For the traits listed in the previous problem, which do you think are likely to be multifactorial traits, with phenotypes that are influenced by genes and environment? Identify two environmental factors that might play a role in phenotypic variation of the traits you identified.

Key Concepts

Multifactorial Traits

Multifactorial traits are characteristics influenced by multiple genes and environmental factors. Unlike single-gene traits, which follow Mendelian inheritance patterns, multifactorial traits exhibit a range of phenotypes due to the complex interplay between genetic predispositions and environmental influences. Examples include height, skin color, and susceptibility to diseases.

Phenotypic Variation

Phenotypic variation refers to the observable differences in traits among individuals within a population, resulting from both genetic and environmental factors. This variation is crucial for natural selection and evolution, as it provides the raw material for adaptation. Understanding the sources of phenotypic variation helps in identifying how traits can change over generations.

Environmental Factors

Environmental factors are external influences that can affect the expression of genes and, consequently, phenotypes. These factors can include nutrition, climate, exposure to toxins, and lifestyle choices. For example, a person's height can be influenced by both genetic factors and nutritional availability during their growth period, illustrating the interaction between genes and environment.