Question

All of the following statements is true about the principle observations upon which Darwin based his theory of natural selection except

• A. The population size of a species would increase exponentially if all individuals that were born reproduced successfully.
• B. Populations tend to remain stable in size, aside from seasonal fluctuations.
• C. Environmental resources are limited.
• D. Individuals in a population vary extensively in their characteristics.
• E. Most of the variation observed among individuals in a population is due to environmental causes; thus, very little variation is heritable (passed on from parent to offspring).

Answer 1

The correct option is E Most of the variation observed among individuals in a population is due to environmental causes; thus, very little variation is heritable (passed on from parent to offspring).

According to Darwin’s theory of natural selection, all organisms have the potential to reproduce limitlessly irrespective of the fact that each species maintain a constant density over time. However, the struggle for existence, i.e. the competition among individuals for available resources to survive and reproduce, put a check on species density and maintains it at the constant level. Survival of fittest is unequal ability of individuals to survive and reproduce based on suitability of their inherited characters to prevailing environmental conditions. It imparts the reproductive advantage to certain organisms which account for major part of the gene pool of the species. Thus, natural selection favors the individual with survival and/or reproductive advantage over others under existing environmental condition. Accordingly, variation is present in the population. Thus, the correct answer is option E.