Did Darwin use the word evolution?

Answer 1

Not in the title of his magnum opus, "The Origin of Species by means of natural selection or the preservation of favored races in the struggle for life," but yes, he used the word.

From the Online Etymology Dictionary:

1641, "to unfold, open out, expand," from L. evolvere "unroll," from ex- "out" + volvere "to roll" (see vulva). Evolution (1622), originally meant "unrolling of a book;" it first was used in the modern scientific sense 1832 by Scot. geologist Charles Lyell. Charles Darwin used the word eight times in "The Origin of Species" (1859). He preferred "descent with modification," in part because evolution already had been used in the 18c. homunculus theory of embryological development (first proposed under this name by Bonnet, 1762), in part because it carried a sense of "progress" not found in Darwin's idea. But Victorian belief in progress prevailed (along with brevity), and Herbert Spencer and other biologists popularized evolution.

Answer 2

No. Darwin published his theory in the 1850s. The structure of the DNA molecule was not worked out by biologists until around the 1950s. Darwin was long dead before molecular Biology came into play to support his theory.