Question

What accounts for phenotypic variation in a quantitative character? (Remember genetic variance plays a role too).

Answer 1

Mendelian character are classified as distinct phenotypic categories. In contrast to this,the variability exhibited by many traits fail to fit into separate phenotypic classes ( discontinuous variability) but form a spectrum of phenotype that blend imperceptibly from one type to another ( continuous variability). Quantitative traits are governed by many genes at different loci and each contribute such a small amount to the phenotype that their individual effects cannot be detected by Mendelian methods.The contribution of genetic or environmental effects vary, depending on the trait ,but in most cases , neither factor governs the variation exclusively.