Finchstudentpresentation

469 views
389 views

Published on

Published in: Travel, Education
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
469
On SlideShare
0
From Embeds
0
Number of Embeds
10
Actions
Shares
0
Downloads
4
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Finchstudentpresentation

  1. 1. Does Natural Selection act on Phenotypes or Genotypes? http://fig.cox.miami.edu/cmallery/150/unity/c1x17b-finches.jpg
  2. 2. The Grant Finch Study <ul><li>Peter and Rosemary Grant have studied and documented evolution of finch beaks on the Galapagos Islands. </li></ul><ul><li>Changes in habitat and seed availability on the environmentally turbulent islands favored some finches and not others. Successive generations of the birds showed different beak shapes. </li></ul>Columbiajournalist.org.science_reporting/2005/article.asp?...lid=606
  3. 3. Individuals within a population vary in their traits: Fig Figure 1: Histogram of distribution of beak depth of medium ground finches on Daphne Major, before and after the drought of 1977 (Grant 1986). Reprinted by permission of Princeton University Press. http://fig.cox.miami.edu/cmallery/iso/unity/case_study.htm
  4. 4. <ul><li>Some variable traits are heritable; they are passed on to offspring: </li></ul>http://scied.fullerton.edu/biol409/session4/elaborate_b.html
  5. 5. <ul><li>More offspring are produced than can survive because of limited resources such as food and nesting sites: </li></ul>Figures 3a and 3b: Figure 3a shows the population of Geospiza fortis before and after the drought in 1977. Figure 3b demonstrates seed abundance on Daphne major before and after the drought. http://scied.fullerton.edu/biol409/session4/elaborate_b.html
  6. 6. Individuals with advantageous traits will survive and reproduce: Figure 1: Histogram of distribution of beak depth of medium ground finches on Daphne Major, before and after the drought of 1977 (Grant 1986). Reprinted by permission of Princeton University Press. http://fig.cox.miami.edu/cmallery/iso/unity/case_study.htm
  7. 7. Review Time! <ul><li>Natural selection acts on phenotypes rather than genotypes of an organism: it’s actions change the allele frequencies in a population. </li></ul><ul><li>Variation within a species increases the likelihood that at least some members of a species will survive under changed environmental conditions. </li></ul>
  8. 8. <ul><li>The entire individual is the target of natural selection: </li></ul><ul><li>The of the individual is NOT the target of selection </li></ul>Columbiajournalist.org.science_reporting/2005/article.asp?...lid=606
  9. 9. Which Figure or Figures Would Support These Statements? <ul><li>Individuals within a population vary in their traits </li></ul><ul><li>Diversity of species increases the chance that at least some organisms of that species survive major changes in the environment </li></ul>
  10. 10. Internet Websites and Image Resources <ul><li>Columbiajournalist.org.science_reporting/2005/article.asp?...lid=606 </li></ul><ul><li>http://fig.cox.miami.edu/cmallery/iso/unity/case_study.htm </li></ul><ul><li>http://fig.cox.miami.edu/cmallery/150/unity/c1x17b-finches.jpg </li></ul><ul><li>http://scied.fullerton.edu/biol409/session4/elaborate_b.html </li></ul>

×