The surah al-Fath (victory/conquest) wasn't revealed due to the conquest of Makkah! This surah was revealed immediately after the peace treaty of Hudaybiyyah. According to the Quran it was not the war, but peace that was the real victory.
Every creature on the earth is an ayah/verse (proof) for Allah. Every species, which is exterminated, is an extinction of one of Allah’s ayahs. A creature is an ayah for Allah, whether it's alive or dead.