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1. What are the 3 requirements for Natural Selection to occur

1. con't. Variation in genes. . 2. Variation in genes Sources of Variation for Adaptation

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1. What are the 3 requirements for Natural Selection to occur

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    1. 1. What are the 3 requirements for Natural Selection to occur? 1. Variation in traits Eye color, hair Body size, shape Ability to run, see more clearly or hear better

    3. 1. Con’t variation in reproduction. 3. Variation in reproductive capacity - theory -             *most fit survive better and have more offspring,             *next generation has individuals better adapted

    4. 2. What is adaptation, how does it work and give some examples. Adaptation:     -adjustment to environmental  conditions: as in  modification of an organism or     its parts that makes  it more fit for existence under the conditions of its  environment.

    5. 2. Con’t 2 types of adaptations: Examples: physiological: Lynx; Walking twig behavioral:  Galapagos Gull

    6. 3.  Darwin’s Theory of Natural Selection  Origin of the Species – book written for both scientists and non-scientists. Created biggest debate of science vs religion ever…  Survival of the Fittest – theory that only the strongest survive to reproduce and therefore are better adapted to the environment. Basis for theory of evolution.

    7. 4. Darwin’s finches – helped define theory.  Each bird species evolved from a common finch from the mainland (C. America). All have different beaks depending on feeding behavior

    8. 4. Con’t Galapagos (Darwin’s) Finches

    9. 5. Grant’s study of Galapagos Finches   Peter and Rosemary Grant, Harvard Scientists Introduction: Investigated interbreeding and effects of weather on Galapagos finches.   Weighed and measured 19,000 birds from 24 generations –    * All from 1 island (Daphne Major) *3 species Geospiza         a. G. magnirostris         b. G. fortis         c. G. fuliginosa

    10. 5. Con’t grant study – type of finches Geospiza magnirostris – largest finch, large seeds G. fortis – medium, mixed seeds G. fuliginosa – smallest bird, smallest seeds

    11. 5. Con’t Grant Galapagos finch study   Methods: *Banded 300 –1000 birds per year      *Recorded mates, offspring and survival * maintained study for 10 years.      *Compared to types of food source      *Abundance      *size and hardness of seed      *temperature and rainfall

    12. 5. Con’t Grant Study -Results 1977 drought  all birds decreased 1300 to 300  G. magnirostris  88 to 119  G. fortis 1200 to 180 * larger birds survived  G. fuliginosa     12 to 1

    13. Beak shape changed w/ variation in moisture and seed availability. During dry years only large seeds available.

    14. 6. Genetic Terms     * Gene         The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein.     *Allele         Variant forms of the same gene. Different alleles produce variations in inherited characteristics such as eye color or blood type.     *Chromosome         Structure found in the nucleus of a cell, which contains the genes. Chromosomes come in pairs. Normal human cells have 46 chromosomes.

    15. 6. Con’t genetic terms *Genotype         The genetic constitution of an organism or cell;     *Phenotype         The observable physical and/or biochemical characteristics of the expression of a gene;              the clinical presentation of an individual with a particular genotype

    16. 7. What is a hybrid? Why important?   -an offspring of two animals or plants of different races, breeds, varieties, species, or genera.         a.  Example:  Mule is a cross between a horse and a donkey                 usually sterile has characteristics of each

    17. 8. What is Genetic Isolation? Why important? Can lead to formation of new species – 2 types         a.  Geographical:   barriers to breeding between species ocean, mountains, review unit 1         b.  Reproductive:    species specific mechanisms (song, behavior, visual cues, pheromones)

    18. 9. Support for Darwin’s theory  South American Fossils - Giant sloths and armadillo         Rodent discovered last week (giant guinea pig creature) from same area  Clearly not explained by Uniformitarianism         -a geological doctrine that existing processes acting in the same manner as at present are sufficient to account for all geological changes

    19. 10.  Human adaptation to the Environment     a.  skin color:  darker near the equator; light nearer artic climates due to vitamin D absorption     b.  malaria and sickle cell anemia gene -africans current Malaria info- current world distribution     c.  milk intolerance - asians

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