BIOL 2500 Lecture Notes - Lecture 13: Stabilizing Selection, Frequency Distribution, Directional Selection

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 2500
• Professor: Roman Gietz

Document Summary

Polygenic and multifactorial traits are controlled by many genes and show continuous variation, with a range of values in an uninterrupted continuum. Human height is an example of a multifactorial trait with continuous variation. Adult height is in uenced by multiple genes. Phenotypes are in uenced by environmental factors, too, such as nutrition. Parents trait a genetic potential" to offspring that may or may not be met, depending on environment. Continuous variation of polygenic traits results from effects of multiple genes that may exert different amounts of in uence. Eye color is in uenced by other genes to a lesser degree, modi er genes. In some polygenic traits, the continuous distribution of phenotype results from incremental contributions by multiple genes. Additive genes, and each can be assigned a value that indicated its contribution to the polygenic trait, For certain traits each of the additive genes has an approximately equal effect.