ADAPTATION IS THE BASIS FOR BIODIVERSITY
Peter J. Park
THE MODEL SYSTEM: THE THREESPINE STICKLEBACK (Bell 1995)
Please watch Youtube video: http://youtu.be/dUQgj49dtWY
The founding of derived, freshwater populations:
• Migratory, breeding sea-run fish can get into lakes.
• If lake then becomes land-locked, then a derived freshwater population is borne,
founded by these sea-run fish.
• Along opposite ends of a continuum of lake types are shallow lakes and deep
lakes.
• In these lakes, anatomical changes in fish from derived freshwater populations
is driven by what they eat.
• Shallow lakes are dominated by large benthic invertebrates  benthic
stickleback
• Deep lakes do not have benthic invertebrates, making smaller plankton the
predominant food source  planktivorous stickleback
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ADAPTATION IS THE BASIS FOR BIODIVERSITY
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Peter J. Park
ADAPTATION IS THE BASIS FOR BIODIVERSITY
Peter J. Park
(Aguirre 2009)
Ecotype - describes a genetically distinct geographic variety or population within species
(or among closely related species), which is adapted to specific environmental conditions
- Benthic ecotype
- Planktivorous ecotype
Allopatric ecotypes – only one of the stickleback ecotypes is found in a lake
Sympatric ecotypes – both ecotypes are found in the same lake.
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ADAPTATION IS THE BASIS FOR BIODIVERSITY
Peter J. Park
Hybrids between sympatric benthics and planktivores have poor survival (Gow et al.
2007).
----------------------------------------------------------------------------------------References
Aguirre, W.E. 2009. Microgeographical diversification of threespine stickleback: body
shape–habitat correlations in a small, ecologically diverse Alaskan drainage.
Biological Journal of the Linnean Society 98: 139–151.
Bell, M.A. 1995. Intraspecific systematics of Gasterosteus aculeatus populations:
implications for behavioral ecology. Behaviour 132: 1131-1152.
Coyne, J.A. & H.A. Orr. 2004. Speciation. Sinauer Associates, Inc.
Gow JL, C.L. Peichel, & E.B. Taylor. 2007. Ecological selection against hybrids in
natural populations of sympatric threespine sticklebacks. Journal of Evolutionary
Biology 20: 2173-2180
Schluter, D. 2001. The Ecology of Adaptive Radiation. Oxford University Press.
Programs
Free shape analysis software (http://life.bio.sunysb.edu/morph/)
tpsUtil
tpsDIG2
tpsRelw
Free concept map software (http://cmap.ihmc.us/)
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