The organism possessing less adaptive trait in a certain natural condition will be eliminated. this is called

a) Natural Selection

b) Genetic drift

c) Natural elimination

d) Diffusion

The organism possessing less adaptive trait in a certain natural condition will be eliminated. This is called as Natural Selection.

Darwin did not believe that evolution follows a predetermined direction or that it has an inevitable goal.  His explanation that evolution occurs as a result of natural selection implied that chance plays a major role.  He understood that it is a matter of luck whether any individuals in a population have variations that will allow them to survive and reproduce.  If no such variations exist, the population rapidly goes extinct because it cannot adapt to a changing environment.  Unlike Lamarck, Darwin did not believe that evolution inevitably produces more complex life forms and that the ultimate result of this process is humans.  These were shocking, revolutionary ideas even for scientists who accepted evolution.


Today we use the term adaptive radiation to refer to this sort of branching evolution in which different populations of a species become reproductively isolated from each other by adapting to different ecological niches click this icon to hear the preceding term pronounced and eventually become separate species.


Darwin came to understand that any population consists of individuals that are all slightly different from one another.  Those individuals having a variation that gives them an advantage in staying alive long enough to successfully reproduce are the ones that pass on their traits more frequently to the next generation.  Subsequently, their traits become more common and the population evolves.  Darwin called this "descent with modification."


The Galápagos finches provide an excellent example of this process.  Among the birds that ended up in arid environments, the ones with beaks better suited for eating cactus got more food.  As a result, they were in better condition to mate.  Similarly, those with beak shapes that were better suited to getting nectar from flowers or eating hard seeds in other environments were at an advantage there.  In a very real sense, nature selected the best adapted varieties to survive and to reproduce.  This process has come to be known as natural selection.