Life on Earth By aaron_maszko 200 3.5 Billion Years Ago - Single Celled Creatures form 400 0.55 Billion Years Ago - First multicellular organisms 406 0.36 Billion Years Ago - First Trees 407 0.25 Billion Years Ago - The First Mammals 412 0.0001 Billion Years Ago - The First Humans Jan 1, 2001 4.5 Billion Years Ago - The Earth is formed 4.5 Billion Years Ago
