The Making of Life on Earth: From the first chemistry to the present biosphere, step by step
Year: 2026
Type: preprint
Abstract: Life on Earth is a single lineage that began from chemistry, perhaps within two or three hundred million years of the first oceans, and has since rebuilt the planet that made it. This paper follows that history in order. It starts with the building blocks, some delivered from space and some made on the young Earth; follows them into short strands of RNA, molecules that copy themselves, membrane-bound protocells, the genetic code and proteins, and DNA; and arrives at the last universal common ancestor of all living things, estimated at about 4.2 billion years ago. It then traces what life did to the oceans and the air: methane and carbon dioxide in a world without oxygen, nitrogen drawn from the air, the invention of oxygen-producing photosynthesis, the Great Oxidation Event beginning 2.43 billion years ago, the rusting of iron out of the oceans, the ozone layer, complex cells, two global glaciations, the first animals, calcium skeletons in the Cambrian, plants and forests on land, five mass extinctions, the cooling Cenozoic, and the arrival of humans. It ends with the present, in which one species has raised atmospheric carbon dioxide from about 280 to 432 parts per million, and with the recent acceleration of understanding, including artificial intelligence, the human need for energy, and the return to the air of carbon that life buried over hundreds of millions of years. It makes no claim about the future of Earth or of life on it. A timeline and an element-by-element table record what happened when and what life did to each element. Life has been present for more than nine-tenths of Earth's history, animals for about the last eighth of it, and Homo sapiens for less than one ten-thousandth. Every quantity is imported from the sciences of life and Earth. The contribution is the ordering: one continuous record from the first chemistry to the present biosphere, read alongside the planet it changed.
Author: Sanders, Nicholas Archer
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7224110214