Definition of Simile
In Chapter 3, Darwin uses personification and a simile to emphasize the incredible power of natural selection:
We have seen that man by selection can certainly produce great results, and can adapt organic beings to his own uses, through the accumulation of slight but useful variations, given to him by the hand of Nature. But Natural Selection, as we shall hereafter see, is a power incessantly ready for action, and is as immeasurably superior to man’s feeble efforts, as the works of Nature are to those of Art.
At the end of Chapter 4, Darwin summarizes his argument thus far with an extended simile and a metaphor comparing the evolution of life on earth to the growth of an old tree:
Unlock with LitCharts A+As buds give rise by growth to fresh buds, and these, if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever-branching and beautiful ramifications.
In Chapter 6, Darwin addresses several challenges to his theory of natural selection. He uses a simile to explain why his theory is not invalidated by the fact that unrelated animals sometimes share features, like wings:
Unlock with LitCharts A+As two men have sometimes independently hit on the same invention, so in the several foregoing cases it appears that natural selection, working for the good of each being, and taking advantage of all favourable variations, has produced similar organs, as far as function is concerned, in distinct organic beings, which owe none of their structure in common to inheritance from a common progenitor.
In Chapter 12, Darwin describes many possible ways plant seeds might be dispersed around the world. He uses a simile and imagery as he describes a swarm of locusts that may have introduced invasive plant species to Madeira through seeds in their dung:
Unlock with LitCharts A+The Rev. R. T. Lowe informed Sir C. Lyell that in November, 1844, swarms of locusts visited the island of Madeira. They were in countless numbers, as thick as the flakes of snow in the heaviest snowstorm, and extended upwards as far as could be seen with a telescope. During two or three days they slowly careered round and round in an immense ellipse, at least five or six miles in diameter, and at night alighted on the taller trees, which were completely coated with them.