Life on Earth BeginsRoughly four billion years ago, life on Earth emerged as the first cells formed, most likely at hydrothermal vents, before evolving to explore new biomes. The new study investigated protein structures, chemical reactions, and genomes involved in the evolution of these early free-living cells. The Energy for Life on EarthA primary question involves what supplied the energy driving metabolic reactions in early life on Earth. The researchers identified a new energy source in palladium, a natural catalyst used by chemists and also plentiful in hydrothermal vents. Only free-living cells are alive.”