The phenotypic frequencies of a character sometimes form a smooth, bell-shaped curve because
A) only two distinct alleles underlie the trait.
B) environmental variation smooths out the gaps between phenotypes.
C) sampling error when measuring the trait smooths out the variation.
D) continuous, smooth variation has a very high mutation rate.

Question

Quizplus · Accepted Answer

Environmental variation can contribute to the continuous variation observed in phenotypic traits, leading to a smooth, bell-shaped curve in their distribution. This occurs because the environment can influence the expression of genes in various ways, resulting in a range of phenotypes even among individuals with similar genotypes.

The Phenotypic Frequencies of a Character Sometimes Form a Smooth