Natural selection is best described as:

• A. The survival of the fittest organisms in their environment
• B. Random changes in the genetic code
• C. A method of artificial breeding
• D. Uniform adaptation across all species

Answer: (A)

Natural selection is best characterized as the process through which the organisms best suited to their environment are more likely to survive and reproduce. This concept hinges on the idea that certain traits, which may provide advantages in survival or reproduction, become more common in a population over time. In this context, "survival of the fittest" is a phrase that encapsulates this principle, indicating that fitness refers to an organism's ability to adapt to its environment and have reproductive success.

This mechanism is critical for evolution and explains how species adapt to changing environments. Traits that enhance survival and reproductive success are passed down to subsequent generations, leading to evolutionary change. In contrast, options that discuss random genetic changes, artificial breeding, or uniform adaptation do not accurately capture the essence of natural selection; thus, they do not fit the fundamental definition of the process.