Question

What are Darwin's four observations concerning natural selection? List and briefly explain each one with an example. How does natural selection impact evolution?

Your response must be a minimum of 200 words.

Answer 1

Question: what are the Darwin's four observation concerning natural selection

Sol: Darwin coined the term natural selection to described the process by which organisms with favorable variations survive and reproduce at a higher rate. Darwin's theory of natural selection is based upon the following four fundamental propositions:

1. Struggle for existence: According to Darwin's, individuals multiply in geometric ratio, whereas space and food remain almost constant. That leads to competition between individuals of the same species because all use the same limited resources.

2. Survival of the fittest: During the struggle for existence only those individuals having advantageous variations are more likely to survive and reproduce than those without the advantageous variations.

3. Variation: No two individuals are exactly the same, rather every population displays enormous variability.

4. Origin of new species: From above observations Darwin made certain conclusions and summarized them under the heading origin of species by natural selection. As a result of struggle for existence, variability, and inheritance, the successive generations tend to become better adapted to their environment and ultimately lead to the origin of new species from the old ones.

Example that supported the natural selection is industrial melanism in peppered moth.

Natural selection impact the evolution: Over the generation the process of natural selection wil lead to a continuing gradual change of populations, that is Evolution, and to production of new species. Example- Heritable variation in neck length exists in the ancestral population of giraffe, during the times of food scarcity the longer neck individuals are able to exploit food resources that is unavailable to the shorter neck individuals, after many generations of this selective process the descendant population has a much longer average neck length.