My sister, who works at a university, received an invitation from a group "dedicated to the promotion of evolutionary theory, science and reason" to discuss "the continued significance of Darwin's ideas" on Darwin Day (today).
Darwin's ideas did indeed have a great impact on the last century, but I suspect they won't be discussing some of the more tragic aspects of that impact. Consider these excerpts from The Descent of Man (as quoted in 10 Books that Screwed up the World):
With savages [i.e., those in more primitive societies], the weak in body or mind are soon eliminated; and those that survive commonly exhibit a vigorous state of health.... We civilized men, on the other hand, do our utmost to check the process of elimination; we build asylums for the imbecile, the maimed, and the sick; we institute poor-laws; and our medical men exert their utmost skill to save the life of every one to the last moment. There is reason to believe that vaccination has preserved thousands, who from a weak constitution would formerly have succumbed to small-pox. Thus the weak members of civilized societies propagate their kind. No one who has attended to the breeding of domestic animals will doubt that this must be highly injurious to the race of man. It is surprising how soon a want of care, or care wrongly directed, leads to the degeneration of a domestic race; but excepting in the case of man himself, hardly any one is so ignorant as to allow his worst animals to breed....
If...various checks...do not prevent the reckless, the vicious and otherwise inferior members of society from increasing at a quicker rate than the better class of men, the nation will retrograde, as has occurred too often in the history of the world. We must remember that progress is no invariable rule....
Darwin wasn't crazy. These ideas reasonably follow from "evolutionary theory, science and reason" when one begins by rejecting the ideas that God exists, that He created us in His image, and that we are therefore intrinsically valuable as individuals (weak or strong), not just as a species. When the survival and upward progression of the species is seen as the goal, the group is far more important than any specific individual. And suddenly, some of those individuals are just in the way.
Darwin's naturalistic theory with all its implications flowed quickly into all of Western culture. Those implications can be seen once again in a 1914 high school biology textbook, A Civic Biology, Presented in Problems:
If the stock of domesticated animals can be improved, it is not unfair to ask if the health and vigor of the future generations of men and women on the earth might not be improved by applying to them the laws of selection.... The science of being well born is called eugenics.
Those who said such things were not regarded as monsters in the academic world. This approach was pure reason. If there is no God and we are just animals, why shouldn't we breed humans as we breed animals? Why shouldn't we let the weak die for the common good? Why shouldn't we end their lives for them if their existence threatens our progression as a whole? Rational thought within a naturalistic framework won't give you an answer; Darwin's rational thought tells us that value lies in the health of the group--in the survival and thriving of the best of the species, not in a single, weak person. In the interest of promoting our own evolution, of creating our own super-men and utopian societies, sacrifices must be made.
And they were. By the millions. A look back through the past century shows the impact Darwin's ideas can have when followed to their logical conclusion. There is no real foundation for human value in a Darwinist worldview. Although the habit of compassion lingers in our civilization (as Darwin lamented in the quote above), we must remember that compassion for the weak "is no invariable rule." It requires a foundation. If compassion for "the imbecile, the maimed, and the sick" is to continue, it must be grounded by a different kind of worldview altogether.