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Adaptation,Variation and Natural Selection

Adaptation,Variation and Natural Selection. March 27TH. Adaptations and Survival. An adaptation is a structure , behavior or physiological process These help an organism to survive and reproduce in particular environment Example: camouflage/mimicry

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Adaptation,Variation and Natural Selection

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  1. Adaptation,Variation and Natural Selection March 27TH

  2. Adaptations and Survival • An adaptation is a structure, behavior or physiological process • These help an organism to survive and reproduce in particular environment • Example: camouflage/mimicry • Can you find the “hidden organisms” in the following slide?

  3. Mimicry (mimic environment)/Camouflage

  4. Other Adaptations • Biochemical and Body Processes • Hibernation in ground squirrel • Structural Adaptation • Sharp talons and excellent vision of owl • Thick leaves of buffalo berry that help to reduce the water loss on hot summer days

  5. Adaptation • Different kinds of teeth for different animals, say carnivore ripping teeth and herbivore grinding teeth • Different tissues within species • Heart vs. eye etc.

  6. How do These Adaptations Develop? • They are a result of a gradual change of characteristics over time • A variation that helps an individual in a population is likely to be passed on from survivor to survivor • Some variations help and some do not, not all variations become adaptations!

  7. Variation Within a Species

  8. Let’s Look at Our Variations! • Question: Are there measureable differences in sizes among individuals of a species? • Two students from each table, measure your thumb and your middle finger • Collect the data and graph this information • Draw a data table and a bar graph that best suits the data gathered • Conclude what you see with this data

  9. Biological Species • A group of reproductively compatible populations • How does variation within a species occur?

  10. Genetics • Organisms that reproduce sexually have a blueprint from both parents • Through this reproduction, particular traits are passed on to the new organisms

  11. Mutations • Mutations are genetic changes that happen in DNA • Occur from mistakes that happen when DNA is being copied

  12. Natural Selection: It is the production of variations due to: Mutations: Changes in the DNA Random mate selection & fertilization Do we see variation within different wild species ?

  13. Natural Selection • Individuals with favorabletraits are more likely to leave more offspring better suited for their environment. • Example: English peppered moth (Biston betularia) - light and dark phases

  14. Humans select traits for dogs, pigeons and other animals when they breed them (we call this ARTIFICIAL SELECTION). Bred dogs came from a single original species

  15. NOBODY!! There is no agent involved in natural selection. Natural selection is a process of elimination INDIVIDUALS THAT HAVE TRAITS THAT ARE BEST ADAPTED FOR THE CURRENT ENVIRONMENT ARE THE ONES THAT SURVIVE TO BREED AND PASS ON THEIR GENES TO THE NEXT GENERATION. Organisms not possessing the beneficial traits either die or don’t have as many offspring. Natural Selection is Survival of the fittest

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