If you were to store all the information contained in all the DNA of every organism on Earth, you would need to find a pretty big data-farm. It would require the equivalent capacity of 1 billion trillion supercomputers, according to a a new estimate–the first to count all of the genetic code on the planet.
Fifty trillion trillion trillion “base pairs”–the chemical letters making up genetic code–underpin all living things, say Hanna Landenmark, Duncan Forgan and Charles Cockell, authors of a paper published in the journal Plos Biology. All of this DNA weighs 50 billion metric tons and is enough to fill 1 billion shipping containers.
The point of the estimate isn’t trivial interest. It’s a step in seeing the “biosphere” as an informational system, with potential implications for all kinds of science, say the authors. “The biosphere can be visualized as a large, parallel supercomputer, with the information storage represented by the total amount of DNA and the processing power symbolized by [gene expression] rates,” they write. “In analogy with the Internet, all organisms on Earth are individual containers of information connected through interactions and biogeochemical cycles in a large, global, bottom-up network.”
Landenmark, Forgan and Cockell propose an “alternative way of quantifying and understanding biodiversity” based around counting the total DNA in an area, rather than counting up species and the number of individuals representing those species. “The corresponding action in the electronic computer analogy would be to attempt to estimate the information content of the Internet by counting the number of models and number of computers attached to it,” they say of current biodiversity calculation efforts.
To reach their numbers, the researchers split living things into five categories: prokaryotes (single cell organisms), plants, animals, unicellular eukaryotes, and fungi, then estimated biomass, number of individuals, and DNA densities.
The approach isn’t very poetic. It reduces human beings to nothing but “containers, within which the information that underpins the functioning of the biosphere is stored as DNA.” But they say this could be useful for understanding how the biosphere has changed over time, or could change in the future.