I see somewhat of an analogy now between this and Clarke's Cradle. The theme of a very physically and abruptly changing humanity.

What I do wonder, though, is why, in this entire story, nobody ever seriously considered the option of just leaving each other be. Live and let live and all that. It seemed rather obvious to me. Three species meet, exchange what they will, and go their own separate ways. After all, morality is subjective, and any species that understands the prisoners dilemma should understand that as well. All they had to do was walk away.