1 / 49

Evolutionary Ecology

Evolutionary Ecology. Evidence of local adaptation. Environmental or Genetic Variation in WesternYarrow?. Creeping Bent Grass - Agrostis stolonifera. Adaptation in Trinidad Guppies Poecilia reticulata. Male and Female. Two males. Adaptation and natural selection in guppy populations.

floyd
Télécharger la présentation

Evolutionary Ecology

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. Evolutionary Ecology

  2. Evidence of local adaptation

  3. Environmental or Genetic Variation in WesternYarrow?

  4. Creeping Bent Grass - Agrostis stolonifera

  5. Adaptation in Trinidad GuppiesPoecilia reticulata Male and Female Two males

  6. Adaptation and natural selection in guppy populations John Endler

  7. Cline – Bergmann’s Rule

  8. Bergmann’s Rule in BearsSun bear, Spectacled bear, Brown bear, Polar bear

  9. Fig. 3. Mean ± SE body size (top) and egg to adult development time (bottom) as a function of latitude for lab-reared families of yellow dung fly males and females from six different latitudinal populations in Europe, at 15°C in the sequential experiment (CH: Switzerland; GB: England; D: Germany; S: Sweden; ISL: Iceland). Blanckenhorn W U , and Demont M Integr. Comp. Biol. 2004;44:413-424 The Society for Integrative and Comparative Biology

  10. Cline – Allen’s Rule Arctic Cool Temperate Warm Temperate Desert

  11. White clover – Trifolium repens

  12. Cline in cyanide production by white clover – dark circle populations with cyanide; white circle lack cyanide

  13. Clinal variation in gulls Herring Gull Lesser Black-backed Gull

  14. What is a species?

  15. Morphological species concept: • Assemblages of individuals with morphological features in common and separable from other such assemblages by correlated morphological discontinuities in a number of features. from Davis and Heywood

  16. Rubus - Blackberries

  17. Biological Species Concept Comte de Buffon Ernst Mayr

  18. Biological species concept A species consists of a groups of organisms which can sexually interbreed or at least have the potential to sexually interbreed (if geographically isolated) that are reproductively isolated from other such groups. This is based on two criteria: 1. do populations from the same locality normally interbreed? 2. if cross-fertilization does occur, are the hybrids viable and fertile?

  19. Sibling species Species which look almost identical morphologically but which do not interbreed. Drosophila pseudoobscura

  20. Gilia tricolor Gilia angelensis

  21. Polytypic species • Species made up of populations which differ morphologically but which will interbreed in nature.

  22. Variation in Song Sparrows

  23. Potential problems with biological species concept • Fossil species cannot be tested for reproductive isolation • Asexual species also cannot be test for reproductive isolation – each clone is genetically separate from all others – Mayr calls asexual species ‘paraspecies’

  24. Phylogenetic species concept • Species are defined based upon branching patterns in phylogenetic trees. Species are also defined based upon differences in evolutionary history. Species typically diverge when reproductively and/or geographically isolated.

  25. Western and Florida Scrub Jay

  26. Speciation • Speciation is the formation of new species. • Allopatric speciation - formation of new species occurs when populations of a species become geographically separated from each other and diverge so that when they co-occur they cannot interbreed. • Sympatric speciation - occurs when reproductive isolation occurs within the range of a population before any differentiation of the two species can be detected.

  27. Allopatric Speciation – Galapagos Islands Finches

  28. Darwin’s Finches

  29. Sympatric and Allopatric Speciation – Picture Winged Drosophila

  30. Eight Species of Picture- Winged Drosophila

  31. Founder Events with Picture Winged Drosophila

  32. Sympatric Speciation in Cichlids

  33. Variation in Lake Malawi and Lake Tanganyika Cichlids

  34. Polyploidy in Spartina cordgrasses • Polyploidy - an increase in the number of chromosomes beyond the typical diploid number - may be a doubling or greater - this happens most often in plants • Polyploidy often occurs following the production of hybrids

  35. Spartina alternifloramarsh – North Carolina

  36. Spartina alterniflora

  37. Spartina maritima

  38. Spartina x townsendii

  39. Spartina anglica

  40. Spartina anglica– invasive in New Zealand

More Related