Origin Story: A Big History of Everything

by David Christian

a few minutes after the big bang, our universe consisted of vast clouds of dark matter in which were embedded crackling plasmas of protons and electrons with photons of light flowing through them. Today, we find plasmas only in the centers of stars.

The second law of thermodynamics tells us that, in the very long run, all free energy will turn into heat energy.

Hydrogen bonds play a fundamental role in the chemistry of life because they account for much of the behavior of genetic molecules such as DNA.

complex adaptive systems, such as bacteria, your dog, or multinational companies, act as if every component is an agent with a will of its own, so each component is constantly adjusting to the behavior of many other components. And that yields extremely complex and unpredictable behaviors.

In such a chemically rich environment, many of the simple molecules from which life is built can form more or less spontaneously. We are talking about small molecules, with less than a hundred atoms, including the amino acids from which all proteins are made, the nucleotides from which all genetic material is made, the carbohydrates or sugars that are often used like batteries to store energy, and the fatty phospholipids from which cellular membranes are built.

Respiration is the reverse of photosynthesis and is really a way of releasing solar energy that has been captured and stored within cells through photosynthesis.

Eukaryotes also contain many internal organelles, like cut-down versions of the hearts, livers, and brains of animals. The most important of these are the mitochondria that some eukaryotes use to tap the rich energy of oxygen, and the chloroplasts that other eukaryotes use to tap the energy of sunlight through photosynthesis.