As my books Focus and Second Focus attest, I used to be a staunch opponent of evolution. I don't think that I ever considered it to be heretical, or even severely theologically problematic; I hadn't actually given much thought to the theological issues. Furthermore, I was aware that Rav Kook held of it, and although Rav Kook didn't count for much as far as I was concerned back then, I figured that it precluded rating evolution as kefirah. But most of all, refusing to declare it kefirah enabled me to make a statement that I thought was very impressive: "I'm not against evolution for religious reasons - I'm against it for scientific reasons!"
I had read the anti-evolution books by Michael Denton and Phillip Johnson, and they seemed extremely convincing. But, looking back now, I realize that there were more powerful, subconscious reasons for me to oppose evolution. I had "flipped out" in yeshivah, and I wanted to show why the Torah True Worldview that I had absorbed was so vastly superior to everything else out there. I was joining a social group which had a siege mentality, where we had to show how wrong the rest of the world was in order to feel good about ourselves. But I had to feel sophisticated, so it was important to convince myself that I was objecting to evolution solely on scientific grounds.
It was approximately in the fall of 1999 that my views on the topic changed. I don't remember exactly what the sequence of events was, but I remember the various factors that were involved.
One factor was that I was studying Daas Chochmah U'Mussar by Rav Yerucham Levovitz. He had some chapters about how it is more important and impressive for Hashem to work through natural law than through supernatural miracles. This was an astonishing chiddush to me, but I found his presentation persuasive. It took a while to internalize it, but it eventually was to make all the difference between wanting to find a scientific explanation for phenomena (as the rationalist Rishonim preferred), and wanting to find problems with any scientific explanation (as I had been taught to do until then).
At about the same time, I was contemplating evolution, and I thought about it in some critically important new ways. Until then, all I had focused upon were the problems with evolution. But now, I started to think about what had actually happened instead. I always accepted that the world was billions of years old; it was clear that there many eras of life. So, if evolution was false, then what was happening? Were new creatures popping out of the ground every few hundred years? I had no problem with supernatural miracles - I was hardly a rationalist at the time. Still, while I readily accepted supernatural events in the context of such extraordinary periods as the Exodus, it seemed incongruous for them to be taking place throughout millions of years of dinosaurs and early mammals. Furthermore, based on what I had learned in Daas Chochmah U'Mussar, it seemed that Hashem would have much preferred to use pre-existing animals as the raw material with which to make new animals, then to start entirely from scratch each time, which would require more supernatural intervention.
Another critical aspect in the evolution of my thought was that I was getting in the hang of breaking down complex issues into their components. With evolution, this meant distinguishing between common ancestry and evolutionary mechanisms. I realized that these were two very different things, and that most of the anti-evolution arguments I had were against the latter, not the former.
The final critical component was my realization that I was looking at the entire topic in the wrong way. As mentioned earlier, I had solely focused on the problems with evolution - the kashyas. This was exactly what Denton and Johnson had done in their books. As far as I was concerned, the existence of these problems showed that evolution was bogus. But I realize that this wasn't the correct way of looking at things. The correct way was to ask whether the existing evidence better supported evolution or special creation. And this radically changed my perspective on it.
For example, previously, I had only thought about the fossil record in terms of hoaxes (such as Piltdown man), and in terms of missing links. But now I realized that the fossils that we do have - primitive hominids, and the remains of millions of extinct species that are intermediate in form to surviving species - fit far, far better with the evolutionary model than with the special-creation model. The missing links were much less significant than the present links!
I still had, and still have, plenty of questions about evolutionary mechanisms. In an early draft of The Science Of Torah, I wrote about them at length. But one of the rabbonim that I showed it to for a haskamah (ironically, he retracted his haskamah as a result of the ban) made me take that part out. He told me that even if the Darwinian mechanisms were inadequate, presumably Hashem had some sort of means of transforming creatures via natural law, which science would eventually discover. Dissing the neo-Darwinian explanation would mislead people into thinking that it necessarily happened in a supernatural manner.
Together with further contemplation of the topic, in which it occurred to me that the "random" nature of Darwinian evolution was no more theologically problematic than the "random" nature of the events of Purim or of a lottery, I realized that it didn't make a whit of theological difference which mechanism powered evolution. As a result, I lost all interest in whether the neo-Darwinian explanation of the mechanism made sense or not. It was no more relevant to me than any other obscure problem of science. (And it's pretty clear that the reason why it's so relevant to Rabbis Shafran, Menken and Rosenblum is that it is anything but a solely scientific issue for them.)
Eventually I came across all kinds of other evidence for evolution, which I outlined in The Challenge Of Creation. A lot of people are clearly interested in my take on this topic, yet, strangely, have not read that book. I recommend it!