1 / 10

15.3 – Examples of Evolution

15.3 – Examples of Evolution. Factors in Natural Selection. 1. All populations have genetic variation. All individuals have a slightly different genetic makeup . 2. The environment presents challenges to successful reproduction. Unsuccessful individuals do not pass on genes.

thalia
Download Presentation

15.3 – Examples of Evolution

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. 15.3 – Examples of Evolution

  2. Factors in Natural Selection 1. All populations have genetic variation. • All individuals have a slightly different genetic makeup . 2. The environment presents challenges to successful reproduction. • Unsuccessful individuals do not pass on genes.

  3. Factors in Natural Selection 3. Individuals usually produce more offspring than the environment can support. • Creates competition. 4. Better suited individuals produce more successful offspring. • Successful genes take over population.

  4. Evolution in Action: Anole Lizards • Scientists studied Anole lizards of the Caribbean islands: • Cuba, Hispaniola, Jamaica and Puerto Rico. • Each species’ body type correlates to its specific habitat needs: • Trunk/ground dwellers= Stalky bodies; longer legs. • Twig dwellers= Slender bodies; short legs and tails. • Grass dwellers= Slender bodies; long tails.

  5. Evolution in Action: Anole Lizards • Scientists found: • Distinct species with the same body type on different islands. • Hypothesized that each twig-dwelling anole evolved independently on each island from one distant ancestor. • CONVERGENT EVOLUTION: When unrelated species become more similar as they adapt to the same kind of environment.

  6. Evolution in Action: Darwin’s Finches • Darwin collected 16 species of finches • All had different beaks. • All of them evolved from a single ancestor. • Adapted to different food sources. • DIGERGENT EVOLUTION/ADAPTIVE RADIATION: Two or more related but distinct populations become more and more dissimilar as they fit different parts of the environment.

  7. Evolution in Action: Dogs • Today’s domesticated dogs are all descendants of the wolf. • 10,000 years • Originated when relatively tame wolves coexisting with humans were bred, producing increasingly tame wolf ancestors. • Some natural traits are lost in the process.

  8. Evolution in Action: Dogs • Today’s breeds were selected for distinct traits. • Herding Dogs: Eye and Stalk, don’t kill. • Hounds: Chase. • Retrievers: Grab prey, don’t eat. Etc…. • Artificial Selection: The selective breeding of organisms by humans for specific desirable traits.

  9. Evolution in Action: Dogs

  10. Evolution in Action: Flowers and their Pollinators • Coevolution: The evolution of two or more species that is due to mutual influence, often in a way that is beneficial. • Shape of plants and flowers fit the specific characteristics of their pollinators.

More Related