1 / 10

5 causes of Micro evolution (Animated activity-Campbell 23A)

EVOLUTION. micro. 5 causes of Micro evolution (Animated activity-Campbell 23A). Micro evolution. 1. Mutations. Random changes in DNA that create a new allele. Occurs in 1 / 1,000,000 gametes. * the only way to get new genes*. Micro evolution. 2. Genetic drift.

ferrol
Download Presentation

5 causes of Micro evolution (Animated activity-Campbell 23A)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EVOLUTION micro 5 causes of Microevolution (Animated activity-Campbell 23A)

  2. Microevolution 1. Mutations • Random changes in DNA that create a new allele. • Occurs in 1 / 1,000,000 gametes. • * the only way to get new genes*

  3. Microevolution 2. Genetic drift • Random changes in the freq of alleles in a population. • 2 causes:

  4. Microevolution 2. Causes of genetic drift- • A. Bottleneck effect -random events the drastically reduce pop. sizes. Earthquakes, floods, etc. • Ex: Northern Elephant seals; 2030,000 • For 24 genes- no genetic variation at all

  5. Microevolution 2. Causes of geneticdrift- • B. Founder Effect • the colonization of a new location by a small # of individuals. * founding population does not represent parent population • Examples: • Amish- high incidence of polydactilism • Darwin’s finches

  6. Microevolution 3. Gene flow • Migration in or out of a population. • Increases or decreases freq of certain alleles. • Reduces genetic differences between neighboring populations.

  7. Microevolution 4. Non-random mating • The selection of mates other than by chance. • Every male has an equal chance of mating with every female.

  8. Microevolution 5. Natural selection • Organisms have variations • Environment has limited resources • Some variations are advantageous in the environment. • “Survival of the fittest”- those best adapted to the environment survive & reproduce.

  9. Natural Selection • Finches on Galapagos Islands • variation in beaks • each type was “successful” in it’s own niche • Darwin used the term “fitness” to describe a bird that survived and reproduced.

  10. Microevolution 5. Natural selection- 3 types

More Related