"seems sad"? Did you even read what I wrote? I gave two separate and specific contexts where extinction is a clear loss to humanity: scientific loss in all cases, and cultural loss in more limited cases. Both go well beyond "seems sad".
, especially as it's often because of unnecessary predation by humans (e.g. elephants, rhinos),
Along with climate changes, desertification, habitat destruction, food chain collapse,...
. However, in general extinction is totally natural
Nobody is arguing that point. A meter striking a major city would be totally natural too. "Natural" is hardly a reason to simply let it happen if we see it coming.
and as in this (rare) case when it's not our fault at all, then let it be
It's still a scientific loss. And its a valuable species; all the Galapagos are particularly valuable to science due to their extended isolation and resultant independent evolution.
The question I'm asking is not whether its natural or not, its whether its better or not in the long run for us not to have access to this species to study?
Its hard to make the argument that we gain any advantage from it being extinct.
I suspect that those Iguanas will be perfectly fine if we just leave it alone for a change
We have actual scientists who have an actual scientific basis for being concerned about this species status... but you, without any grounds, studies, or special knowledge of the situation, suspect it will be just fine. So ... lets go with that instead. /facepalm