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TOPIC : Evolution AIM : Explain the today ’ s theory of evolution.

Explore the theory of evolution, including natural selection, adaptation, speciation, and evidence for evolution. Discuss gradualism and punctuated equilibrium with examples and human impact on extinction.

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TOPIC : Evolution AIM : Explain the today ’ s theory of evolution.

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  1. TOPIC: Evolution AIM: Explain the today’s theory of evolution. Do Now: 1. Copy the topic and aim. 2. Complete # 6 on the back of your Natural Selection reading notes HW: “How did Mammoths Go Extinct” article (This will be collected and graded.)

  2. 6. There are 2 types of worms: worms that eat at night (nocturnal) and worms that eat during the day (diurnal). Birds eat during the day and seem to be eating only the diurnal worms while the nocturnal worms are in their burrows. Each spring when the worms reproduce, that have about 500 babies but only 100 of these ever become old enough become old enough to reproduce. • Favorable adaptation: • Unfavorable adaptation: • If speciation were to occur, which adaptation would the species have? Eating at night (not caught by birds) Eating during the day Nocturnal worms

  3. Identify the type of rock fossils are located in. • 2. Identify the layer with the oldest fossils. • 3. Identify the layer with the most complex fossils. • 4. Identify the layer with the youngest fossils. • 5. Identify the layer with the least complex fossils. A B Sedimentary rock F C D A A E F F

  4. What kind of evidence for evolution does this represent? Similarities in embryological development 2. What does this evidence suggest? These species evolved from a common ancestor.

  5. Identify the part of the theory of Natural Selection represented in the diagram below. Support your answer. • Speciation • One species of finch evolved into many species of finches.

  6. What environmental factor caused the speciation of finches? • The source of food on each island.

  7. Review: • Explain the theory of Natural Selection. • Explain what Darwin meant by the term overproduction. • Explain what organisms compete for and what the result of competition is. • Explain what Darwin says about variation. • Describe ‘Survival of the Fittest.’ • Describe speciation.

  8. Sources of genetic variation in a species Sexual Reproduction Genetic engineering Selective breeding Mutations (changes in DNA)

  9. Migration: moving into or out of an area

  10. Rate of Evolution

  11. 1. Gradualism:

  12. Evolution occurs SLOWLY & CONTINUOUSLYthrough time

  13. 2. Punctuated Equilibrium

  14. Sudden changes in a species after long period of no change

  15. http://www.youtube.com/watch?v=zjR6L38yReE

  16. Ex: Bacteria have evolved resistant to certain antibiotic

  17. Punctuated Equilibrium Today • Penicillin has been in use since 1943. It originally came from the fungus Penicillium. • 1947: Species of bacteria that cause pneumonia and other infections already had developed resistance to the drug. • By the 1990s, several disease-producing bacteria had become resistant to penicillin and many other antibiotics.

  18. When penicillin was used to kill bacteria, those with the penicillin-resistant variation survived, reproduced, and passed this trait to their offspring. • Over a period of time, this bacteria population became penicillin-resistant.

  19. PUNCTUATED EQUILIBRIUM GRADUALISM

  20. *BOTH THEORIES SEEMED TO HAVE OCCURRED DURING EARTH’S HISTORY*

  21. Which organisms have evolved quickly? • Those that reproduce at a very fast rate • Ex: bacteria, insects

  22. Extinction As long as species have been evolving, species have been going extinct. It is estimated that over 99.9% of all species that ever lived are extinct. The average life-span of most species is 10 million years, although this varies widely between taxa. There are a variety of causes that can contribute directly or indirectly to the extinction of a species or group of species. Most simply, any species that cannot survive or reproduce in its environment and cannot move to a new environment where it can do so, dies out and becomes extinct. Extinction of a species may come suddenly when an otherwise healthy species is wiped out completely, as when toxic pollution renders its entire habitat unlivable; or may occur gradually over thousands or millions of years, such as when a species gradually loses out in competition for food to better adapted competitors.

  23. In the natural course of events, species become extinct for a number of reasons, including but not limited to: • extinction of a necessary host, prey or pollinator • inter-species competition • inability to deal with evolving diseases • Sudden changing environmental conditions Recently, HUMANS have become an additional cause of extinction for some species, by being a mega-predator or by transporting animals and plants from one part of the world to another. (e.g., livestock released by sailors onto islands as a source of future food, rats escaping from boats). In most cases, introducing these invasive alien species, can affect native species directly by eating them, competing with them, and introducing pathogens or parasites that sicken or kill them or, indirectly, by destroying or degrading their habitat.

  24. What can cause extinction? • Very little variation in a species • Major environmental change • If adaptation no longer favorable  all organisms die  extinction

  25. Sexual repro, genetic engineering, selective breeding, mutations, migration Let’s summarize… 1. Identify some sources of variation. 2. Identify the theory in which there is no evolution for a long period of time followed by brief periods of change. Punctuated equilibrium 3. Identify TWO THINGS can cause a species to become extinct? • No variation within a species • Major environmental change the species cannot adapt to

  26. Which population of organisms would be in greatest danger of becomingextinct? • A population of organisms having few variations living in a unchanging environment. • A population of organisms having few variations living in an changing environment. • A population of organisms having many variations living in a unchanging environment. • A population of organisms having many variations living in an changing environment.

  27. Which statement could best be inferred from the information in this diagram? (1) Evolution does not involve gradual change.(2) Evolutionary changes can result in extinction.(3) Evolution begins with plants.(4) Evolution produces organisms that all fill the same niche.

  28. 1. Identify the common ancestor. Species A 2. Identify species that have become extinct. Species C, D, H, L, O, P 3. Identify the species that have not become extinct. Species J, K and M

  29. Which statement about the rates of evolution for different species is in agreement with the theory of evolution? (1) They are identical, since the species live on the same planet. (2) They are identical, since each species is at risk of becoming extinct. (3) They are different, since each species has different adaptations that function within a changing environment. (4) They are different, since each species has access to unlimited  resources within its environment.

  30. Which concept is not a part of the theory of evolution? (1) Present-day species developed from earlier species. (2) Some species die out when environmental changes occur. (3) Complex organisms develop from simple organisms over time. (4) Change occurs according to the needs of an individual organism to survive.

  31. Fossil records indicate that between 80 and 60 million years ago the structure of the horned dinosaur underwent rapid changes separated by long periods of stability. This pattern of change best illustrates the concept of • use and disuse (2) punctuated equilibrium (3) gradualism (4) enzyme specificity

  32. A key concept in the modern theory of evolution explains (1) how new organs arise according to the needs of an organism(2) how variations occur within a species(3) the continued increase in the human population(4) the presence of asexual reproduction within a species

  33. Some scientists suggest that the extinction of dinosaurs resulted from sudden global weather changes caused by the impact of an asteroid on Earth. This event most likely promoted the evolution of new species of animals. These ideas best support the concept of • punctuated equilibrium (2) use and disuse(3) gradualism(4) geographic isolation

  34. The diversity within the wild bird species in the diagram below can best be explained by which process? (1) natural selection   (3) ecological succession(2) asexual reproduction (4) mitotic cell division

  35. Which concept would be correctly placed in box X? • use and disuse     • variation            • transmission of acquired traits • changes in nucleic acids

  36. Which statement is not part of the concept of natural selection? • Individuals that possess the most favorable variations will have the best chance of reproducing. (2) Variation occurs among individuals in a population. (3) More individuals are produced than will survive. (4) Genes of an individual change to adapt to a changing environment

  37. According to the theory of natural selection, why are some individuals more likely than others to survive and reproduce? • Some individuals pass on to their offspring new characteristics they have acquired during their lifetimes. • Some individuals are better adapted to exist in their environment than others are. • Some individuals do not pass on to their offspring new characteristics they have acquired during their lifetimes. • Some individuals tend to produce fewer offspring than others in the same environment.

  38. Charles Darwin proposed that organisms produce many more offspring than can possible survive on the limited amount of resources available to them. According to Darwin, the offspring that are most likely to survive are those that  (1.) are born first and grow fastest  (2.) are largest and most aggressive  (3.) have no natural predators  (4.) are best adapted to the environment

  39. Darwin's studies of finches on the Galapagos Islands suggest that the finches' differences in beak structure were most directly due to  (1.) acquired characteristics in the parent finches  (2.) the size of the island where the finches live  (3.) mating behaviors of the different finch species  (4.) adaptations of the finches to different environments

  40. According to Charles Darwin, one factor that affects the evolution of a species is  (1.) variation due to genetic mutations  (2.) rapid fossil formation  (3.) survival of the fittest  (4.) exposure to environmental pollutants

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