MCAS Biology Practice Test 2025 – Complete Exam Preparation

Natural selection refers to the process by which organisms that are better adapted to their environments tend to survive and reproduce more effectively than those that are less well adapted. This mechanism results in the advantageous traits becoming more common in the population over generations. For example, consider a population of rabbits where some are faster than others. In an environment where speed is crucial for escaping predators, the faster rabbits are more likely to survive and reproduce, passing on their speed traits to their offspring. Over time, this leads to a population of rabbits that are predominantly faster.

Natural selection is a key mechanism of evolution and operates on the principle that environmental pressures can influence which traits are favorable for survival and reproduction.