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AIM. What is Evolution?. Evolutionary Theory. Process of change in species over a long time They are distinctly different from earlier forms. Proof of Evolution. Fossils provide clues to the history of earth’s organisms. Proof of Evolution. DNA Analysis (Gel Electrophoresis).

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  1. AIM What is Evolution?

  2. Evolutionary Theory • Process of change in species over a long time • They are distinctly different from earlier forms

  3. Proof of Evolution • Fossils provide clues to the history of earth’s organisms

  4. Proof of Evolution • DNA Analysis (Gel Electrophoresis)

  5. What did organisms evolve from? Multi-cellular Unicellular

  6. How do organisms acquire new traits so evolution can occur over many years? • Crossing-over during meiosis when gametes are formed • Mutations in gametes (Sperm or egg)

  7. Mutation in Gametes • Base pair sequence change • Change passed on to offspring

  8. Leads to Variety • Sexual Reproduction (Crossover during meiosis) • Mutations

  9. Variation in Dogs

  10. Variation in Ladybugs

  11. Variation in Frogs

  12. Variation in Finches

  13. Passed to Offspring • Mutations passed to offspring when they occur in gametes(sperm or egg)

  14. 1.Which phrase best defines evolution? 1.an adaptation of an organism to its environment 2.a sudden replacement of one community by another 3.a geographic or reproductive isolation of organisms 4.a process of change in organisms over a period of time

  15. 2.Which two factors provide the genetic basis for variation within a species? 1.asexual reproduction and geographic isolation 2.mutations and sexual reproduction 3.competition and protein synthesis 4.constant gene frequency and reproductive isolation

  16. 3.As a result of sexual reproduction, an organism can pass a gene mutation to its offspring if the mutation occurs in 1.a body cell 2.a gamete 3.liver tissue 4.white blood cells

  17. Aim What conditions are important to evolution?

  18. Force behind Evolution • The interaction between individual organisms and the environment

  19. Conditions Important to Evolution • Variation (Differences) • Overproduction • Finite supply of resources (limited) • Competition • Natural Selection

  20. Variation • New traits that can lead to evolution come from normal variation within species

  21. Overproduction • Population of a species remains stable • Turtle eggs

  22. Struggle for Survival • Finite Resources (not enough) • Competition among individuals of a species mean only the most adapted to the environment will survive

  23. Natural Selection • Evolution is controlled by nature not people • Organism that are best adapted to an environment will survive

  24. Selection by Environment • The proportion of individuals with advantageous traits will increase • This change over time is evolution

  25. Fitness • The member that is better fit will survive. • Fitness-The ability to survive

  26. Adaptation • An inherited characteristic that increases an organism’s chance for survival Quills

  27. Example-Adaptation • Long tongue lizard is better adapted than a lizard with a short tongue.

  28. Survival of the Fittest • Individuals that are better suited to their environment - survive and reproduce more successfully

  29. Natural Selection • Survival of the fittest is also referred to as Natural Selection • Environment changes first, those best adapted survive

  30. Adaptations • Beneficial traits will be passed on to offspring (More frequency) • Unfavorable traits will be less common

  31. Favorable Traits • Those best adapted pass on favorable adaptations to their offspring • Higher frequency of favorable traits are passed along to offspring increasing chances for survival of the species Camouflage

  32. Things to Remember • Individuals that produce the most offspring are the best adapted to the environment

  33. 1.In most populations, the individuals that produce the greatest number of offspring are 1.always the strongest 2.usually the best adapted 3.those that have only recessive traits 4.those that are the most intelligent

  34. 2.According to modern evolutionary theory, genes responsible for new traits that help a species survive in a particular environment will usually 1.not change in frequency 2.decrease gradually in frequency 3.decrease rapidly in frequency 4.increase in frequency

  35. 3.Even though the environment changes, a population that occupies a given geographic area will most likely continue to be found in this area if the 1.variations in the population decrease over time 2.members of the population decrease in number 3.members of the population exceed the carrying capacity 4.population passes on those genes that result in favorable adaptations

  36. 4. The kit fox and red fox species are closely related. The kit fox lives in the desert, while the red foxinhabits forests.Ear size and fur color are two differences that can be observed between the species.An illustration of these two species is shown below.  Which statement best explains how the differences between these two species came about? • Different adaptations developed because the kit fox preferred hotter environments than the redfox. • As the foxes adapted to different environments, differences in appearance evolved. • The foxes evolved differently to prevent overpopulation of the forest habitat. • The foxes evolved differently because their ancestors were trying to avoid competition.

  37. Aim What affects the rate of evolution among organism?

  38. Affects Rate of Evolution • Environmental Change - More Environmental change equals more Evolution - Less Environmental change equals less Evolution Horseshoe crab

  39. Affects Rate of Evolution • Offspring Produced - The more you produce the quicker organism evolves over time

  40. Affects Rate of Evolution • Time of Lifespan Lifespan for bacteria and insects are short so they evolve quicker compared to humans • More life cycles

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