Humanity

Humanity nearly became extinct 72000 years ago as human population plunged to just 40 'breeding pairs' due to a super volcanic eruption. Toba eruption dimmed the sun for six years, disrupted seasonal rains, choked off streams and scattered whole cubic miles of hot ash across acres and acres of plants and trees, killing them. Humans are genetically less diverse than most species largely due to this (and possibly others) bottleneck event.