According to the work of Charles Darwin, the famous biologist, the animal and plant species that we see today have emerged due to millions of years of evolution. The process of evolution is guided by the principle of survival of the fittest, selecting the organisms that have a better chance of survivability. The plants and animals that we see today are the results of millions of years of adaptation to the constraints imposed by the environment. At any given time, a large number of varied organisms may coexist and compete for the same environmental resources.
The organisms that are most capable of both acquiring the resources and procreation are the ones whose descendants will have more chances of survival. Organisms that are less capable, on the other hand, will tend to have few or no descendants. Over time, the entire population will evolve, containing on average organisms that are more fit than the previous generations.
What makes this possible? What decides...