Final answer:
The Theory of Evolution by Natural Selection explains how biological adaptations in organisms come about through a process where advantageous traits become more common in populations over generations in response to environmental changes.
Step-by-step explanation:
The term for the theory that biological adaptations in organisms occur in response to changes in the natural environment and develop in populations over generations is known as the Theory of Evolution by Natural Selection. This theory articulates that species evolve over time due to variations in traits, which make certain individuals more likely to survive and reproduce in their changing environments. These advantageous traits become more common in the population over many generations, leading to the adaptation of the species to its environment.
It's crucial to understand that it is the population, not individual organisms, that evolves over generations. Also, the process is not intentional but rather a natural consequence of certain individuals with favorable traits reproducing more successfully than others. Over time, these cumulative reproductive differences can lead to significant changes within the species.