24-3 Feature Investigation


Published on

Published in: Education
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

24-3 Feature Investigation

  1. 2. The Basics <ul><li>Cichlids, Pundamilia pundamilia vs. Pundamilia nyererei , and Courtship </li></ul>
  2. 3. Cichlids <ul><li>Fish from the Cichlidae family </li></ul><ul><li>Large diverse family </li></ul><ul><ul><li>Ex. Can be from 1 in to 3 ft long </li></ul></ul><ul><li>Between 1,300 and 3,000 species </li></ul><ul><ul><li>New species are discovered annually </li></ul></ul><ul><li>One of the largest vertebrate families </li></ul><ul><li>Found in Lake Malawi, Lake Victoria, and Lake Tanganyika with the most diversity </li></ul><ul><ul><li>More than 1,800 species found </li></ul></ul>
  3. 4. P. Pundamilia and P. nyererei <ul><li>Part of the Cichlid family </li></ul><ul><li>Belong to the same genus but are of different species </li></ul><ul><li>In certain locations the two species will not interbreed and act as two different biological species </li></ul><ul><li>In other locations the two species readily interbreed and produce fertile offspring </li></ul><ul><li>Interbreeding: mating between animals of different species that results in fertile offspring </li></ul><ul><li>Both live are in Lake Victoria </li></ul><ul><li>P. pundamilia </li></ul><ul><ul><li>Grayish on the top and sides </li></ul></ul><ul><ul><li>Dorsal fin is metallic blue and red </li></ul></ul><ul><li>P. nyererei </li></ul><ul><ul><li>Red-orange on the top </li></ul></ul><ul><ul><li>Yellow on the sides </li></ul></ul><ul><li>Both are black underneath and have black vertical stripes on their sides </li></ul><ul><li>An orange monochromatic light can hide their differences in color </li></ul>
  4. 5. <ul><li>P. pundamilia </li></ul><ul><li>P. nyererei </li></ul>
  5. 6. P. Pundamilia (top) and P. nyererei (bottom) under the orange monochromatic light
  6. 7. Courtship <ul><li>The male swims towards the female </li></ul><ul><li>The male shows the side of his body to the female (lateral display) </li></ul><ul><li>When interested, the female will swim towards the male and the male will quiver </li></ul>
  7. 8. The Experiment <ul><li>Introduction, Hypothesis, Materials, Procedure, Results, and Conclusion </li></ul>
  8. 9. Introduction <ul><li>The researchers were Ole Seehausen and Jacques van Alphen </li></ul><ul><li>Wanted to know the effects of male coloration in a female’s choice in a mate </li></ul>
  9. 10. Hypothesis <ul><li>Female African cichlids choose mates based on the coloration of males </li></ul>
  10. 11. Materials <ul><li>Four Pundamilia pundamilia male </li></ul><ul><li>Four Pundamilia nyererei male </li></ul><ul><li>Four Pundamilia pundamilia female </li></ul><ul><li>Four Pundamilia nyererei female </li></ul><ul><li>One fish tank </li></ul><ul><li>Two small glass enclosures </li></ul><ul><li>Orange monochromatic light </li></ul>
  11. 12. Procedure <ul><li>Put one female into the large tank and one male into each of the small enclosures within the large tank </li></ul><ul><ul><li>The Combinations </li></ul></ul><ul><ul><ul><li>P. pundamilia female with P. pundamilia male and P. nyererei male </li></ul></ul></ul><ul><ul><ul><li>P. nyererei female with P. pundamilia male and P. nyererei male </li></ul></ul></ul><ul><li>Observe which male the female is drawn to under normal light compared to orange monochromatic light </li></ul>
  12. 13. The experiment under normal light conditions
  13. 14. The experiment under the orange monochromatic light
  14. 15. Results <ul><li>Under normal light, females preferred males of their own species </li></ul><ul><ul><li>P. pundamilia females with P. pundamilia males </li></ul></ul><ul><ul><li>P. nyererei females with P. nyererei males </li></ul></ul><ul><li>Under orange monochromatic light, the preference that females exhibited under normal light disappeared </li></ul><ul><li>The results show diversifying selection </li></ul><ul><ul><li>A type of natural selection that is in favor of the survival of multiple genotypes that would create multiple phenotypes </li></ul></ul>
  15. 17. Conclusion <ul><li>Similar light conditions in their native habitats may be the reason why sometimes they interbreed and sometimes they do not </li></ul><ul><li>This type of sexual selection could divide a large population into smaller populations </li></ul><ul><li>The separate populations could eventually become distinct species </li></ul>