Download
natural selection n.
Skip this Video
Loading SlideShow in 5 Seconds..
NATURAL SELECTION PowerPoint Presentation
Download Presentation
NATURAL SELECTION

NATURAL SELECTION

163 Vues Download Presentation
Télécharger la présentation

NATURAL SELECTION

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. NATURAL SELECTION The scientifically identified method explaining how evolution happens.

  2. My Students Are Comedians

  3. Types of Selection Processes What is a population? What would be some pressures that could develop upon a population? With such pressures what could happen to a population? What is Artificial Selection? Natural Selection is based upon natural pressures to a population.

  4. Stabilizing Selection

  5. Disruptive Selection

  6. Directional Selection

  7. Frequency-Dependent Selection In positive frequency-dependent selection, the fitness of a phenotype increases as it becomes more common. In negative frequency-dependent selection, the fitness of a phenotype increases as it becomes rarer. This is an example of balancing selection.

  8. Example Natural selection may favor non-poisonous butterflies that have the same color pattern as poisonous butterflies. This system is called Batesian mimicry.

  9. Sexual Selection By making themselves attractive to the opposite sex (intersexual selection, between the sexes). By intimidating, deterring or defeating same-sex rivals (intrasexual selection, within a given sex).