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Directional selection Notes: Definitions & Explanations PDF | Download eBooks

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Study Directional selection lecture notes PDF with biology definitions and explanation to study What is Directional selection?. Study directional selection explanation with biology terms to review biology course for online degree programs.

Directional selection Definition:

  • Directional selection occurs when conditions favor individuals exhibiting one extreme of a phenotypic range, thereby shifting a population's frequency curve for the phenotypic character in one direction or the other.

    Campbell Biology by J.B. Reece, L.A. Urry, M.L. Cain, S.A. Wasserman, P.V. Minorsky, R.B. Jackson



Directional selection Notes:

Directional selection is common when a population's environment changes or when members of a population migrate to a new (and different) habitat. For instance, an increase in the relative abundance of large seeds over small seeds can lead to an increase in beak depth in a population of Galapagos finches. SO in this way external environmental factors may contribute towards the selection of a phenotype.

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