Charles Darwin has worked out a theory of evolution according to which all the species are united by a common ancestor. There exist some objections to this theory. These are mostly philosophical objections of those who claim about the existence of immutable essences stating that there are certain variations within any species (Ruse, p. 237). The core of Darwin’s theory of Evolution is the Evolution by Natural Selection. According to this theory, only those organisms which are able to easily adapt to the existing environment are able to survive. In other words, those organisms which are stronger get a chance to live and propagate by means of genes mutation (again, letting the stronger individuals to survive). This theory was based on Darwin’s assumptions rather than observations because until the 20th century genes, DNA, and the process of heredity were unknown to the scientists (Weber, p. 345). Darwin’s theory of Evolution by Natural Selection cannot be considered erroneous because stronger organisms are able to survive by means of adaptation to a new environment and even the variations in species can become beneficial for them; the theory has its limitations but most of them can be explained.
To begin with, the theory of Evolution by Natural Selection is correct because numerous examples show that only those organisms which are able to adapt to new environment can survive. For instance, certain plants, such as cactuses grow even in desert where the temperature is extremely high and the rains are a rare occurrence. Cactuses may be regarded as stronger species which, unlike all other plants, managed to adapt to high temperature and rare watering. The same can be true about camels. A regular animal, such as a dog, will not be able to survive in the desert without water, while camels who adapted to the environment in the process of evolution can live without water up to forty five days.
What’s more, variations within certain species let them accustom to new environment and sustain their species while other organisms may not survive. These variations can be referred to as “temporal differences in lineages” (Gould, p. 25). Under certain conditions, the amount of variation individuals within the species can get bigger, but when the conditions return to those which they used to be, the variations will get balanced again. For example, the number of birds with heavy beaks may increase during dry years because these birds can break shells and tree bark more easily than the birds with normal beaks. Nevertheless, when the drought will be over, the birds with heavy beaks will diminish.
However, there are cases when the Evolution by Natural Selection cannot be applied. This concerns the cases when strength of certain organisms depends on side factors. For instance, no evolution takes place when some species of plants propagate not because of their genes but because of the soil they grow in. The same is applicable to animals; if some of the species are fleeter due to genes mutations but the predator is a thousand times faster, then no evolution will take place (for example, if cheetahs could eat snails).
In sum, Darwin’s theory of Evolution by Natural Selection is not erroneous because a number of examples show that only those organisms which are stronger and which are able to adapt to changing of environment are able to survive. The theory is not applicable when the evolution of the organisms depends on side factors.
Works Cited
- Gould, Stephen J. The Mismeasure of Man. Norton, 1996.
- Ruse, Michael. The Darwinian Revolution: Science Red in Tooth and Claw. University of Chicago Press, 1999.
- Weber, Alan S. Nineteenth Century Science: a Selection of Original Texts. Broadview Press, 2000.