The series repeatedly frames this passage as evidence of Darwin's "fundamentally religious" view of nature. But later in life Darwin explicitly disavowed this view of nature's "grandeur." Furthermore, the words "by the Creator" only showed up in the second edition of the Origin, released several weeks after the first. Why this change? Because after Darwin came under vicious attack for his views—science versus religion—he went back and stuck in references to God as a form of appeasement. Evolution, possibly unaware of the Origin's different texts, uses the original sentence at the close of "Darwin's Dangerous Idea" but the more godly version at the close of "What About God?"
After the publication of the Origin, Darwin steadily grew even more skeptical. In his autobiography, begun in 1876, he puzzled through various arguments for the existence of God, but finally concluded, "I for one must be content to remain an Agnostic." PBS never cites this passage, perhaps because it puts Darwin far closer to Daniel Dennett and Richard Dawkins than rare theistic evolutionists like Kenneth Miller. The series strives to present a charming picture of a scientific theory that leaves religion relatively unchallenged, but Darwin's life itself suggests otherwise.