2.22 : 基因-环境相互作用

Gene expression is influenced by environmental factors such as radiation, temperature, behavior, nutrition, and stress.

The range of reaction suggests that genes set potential limits for physical traits, while environmental conditions shape the actual outcomes within those limits. For example, genetics might set a potential height range, such as 5'5" to 6'1", for an individual. However, environmental factors like nutrition and healthcare determine the actual height achieved within this range.

The genetic-environmental correlation highlights the bidirectional influence between genes and the environment, where each influences and responds to the other. For example, a child with a genetic predisposition to read may show an early interest in books, prompting parents and teachers to provide more books and support.

In epigenetics, researchers explore how identical genotypes can lead to diverse phenotypes. Identical twins, for instance, have the same genes but can exhibit significant differences in behaviors and mental processes, like musical proficiency or reading habits, based on the environment and life experiences.