Dogs and Love, Part 1
Glen Allport at Strike the Root - what Mr. Allport's dog has taught him about love and the nature of reality. [root]
My idea of "original sin" -- to the extent such a concept could have any meaning for me -- would be the evolutionary discovery that killing and eating another organism is an efficient way to obtain nutrients. From that point on, millions of species have evolved with murder of other animals as their primary or only means of obtaining food. Think, for a moment, what that actually means: hundreds of millions of years (so far) of horrifying, bloody murder as the essential basis for much of the life on this Earth.
Add parasites and disease, and you have a perfect trifecta of horror: life as a vision of hell. (Not to mention starvation, thirst, freezing cold, aging, and other hardships, but those do not involve one life murdering or tormenting another.) The one proof I find truly persuasive against an omnipotent, loving god (or against intelligent design, by anything but a race of alien sociopaths) is this widespread, basic use of murder to obtain food. One can easily imagine designing an ecology where murder of anything sentient is genetically forbidden, and where all life forms are either vegetarians, scavengers, or capable of photosynthesis or some other process that enables life without requiring murder. One could also imagine an ecology where parasites and disease are missing or at least more often benign. Yet carnivores, parasites, and disease organisms are extremely well-represented among Earthly species. A loving, all-powerful being would simply not create such a nightmare. Evolution by natural selection absolutely would create this situation, however. Evolution cares nothing about pain or violence or anything else, because (as many have pointed out) evolution does not "care" at all. A species either lives and reproduces successfully, or it does not. Species that do survive change occasionally by mutation and the resulting slightly-new forms must survive the same test: live and reproduce, or die out.