Sarah Waker & Lee Cronin on Assembly Theory (and a definition of life)
Assembly theory makes the seemingly uncontroversial assumption that complex objects arise from combining many simpler objects. The theory says it’s possible to objectively measure an object’s complexity by considering how it got made. That’s done by calculating the minimum number of steps needed to make the object from its ingredients, which is quantified as the assembly index (AI).
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[Lee Cronin and Sarah Walker] proposed a very general way to identify molecules made by living systems — even those using unfamiliar chemistries. Their method, they said, simply assumes that alien life forms will produce molecules with a chemical complexity similar to that of life on Earth.
https://www.quantamagazine.org/a-new-theory-for-the-assembly-of-life-in-the-universe-20230504/
Complex (technological) objects do not just appear spontaneously in the universe, despite popular folklore to the contrary. Cells, dogs, trees, computers, you and I all require evolution and selection along a lineage to generate the information necessary to exist.
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Attempts to define life have so far failed because they focus on containing the concept of life in terms of individuals rather than evolutionary lineages.
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We need to get past our binary categorization of all things as either “life” or “not.” We should not exclude examples based on naive assumptions about what life is before we develop an understanding of the deeper structure underlying the phenomena we colloquially call “life.”
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Biological beings alive today are part of a lineage of information that can be traced backward in time through genomes to the earliest life. But evolution produced information that is not just genomic. Evolution produced everything around us, including things not traditionally considered “life.” Human technology would not exist without humans, so it is therefore part of the same ancient lineage of information that emerged with the origin of life.
Technology, like biology, does not exist in the absence of evolution. Technology is not artificially replacing life — it is life.
It is important to separate what is meant by “life” here as distinct from “alive.” By “life,” I mean all objects that can only be produced in our universe through a process of evolution and selection. Being “alive,” by contrast, is the active implementation of the dynamics of evolution and selection. Some objects — like a dead cat — are representative of “life” (because they only emerge in the universe through evolution) but not themselves “alive.
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The canonical definition of technology is the application of scientific knowledge for practical use. […] Technology relies on scientific knowledge, but scientific knowledge is itself information that emerged in our biosphere. It enables things to be possible that would not be without it.
Consider satellites. Launching them into space would not have been possible on our planet without Newton’s invention of the laws of gravitation. Newton himself could not have invented those laws if, centuries earlier, humanity had not come to understand the mathematics of geometry or constructed timekeeping devices that allowed us to track seconds. And of course, none of this could have happened if our biosphere had not evolved organisms capable of making abstractions like these in the first place.
Once the knowledge of laws of gravitation became encoded in our biosphere, new technologies were made possible, including satellites. Satellites are not launched from dead worlds or worlds with only microbial life. They require a longer evolutionary trajectory of information acquisition. You can trace that lineage within the history of our species, but arguably it should be traced all the way back to the origin of life on Earth.
Technology, in the broadest sense, is the application of knowledge (information selected over time) that allows things to be possible that are not possible in the absence of that knowledge. In effect, technologies emerge from what has been selected to exist. They are also what selects among possible futures — and builds them.
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We are accustomed to thinking about technology as uniquely human, but in this broader definition, there are many examples across the biological realm. Just like the objects of life might include pencils and satellites, so too technology might include wings and DNA translation.
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People might want to differentiate between biological evolution and the intentionality of humans when we build technologies. After all, software developers and companies choose to produce technology in a different way than ravens evolved wings to fly. But both fundamentally rely on the same principles of selection.
Arguably, the kind of selection humans do is much more efficient than natural selection on biological populations. It is more directed, which is only possible because we ourselves already are structures built across billions of years. We are bundles of possibilities refined by evolution and embodying the history of how we came to exist. The physics governing how we select what we create may be no different (other than by degree of directedness) than how we were selected by evolution. We are, after all, a manifestation of the very physics that allowed us to come to be.
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The technologies we are and that we produce are part of the same ancient strand of information propagating through and structuring matter on our planet. This structure of information across time emerged with the origin of life on Earth. We are lineages, not individuals.
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A natural extension of this evolutionary history is to recognize how “thinking” technologies may represent the next major transition in the planetary evolution of life on Earth.
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What is emerging now on Earth is planetary-scale, multisocietal life with a new brain-like functionality capable of integrating many of the technologies we have been constructing as a species over millennia. It is hard for us to see this because it is ahead of us in evolutionary time, not behind us, and therefore is a structure much larger in time than we are. Furthermore, it is hard to see because we are accustomed to viewing life on the scale of a human lifespan, not in terms of the trajectory of a planet.
Life on this planet is very deeply embedded in time, and we as individuals are temporary instances of bundles of informational lineages. We are deeply human (going back 3.8 billion years to get here), and this is a critically important moment in the history of our planet but it is not the pinnacle of evolution. What our planet can generate may just be getting started. In all likelihood, we are already a few rungs down in the hierarchy of informational systems that might be considered “alive” on this planet right now.
We are 3.8-billion-year-old lineages of information structuring matter on our planet.
https://www.noemamag.com/ai-is-life/
Quote sarah walker lee cronin physics evolution chemistry life