Final answer:
Epigenetics is the study of how gene expression can be influenced by environmental factors and mutations, leading to heritable changes that affect a person's development and functioning.
Step-by-step explanation:
Epigenetics is the study of how gene expression can be influenced by environmental factors and mutations. These changes in gene expression can result in heritable changes in a person’s DNA that affect their development and functioning. For example, exposure to smoking in childhood has been shown to lead to shorter height in adulthood. Trauma can also have lasting effects on growth and increase the likelihood of specific maladaptations. Epigenetic changes can be inherited and can impact future generations, providing evidence of evolution occurring in real-time.