has a funny but inaccurate post on the relationship between Darwin and the Holocaust, as described in Ben Stein's "Expelled!" You can read my major criticism there, but I have one more comment:
Too often, in discussing the evolution/intelligent design debacle and the supposed link between Darwinism and eugenics, euthanasia, abortion, the Holocaust and the death of Santa Claus, both sides ignore historical fact and basic reason.
The Good Guys
I'll count evolutionists as the "good" guys because I'm biased in their favor, because evolution is the better theory and because I can. It's my blog, after all.
Too many evolutionists, like PZ Myers and Richard Dawkins, stray from the science of evolution to historical and ideological arguments that are either irrelevant to the debate or tremendously weak in fact and in logic. They are far more interested in scoring ideological points for the "New" Atheism than in defending good science from bad ideas.
Others, as is the case with Evolving Thoughts, ignore the difference between linking Darwin to the Holocaust and other events and movements of the 19th and 20th centuries and blaming Darwin for anti-Semitism or genocide in general. Yes, anti-semitism and genocide preceded Darwin, but his ideas were influenced by and contributed to the development of scientific racism, which influenced the nature of these movements/events.
Darwin, like many prominent scientists, believed that the preservation of the weak (those with physical and mental defects) impeded human evolution and that human evolution would advance through "civilized races exterminating and replacing the savage races." His moral opinion was a different thing altogether. He opposed eugenics and genocide.
Those who were influenced by Darwin's theories and scientific racism in general drew upon the "factual claims" and ignored many scientists' moral compunctions against certain actions. Sir Francis Galton, Darwin's cousin, drew on his work to create Eugenics but the applications of the theory and its prescriptions for human society were often in contradiction to Darwin's own moral views and occasionally a distortion of Darwin's factual claims. (More on all below.)
The Bad Guys
The I.D. popularizers are more concerned with rhetoric than with fact and science.
There is no direct line between Darwin and the "evils" of the 20th century. Abortion, for one, is ancient and, in the majority of cases, has more to do with the individual woman's circumstances than with any scientific argument based on "survival of the fittest". (Abortion of "defective" fetuses may have some links to Eugenics but mostly has to do with people deciding that they don't have the mental, physical or economic resources to cope with a disabled child.) A wide variety of events and ideas led to the Holocaust: from Germany's defeat in WWII and its subsequent political/economic collapse, to long-standing religious bigotry, to nationalism and the desire to build an unbeatable and authentically German Germany, to power politics, to xenophobia. Eugenics we've covered, but it drew just as much from statistics, socioeconomic and class biases, the work of philosophers like Plato, and ancient Greek/Roman practices of infanticide than from Darwin and evolution.
Finally, they equate Darwinism with modern evolutionary biology, which began with Darwin but has now moved light years beyond him. Science has done what science does, corrected theory based on new discoveries. It will continue to do so as scientists attack each of the flaws in the modern theory.
UPDATE: Just for "insurance," I'd like to make the distinction between influenced and caused. Richard Dawkins says that "Darwin made it possible to be an intellectually fulfilled atheist", but Darwin by no means created atheism. His work, however, influences how atheists view the world and provides what some atheists "interpret" as "proof" that there is no G-d.
Darwin influenced the development of Western ideas about race and human nature, both good and bad, but he by no means caused the moral, social, cultural, historical and political factors that made appropriations/distortions of his work so appealing or so effective. In the same circumstances, the Nazis probably would have done the same thing. Their arguments and methods would have been very different, but their actions probably would have been generally the same.