A pleiotropic gene refers to a gene that controls multiple traits in an individual. It is not related to the time of its evolution or its expression in specific organisms. Let's discuss the answer in detail:

Explanation:
1. Pleiotropy:
- Pleiotropy is a phenomenon where a single gene has multiple effects on an individual's phenotype.
- This means that a single gene can influence the expression of multiple traits or characteristics.
- These traits can be diverse and may include physical features, physiological processes, or even behavioral traits.

2. Genes and Traits:
- Genes are segments of DNA that provide instructions for the development and functioning of an organism.
- Traits are observable characteristics of an organism, such as eye color, height, or the presence of a certain disease.

3. Example:
- To understand pleiotropy, let's consider an example of a gene that controls both hair color and eye color in humans.
- If this gene is altered or mutated, it may result in a person having a different hair color and eye color than what is typically observed.
- In this case, the gene is pleiotropic because it affects multiple traits (hair color and eye color) in an individual.

4. Importance of Pleiotropy:
- Pleiotropy plays a crucial role in the development and evolution of organisms.
- It allows for the coordination of multiple traits under the control of a single gene, which can have advantages in terms of genetic efficiency and adaptability.
- However, pleiotropy can also have negative consequences, as mutations in pleiotropic genes may lead to the development of genetic disorders or diseases.

In conclusion, a pleiotropic gene controls multiple traits in an individual. It is not limited to a specific time of evolution or expression in certain organisms. Pleiotropy is a fundamental concept in genetics and is important for understanding the complex relationship between genes and traits.