If a single cell, under the appropriate conditions, becomes a person in the space of a few years, there can surely be no difficulty understanding how, under appropriate conditions, a cell may, in the course of untold millions of years, give origin to the human race. [herbert spencer]

This survival of the fittest implies multiplication of the fittest.

Explanation:

Herbert Spencer said “If a single cell, under appropriate conditions, becomes a man in the space of a few years, there can surely be no difficulty in understanding how, under appropriate conditions, a cell may, in the course of untold millions of years, give origin to human race.

Life span, the period of time between the birth and death of an organism. It is a commonplace that all organisms die.

The exact duration of human life is unknown, although there is presumably a maximum life span for the human race established in the genetic material. At first thought, this statement seems irrational. Surely no human can live 1,000 years. Even though all may agree that the likelihood of an individual living 1,000 years is infinitesimal, there is no scientific proof that this statement is or is not true.

a. the production of carbon dioxide through the process of photosynthesis