1 / 8

What is evolution ?

What is evolution ?. Change through time. Biological evolution Change in allele frequencies in populations. How evolution works:. Basic biological facts. 1) mutations introduce genetic variation. 2) some individuals survive and reproduce. 3) their genes get passed on.

miron
Download Presentation

What is 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. What is evolution? Change through time Biological evolution Change in allele frequencies in populations

  2. How evolution works: Basic biological facts 1) mutations introduce genetic variation 2) some individuals survive and reproduce 3) their genes get passed on IF only some of the indv’s in the pop’n survive & reproduce and IF the indv’s that survive & reproduce are NOT representative of the starting pop’n THEN the 2 generations will differ Voila!! Genetic change in the population… evolution!

  3. deleterious mutations X X survival & reproduction X high mutation rate survival & reproduction variation in HIV population X X X survival & reproduction X X some change in population more change in population population of HIV particles

  4. Basic biological facts 1) mutations introduce genetic variation 2) some individuals survive and reproduce 3) their genes get passed on IF only some of the indv’s in the pop’n survive & reproduce and IF the indv’s that survive & reproduce are NOT representative of the starting pop’n THEN the 2 generations will differ How evolution works: DIFFERENCE in % of POP‘N with different genes

  5. Basic biological facts 1) mutations introduce genetic variation 2) some individuals survive and reproduce 3) their genes get passed on WHY NOT?? IF only some of the indv’s in the pop’n survive & reproduce and IF the indv’s that survive & reproduce are NOT representative of the starting pop’n THEN the 2 generations will differ How evolution works: DIFFERENCE in % of POP‘N with different genes

  6. reproduction AZT AZT X X most mutations are deleterious reproduction AZT AZT reproduction resistant HIV particles  survive AZT  reproduce & pass on their genes

  7. Natural selection: 1) genetic variation * 2) some genes improve survival or reproduction 3) these genes get passed on INCREASE in % of POP‘N with beneficial genotype Whether a genotype is beneficial DEPENDS ON THE ENVIRONMENT Population becomes adapted to the environment because of change in gene frequency

  8. Evolution is important to our lives • Food • artificial selection for better crops & livestock • pesticide resistance • Health • drug resistance • emerging diseases • Environment • invasive species • endangered species

More Related