I am working my way through The Evolution-Creation Struggle, by Michael Ruse, a philosopher at Florida State. That's important: he's not a biologist for whom science can do no wrong and religion can do nothing right, he's a philosopher interested in a broader set of questions about the protracted debate between science and religion. I'll cover topics from the first half of the book in this post.
The first point is that evolution didn't start with Darwin. It was in the air ever since the Enlightenment produced a a general belief in the possibility of human progress. Christians could be as progressive as more secular thinkers. The idea that human effort could and should make the world a better place was a central tenet of postmillennialism and of the social gospel of the late 19th century.
How the notion of progress was incorporated into geology and biology is a messy tale. Scientists inherited the non-evolutionary worldview bequeathed by Plato and Aristotle as well as the short timeframe depicted in Genesis. Design was evident in plants and animals, which were and are well-adapted to their various environments. Early evolutionists like Erasmus Darwin (grandfather of Charles), Jean-Baptiste Lamarck, and Robert Chambers struggled to give explanations that accounted for the growing body of evidence showing similarities between different but related species, and also to account for the fossilized remains of many now-extinct creatures, including dinosaurs whose enourmous bones were discovered about this time. It didn't help that such evolutionary speculation was often made part of the social and political disputes of the day.
So by the time Charles Darwin was becoming a young naturalist, key work in related fields (Malthus in economics and demography; Lyell in geology) was just emerging. In 1831, Darwin rather boldly set out on a five-year mission to explore the flora and fauna of a new continent by signing on with the captain of HMS Beagle. Darwin did fine fieldwork, and his careful reflections on what he saw and collected changed his life. It changed everyone's life. Darwin also happened to be a good writer (he picked up rhetoric somewhere in his earlier education for the ministry), so when he finally got around to publishing The Origin of Species in 1859, it did what no earlier work on evolution had done: it made a sound and defensible scientific case for evolution.
But Darwin's theory was not widely accepted. The evidence for and discussion about evolution was not the problem for many readers, both secular and Christian. The problem was that almost no one agreed that natural selection, Darwin's mechanism, was sufficient to produce the sort of changes that a theory of evolution was supposed to explain. Geologists and physicists of that day put the age of the earth at a hundred million years, not sufficient time for the accumulated incremental changes posited by Darwin to accomplish the work of evolution. Other scientists proposed other mechanisms that were more widely accepted at the time. Darwin had no good candidate for a mechanism of inheritance (genetics did not emerge until the 20th century). When Darwin died in 1882, it was not at all clear that natural selection would end up being the primary driver of evolutionary change or that Darwin would attain the enduring scientific stature he has today.
But the best known evolutionist of the 19th century wasn't Darwin, it was Herbert Spencer. Where Darwin was always reluctant to make racial, social, or political pronouncements based on evolution or natural selection, Spencer and a host of others were quite happy to do so, although they rarely got the scientific details right. Social Darwinism, laissez faire economics, feminism -- the range of topics one could evolutionize was almost limitless. Eugenics, unbridled competition in industry, and militarization also made the list of popularized evolutionary applications. By the dawn of the 20th century, it was evident to many that progress, the social application of evolution, had a dark side ... and that was before World War I, genocide, and totalitarianism. The story of evolution in the 19th century did not end on a high note.
Upcoming topics: Christian responses to evolution; how science reclaimed evolution and natural selection; is evolution a secular religion?