Well, it's that day again, and for a nice round number, too: It's #200. My opinion about Darwin isn't much different than it was for #199. Darwin was a great guy who planted some of the seeds for our best explanation for life's diversity.
But that's it. He's not a saint to me. He's not a prophet. He's just a guy who came up with a useful idea and did some of the legwork to demonstrate its truth. The same's true of Newton, Einstein, Copernicus, and all the great scientists. They're people just like us. They're fallible, but they and their successors checked their work and actively tried to shoot down the ideas as they ended up standing firm when the evidence kept going their way.
Darwin could easily have been wrong. If heredity turned out to be continuous instead of made of discrete genes, for example, his idea would have been on much shakier ground, and possibly outright falsified. We wouldn't be celebrating his memory today in that instance. All the time, people come up with ideas that are simple, elegant, direct, and, unfortunately, wrong. Those who do the tests necessary to find out that they're wrong deserve a bit of respect for giving it an honest go. Darwin was one of the lucky (and, of course, smart) people who's turned out to be right.
Of course, Darwin wasn't right by virtue of being Darwin. It's the accumulation of evidence that says he was right about natural selection. Of course, he had some inaccuracies that have been and are still being ironed out by modern scientists, who are continually tweaking the details to get an ever more accurate picture. So, we celebrate him as a guy who got us started on a right track, not some magical gnome who poofed us to the destination.
Meanwhile, Darwin's and our chief opponents, IDiots, are having about as much success as psychics.