How does the environment affect the traits of genetically identical organisms?

Even when organisms are genetically identical—such as clones or identical twins—they can exhibit significant differences in their phenotype, which refers to their observable physical, physiological, or behavioral traits.12

These variations occur because an organism's development and ultimate characteristics are shaped by the interaction between its genetic endowment and its environment. While genetics provides the blueprint, environmental factors—such as nutrition, temperature, light, humidity, and social experiences—can influence how those genes are expressed.13

For example, research on plants has shown that genetically identical cuttings grown in different environments (such as varying altitudes) develop and survive differently based on their specific surroundings. Similarly, in humans and animals, individuals with the same genetic makeup may grow, develop, and behave in distinct ways when placed in different environments. Consequently, diversity in almost any trait is the result of a complex interplay between hereditary variables and environmental influences.1