Читать книгу Child Development From Infancy to Adolescence - Laura E. Levine - Страница 178

Disorders such as sickle-cell disease and Tay-Sachs disease are created by a single recessive gene pair. However, most human behaviors are unlikely to be the result of only one gene. Polygenic inheritance means many different genes may interact to promote any particular trait or behavior. In addition, they may interact with environmental experiences in ways we describe later in this chapter. Therefore, the occurrence of any trait or ability is likely to be multifactorial; that is, it depends on many factors. In addition, any one gene may influence a variety of outcomes. This is referred to as pleiotropic effects. For example, one gene has been implicated in both lung capacity and high blood pressure in African Americans and with risk of heart attack in European Americans (Tyler, Crawford, & Pendergrass, 2014).

Polygenic inheritance: Numerous genes may interact to promote any particular trait or behavior.

Pleiotropic effects: The many different influences any single gene may have.

T/F #4

Every gene in your body has one specific function. False

A specific type of pleiotropic effect occurs when some genes or combinations of genes seem to have a general effect on many related abilities. These have been labeled generalist genes. For example, genetic analyses have shown that the same genes that influence verbal abilities also influence nonverbal cognitive abilities (Trzaskowski, Shakeshaft, & Plomin, 2013). Researchers believe they will find a set of many genes, each having a small effect, that together exert a general effect on a range of cognitive abilities (Trzaskowski et al., 2013). Therefore, although scientists have identified the functions of some individual genes, we must be careful not to oversimplify the findings that emerge as research continues.

Generalist genes: Genes that affect many apparently distinct cognitive abilities.