At least we might be the only species which is able (and on a good way) to make the planet inhabitable for itself. Actually, it nearly happened on a smaller scale a few decades ago. Ever heard of the Khmer Rouge regime? They almost managed the first autogenocide in humanity as the killings of their leadership affected foreigners only to a lesser extent, but was directed at their own population. If they caught a "traitor" (like someone with glasses, someone with education, someone who dared to admit that the production requirements weren't realistic) they beat him until he gave names of "accomplices" and killed him. The accomplices were treated the same way, so it became a self-fulfilling process.