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Evolution A population changes over time. Charles Darwin (1809- 1882)

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Presentation on theme: "Evolution A population changes over time. Charles Darwin (1809- 1882)"— Presentation transcript:

1 Evolution A population changes over time

2 Charles Darwin ( )

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6 Lamarck- Inheritance of Acquired Characteristics

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8 Must be Genetic  You cannot “ force” yourself to have a characteristics  Ex. You cannot force yourself to be lactose tolerant  Bacteria CANNOT acquire resistance to antibiotics  New traits cannot be created during your lifetime  Only genes can be passed on

9 Lyell

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11 Fossils

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13 Darwin’s Finches  Biogeography- geographic distribution of life forms  Galapagos Islands- Volcanic islands off the coast of South America  Species were slightly different than the ones on the mainland  Finches- different beaks depending on the food available Cactus eating finch-more point beak  Insect eating finch- sharp ( trees)  Types of seeds All descended from one mainland Finch  DESCENT WITH MODIFICATION from a COMMON ANCESTOR

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24 Blue Footed Boobie

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28 Natural Selection  Mechanism for evolutionary change 1. Inherited variations:  Mutations- changes in DNA  Meiosis 2. Not all individuals survive 3. Adaptations( traits that help an organism be more suited to the environment ) increase survival and reproductive success ( Fitness - reproductive success) 4. Genes for adaptations increase in each generation

29 Artificial Selection

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31 The result of Natural Selection is a population adapted to the local environment

32 Types of Natural Selection

33 Evidence for Evolution 1. Fossils 2. Biogeographical 3. Anatomical 4. Biochemical 5. Embryology 6. Examples- Antibiotic

34 Fossils

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38 Biogeography

39 Anatomical Evidence a. Homologous Structure: Structures that are similar because they are inherited from a common ancestor

40 Anatomical Evidence b. Analogous Structures: features are similar in function but not in structure. They do not derive from a recent common ancestor but in response to a similar environment.

41 ANALOGOUS STRUCTURES

42 Anatomical Evidence  C. Vestigial structures: no longer have function. occur because organism inherit anatomy from their ancestors.  Ex. Some snakes have small hindlimbs  Humans: Appendix, wisdom teeth, tail bone

43 THEAPPENDIX VESTIGIAL STRUCTURE

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45 KOALA

46 EUCALYPTUS

47 Biochemical  Living organisms use DNA, and many identical enzymes (same 20 amino acids)  Degree of similarity of DNA sequence or amino acid structure based on how closely related

48 Embryology( Development)

49  Embryos of closely related organisms often have similar stages in development.

50 Causes of Microevolution 1. Mutations are the raw material for evolutionary change 2. Gene Flow- 3. Non random mating 4. Genetic Drift

51 Speciation ( Macroevolution)


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