Читать книгу Infants and Children in Context - Tara L. Kuther - Страница 126

Everyone has a different genetic makeup and therefore responds to the environment in a unique way. In addition, any one genotype can be expressed in a variety of phenotypes. There is a range of reaction (see Figure 2.7), a wide range of potential expressions of a genetic trait, depending on environmental opportunities and constraints (Gottlieb, 2000, 2007). For example, consider height. Height is largely a function of genetics, yet an individual may show a range of sizes depending on environment and behavior. Suppose that a child is born to two very tall parents. She may have the genes to be tall, but unless she has adequate nutrition, she will not fulfill her genetic potential for height. In societies in which nutrition has improved dramatically over a generation, it is common for children to tower over their parents. The enhanced environmental opportunities (in this case, nutrition) enabled the children to fulfill their genetic potential for height. Therefore, a genotype sets boundaries on the range of possible phenotypes, but the phenotypes ultimately displayed vary in response to different environments (Manuck & McCaffery, 2014). In this way, genetics sets the range of development outcomes and the environment influences where, within the range, that person will fall.

Description

Figure 2.7 Range of Reaction

Source: Adapted from Gottlieb (2007).