An organism’s characteristics are not solely determined by its genetic blueprint. Throughout its life, an individual develops various features and abilities influenced by its surroundings and experiences. These characteristics, distinct from those inherited from parents, represent an organism’s interaction with its environment.
Defining Acquired Traits
Acquired traits are characteristics that an organism develops during its lifetime. These traits emerge due to environmental influences, an individual’s activities, learning, or experiences, rather than being encoded in its genetic material at birth.
Acquired traits represent changes to an organism’s physical appearance or function, which are known as its phenotype. Unlike inherited traits, which are determined by genes passed down through DNA, acquired traits do not alter the underlying genetic code.
Common Examples of Acquired Traits
Many common examples of acquired traits can be observed across humans, animals, and plants. In humans, physical changes resulting from lifestyle are clear instances. For example, the increased muscle mass developed by a bodybuilder through consistent exercise and diet is an acquired trait, as it is not genetically predetermined. Similarly, calluses on the hands of a manual laborer or scars from an injury are physical alterations gained during life. Learned behaviors, such as speaking a language, riding a bicycle, or playing a musical instrument, also represent acquired traits, as these skills are developed through practice and experience.
Animals also exhibit numerous acquired traits, particularly through learned behaviors. A dog trained to perform tricks, or a bird that learns a specific song, demonstrates acquired abilities. Predators learning effective hunting techniques are further examples. Even physical changes like scars on a wild animal from past encounters are acquired characteristics.
Plants, too, display acquired traits influenced by their surroundings. A tree whose trunk grows around an obstacle, such as a fence or rock, exhibits an acquired physical modification shaped by its environment. The size and thickness of a plant’s leaves can change in response to temperature, and a lack of nutrients might lead to stunted growth. The color of certain flowers, like hydrangeas, can also be an acquired trait, varying based on the chemical composition of the soil.
Why Acquired Traits Are Not Inherited
Acquired traits are not passed down from parents to offspring because the changes occur in somatic cells, not germline cells. Somatic cells are the body cells that make up an organism’s tissues and organs, such as muscle, skin, or brain cells. When an individual develops an acquired trait, like stronger muscles from exercise or a scar from an injury, these changes affect only the somatic cells.
In contrast, germline cells are the reproductive cells, specifically sperm in males and eggs in females. These cells transmit genetic information from one generation to the next, containing the instructions for inherited traits.
Changes to an organism’s somatic cells do not alter the DNA within its germline cells. Therefore, the characteristics acquired through environmental interaction or learning are not genetically encoded and cannot be passed on to future generations.