Darwin's theory of Evolution is basically survival of the fittest. The strongest and most fit for their environment will dominate and reproduce passing along their genes to the next generation. The problem with this theory is that it is overthrown by technology.
However, Darwin wanted to shape evolution through the viewpoint of natural selection, and believes evolution is driven by natural selection. An individual that has traits that help it to adapt has a better chance of reproducing. The traits then have a good chance of being inherited by the offspring. Over time, traits spread among the species. Darwin noticed it in the beaks of finches. Those with beaks that could crack more variates of seeds, had a better chance of survival.
Evolution is change in species over time. Natural selection is the only scientifically recognized theory to explain it. Although, of course there are many details and fine points behind the idea of natural selection, the basic idea behind it is simple. It begins with the observation that children tend to be like their parents. From that observation one reproduces will tend to become more common in a population, whereas harmful heritable traits will gradually become less and less common. Of course, random changes to heritable traits ("mutations") may also occur, but these too will tend to become or less common depending on whether they are helpful or harmful. Finally, when we consider the large age of the Earth, this provides enough time for the accumulation - in fact all life on Earth.
That animals evolve to better fit their niche or lifestyle because those most fit in their niche tend to be the ones that pass on their genes to their offspring. We know that evolution is the change in a population over time. There are four mechanisms by which a population of organisms can evolve: Natural Selection, Genetic Drift, Mutations and Gene Flow. The driving force for evolution change has been a slow process for Humans, however we are still evolving.
Every generation our offspring of evolution shows up every 25 years. For examples some beetles are green, and some are brown. Since the environment can’t support unlimited population growth, not all individuals get to reproduce to their full potential. There is heredity they have brown baby beetles because, this trait has a genetic basis. If the trait becomes more common in the population the offspring of it will be brown.
Evolution is said through the shaping of natural selection is passed on from one generation to next. Living organism have gone down with moderation from species that lived before them. Therefore, if a species could pass on the same traits, their offspring could be better than the previous. In conclusion, evolution has been studied and offered an explanation as to where species come from and how they evolved in the manner that they did. This type of science has been studied for years and every scientist has come up with theory.