[Update: and now there's a fifth discussion thread, which you should probably use in preference to this one. Later update: and a sixth -- in the discussion section, which is where these threads are living for now on. Also: tag for HP threads in the main section, and tag for HP threads in the discussion section.]
The third discussion thread is above 500 comments now, just like the others, so it's time for a new one. Predecessors: one, two, three. For anyone who's been on Mars and doesn't know what this is about: it's Eliezer's remarkable Harry Potter fanfic.
Spoiler warning and helpful suggestion (copied from those in the earlier threads):
Spoiler Warning: this thread contains unrot13'd spoilers for Harry Potter and the Methods of Rationality up to the current chapter and for the original Harry Potter series. Please continue to use rot13 for spoilers to other works of fiction, or if you have insider knowledge of future chapters of Harry Potter and the Methods of Rationality.
A suggestion: mention at the top of your comment which chapter you're commenting on, or what chapter you're up to, so that people can understand the context of your comment even after more chapters have been posted. This can also help people avoid reading spoilers for a new chapter before they realize that there is a new chapter.
Error: Most of human history is a recounting of group selection in humans. Every time one group of people displaces another group by virtue of superior technology or social organization, that's group selection.
Having a belief in, or at least openness to, group selection, is one of my rationality tests.
In related news, this weeks Science has the clearest demonstration of group selection that I've seen: The ability to self-pollinate in plants gives individuals a great reproductive advantage; but also increases the likelihood of the entire species going extinct. The presence of a feature (self-pollination) that provides an advantage to the individual, provides a disadvantage to the species, that causes species-level selection.
I realize your views may have changed by now, but isn't that obviously caused by Red Queen effects? Just like all other sexual reproduction?