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Evidence of evolution

Evidence of evolution

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Evidence of evolution

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  1. Evidence of evolution By Martin Samaj

  2. Evolution • the word evolution has several meanings all of which involve gradual development of things • definition: Evolution is the cumulative change in the heritable characteristics of a population • change in genetic material of a population of organisms through successive generations • although the changes from generation to generation is relatively small in long term these changes can result in an emergence of new species • similarities among species suggest that all known species descend from a common ancestor

  3. The Fossil Record - Palaeontology • Existence of fossils is difficult to explain without evolution • For example look at Acanthostega • Backbone as vertebrates and 4 limbs • Shows that land vertebrates could have evolved from fish via an aquatic animal with legs

  4. Homologous, anatomical structures • There are some similarities between organisms in their structure • ex. bones in the limbs of vertebrates are very similar although used in different ways • The structure is called pentadactyl limb • These structural similarities are most likely due to evolution from a common ancestor - homologous structures

  5. Selective Breeding of Domesticated Animals • the breeds of animal that are reared for human use are clearly related to wild species • these can inbreed with the wild species • the drastic differences between the wild and domesticated animals is evidence that species can evolve rapidly

  6. Lenski’s long term experiment • Richard Lenski started a long term evolution experiment • It involves the bacterium E.coli • It continues to this day and since it started 40 000 generations have already passed

  7. William Dallinger • He conducted an experiment that lasted 7 years and involved incubation of bacteria at various temperature • He slowly increased the temperature from 60F to 158F • The growing cultures shown distress at 73F and would not certainly survive at 158F • However the organisms at the end were fine at 158F, but couldn’t grow at 60F

  8. The End