This May Be the Best Definition of "Life". It's Surprisingly Simple
Definitions of "life" are a dime a dozen. In a paper published back in 2011, University of Haifa biophysicist Edward Trifonov documented 123 of them. But which one is best? Trifonov decided to seek the answer in a unique way.
Rather than skeptically nitpick each and every definition, pinpointing a single winner, Trifonov did something different. He combined them. He imagined bringing all of the authors – some separated by centuries – together and having them hash out their differences to formulate a single, crowdsourced definition of life. However, lacking the requisite abilities of time travel and resurrection, Trifonov did the next best thing: ask "which terms in the definitions are the most frequent and, thus, perhaps, [reflect] the most important points."
So, he surveyed all of the definitions, grouping the most common non-connective words at least three letters long by their shared meanings. He found that definitions of life most commonly referred to a system, matter, chemistry, complexity, reproduction, evolution, the environment, energy, and ability.
"Thus, the consensus... patched from these nine definientia would be: Life is [System, Matter, Chemical (Metabolism), Complexity (Information), (Self-)Reproduction, Evolution (Change), Environment, Energy, Ability,...] where the square brackets correspond to some compact expression containing the words listed within," he wrote.
In this framework, a potential definition might be:
"Life is metabolizing material informational system with ability of self-reproduction with changes (evolution), which requires energy and suitable environment."
But Trifonov desired a definition that was much more succinct, and so he distilled the nine aforementioned categories down to just two: self-reproduction and changes (evolution). Finally, he arrived at a "definition of life based on... the vocabulary of definitions, and consistent with Darwin’s views":
"Life is self-reproduction with variations."
Trifonov recognized that this definition is quite broad, but noted that it makes room for future forms of life that we might one day discover.
"It can be considered as applicable not just to 'earthly' life but to any forms of life imagination may offer, like extraterrestrial life, alternative chemistry forms, computer models, and abstract forms. "