Because someone submitted them and others up voted them. Don't compain just flag it or ignore it.
There definitely seems to be a growing group of users who are looking to greatly expand the scope of this site and to me that dilutes the quality of the site.
2. If I ignore it, I'm not up voting it. I'm up voting posts that I think have some value.
3. This site is about whatever people on this site find interesting. If evolution (an interesting subject) happens to come up, it'll likely get up voted and discussed.
4. We get some slow days when it's mostly fluff here. And then we get days when it's nothing but academic math papers. It comes and goes, deal with it.
It most certainly does. A few days back I watched an article with hundreds of votes drop like a rock as the flags rolled in (it was fairly political, and I suspect it gathered a bunch of flags as soon as the flamewar started.) It went from near the top of the front page to approximately the fourth page in a matter of perhaps ten minutes.
One flag won't do much. But if enough other people agree with you that something doesn't belong, it'll disappear.
> "change the fundamental focus of this site from technology to animal evolution"
One reason you're not getting as much agreement as you might expect: the fundamental focus of this site is not technology. It's anything that gratifies intellectual curiosity. Technology and animal evolution both fall into that category, as do history, chemistry, mathematics, and occasionally even religion (not samey-samey stuff, but genuinely new discoveries or interesting topics -- like when the Vatican decided to create a giant digital archive, or when a guy did a Show HN about software he made for his church.)