4th century Saint Augustine wrote God probably only created simple life forms and these developed over time Carolus Linnaeus 1750 Organized Life in a nested classification system based on similar appearance Each type of organism had a 2 part binomial scientific name Genus Species Either Italicized or Underlined Charles Darwin 1809 1882 Attended Cambridge to become a minister and a naturalist 1831 unpaid naturalist on 5 year voyage on the HMS Beagle 1 He observed that organisms on same continent more similar than ones on different continents 2 He saw a correlation between location and similarity and this suggested common ancestry Extended Malthus ideas to plants and animals Populations in nature are capable of far greater growth than natural resources can support Survival of the fittest Thomas Malthus 1766 1834 Demographer and political economist He said the fate is the poor is inescapable because their reproduction exceeds their means of sustenance e g higher infant mortality and childhood mortality This was the first suggestion of resource limitation competition leading to survival of the fittest Alfred Wallace 1858 Sends Darwin an example of his manuscript outlining his idea of evolution by natural selection which forces his hand in publishing his manuscript On the Origin of Species c catastrophism Georges Cuvier 1769 1832 One of the early Paleontologists also a natural theologian Accepted divine creation Believed in a relatively young age for Earth Sporadic catastrophes caused the appearance and disappearance of organisms the fossil record E g Local floods wiped out existing species and neighboring species moved in a k a No Evolution d uniformitarianism James Hutton 1726 1797 Geological gradualism Geological features were formed slowly and gradually over a long period of time not by catastrophes e g erosion and sedimentation Charles Lyell 1797 18 Mechanisms of geological change are constant over time The same processes that happen today happened in the past at the same rate Therefore The earth must be very old to accumulate all of the geological changes that have occurred Jean Baptiste Lamarck 1744 1829 Species evolve by gradually changing to adapting to their environment Evolutionary relationships among animals Right idea wrong mechanism Use and disuse if you use it it becomes stronger if you don t use it then you lose it over time Inheritance of acquired characteristics the traits that are acquired through lifetime by responding to the environment can be inherited 2 a What is the biological meaning of the term evolution Species change over time and new species arises by the modification of earlier species b Contrast microevolution with macroevolution Microevolution The gradual evolution of traits within a population of a species over time populations evolve not individuals Macroevolution The evolution of an entirely new species 3 Describe explain how each of the following served as evidence at the time of Darwin that evolution could be a means by which life s diversity arose a artificial selection b comparative anatomy c geology d paleontology e comparative embryology 4 a How can molecular biology provide evidence for evolution b Provide two examples 5 Distinguish between a homologous b analogous and c vestigial structures providing at least ONE EXAMPLE of each 6 a What did Darwin find intriguing about the finches on the Galapagos Islands There were 14 endemic species of finches found nowhere else b Explain why how the Galapagos finches might have helped Darwin formulate his hypothesis of evolution by natural selection They evolved from a common mainland ancestor each adapted to different lifestyles conditions on the various islands 7 a Describe the process by which populations evolve via natural selection 1 Within a population more offspring are produced that can survive Therefore there is a competition for resources struggle for existence 2 Random variation exists in all organisms and most is heritable genetic 3 Some of this variation affects fitness therefore the ability to survive and reproduce is random 4 More fit individuals produce more offspring and pass along more of their genes to the next generation 5 This results in a change in gene composition from one generation to the next with adaptive characteristics accumulating over time This change in a gene composition in a population over time is evolution b Why is it said that genetic variation is a prerequisite is required for evolution by natural selection There is differences in survival and reproduction among individuals favoring the advantageous rates 8 Lamarck thought that evolution was the best explanation for life s diversity as did Darwin How did Darwin s view differ from Lamarck s Lamarck had the right idea about evolution but he had the wrong mechanism which Darwin had Lamarck had two ideals about the mechanism of evolution that if you use a body part it becomes stronger if you don t then over time it disappears traits that an individual acquires in his lifetime by adapting to their environment can be passed along to their offspring Darwin s explanation is based on natural selection survival of the fittest based on Malthus ideals 9 Explain what is meant by the phrase populations evolve not individuals The individuals in a population that cannot adapt will slowly die off but the ones in that species that are able to survive will reproduce yielding a population
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