Final answer:
Charles Darwin's theory of 'descent with modification' is driven by heritable traits that enhance an organism's survival and reproductive success, leading to natural selection and evolutionary change.
Step-by-step explanation:
Charles Darwin proposed that "descent with modification" resulted when organisms of a particular species become adapted to their environment because they possess heritable traits that enhance their survival and reproductive success in the local environment. This concept is a central tenet of Darwin's theory of natural selection. In the process of natural selection, individuals with traits that confer advantages in their environment are more likely to survive and reproduce, passing these adaptive traits to the next generation. Over time, these traits become more common within the population, leading to evolutionary change.