From: jimruttshow8596
The origin of life is a recurring theme in scientific discussions, and Assembly Theory offers a novel framework for understanding this fundamental transition [37:58:00]. Instead of focusing solely on chemical phenomena leading to a replicating molecule or autocatalytic set, Assembly Theory addresses the origin of life as a continuous, recursive transformation, or “cascade,” that has been building complexity on Earth for four billion years and continues to this day [38:56:00].
Assembly Theory’s Approach to Life’s Origins
Assembly Theory proposes a definition of complexity based on the minimum number of steps required to build an object, known as its “assembly index,” and the number of identical copies of that object [14:52:00]. This approach aims to distinguish between objects formed by chance and those that have undergone selection [15:10:10]. A key insight is that the theory was developed with measurability in mind, enabling experimental validation in a lab setting [26:56:00].
The Abiotic-Biotic Transition
Assembly Theory identifies a “sharp phase transition” between non-biotic (inorganic) and biotic chemistry [40:56:00]. While there is a continuum of complexity, life appears to act as an amplifier, rapidly increasing complexity and creating a clear gap in the combinatorial space between non-life and life [42:01:00]. Life can produce low assembly items, but the observation of high assembly objects (e.g., above 14-15 steps in chemical complexity) is considered a definitive signature that “living physics” is present [43:30:00]. This threshold exists because making objects in an exponentially expanding combinatorial space requires selection, otherwise, there’s no a priori expectation they would be produced [44:06:00].
Selection and Memory in Prebiotic Systems
A crucial aspect of Assembly Theory is the idea that selection must predate biology as we know it [36:52:00]. Without selection occurring before biology, the emergence of complexity would require a “local creationist” or a “miracle” [36:59:00]. Assembly Theory proposes a mechanism where selection initially builds things randomly, and then, by chance, the universe builds mechanisms for memory [37:09:00].
Memory, such as the deep memory in DNA and the local memory in cellular metabolism, is seen as a prerequisite for creating large organic molecules [32:26:00]. This implies that as structures allowing memory to become deeper and more complicated evolved in the universe, the ability to take more assembly steps increased [33:43:00]. Assembly Theory suggests that life is a “stack of objects” deeply embedded in time, recursively assembling other objects, and this entire stack is necessary to achieve high assembly levels [44:40:00]. The theory effectively “kills Einstein’s block Universe” by asserting that some things must happen before others, which is fundamentally incompatible with the block universe view [01:02:01].
Experimental Proof and Future Directions
The ultimate experimental proof for solving the origin of life problem, according to Assembly Theory, would be evolving “alien life” from scratch in the lab [40:01:00]. This would demonstrate a totally de novo origin of life event, exploring different regions of chemical space, rather than merely recapitulating steps thought to have occurred on early Earth [40:07:00]. Researchers are actively working on experiments to force systems to cross the assembly threshold characteristic of life [01:19:17].
Implications for Extraterrestrial Life
Assembly Theory has significant implications for the search for extraterrestrial intelligence (SETI) and the Fermi Paradox [01:07:07]. It suggests that the Fermi Paradox might be a “great perceptual filter,” meaning humanity hasn’t yet developed the “perceptual apparatus” or physics to recognize life beyond Earth [01:08:27]. Just as gravitational waves permeated the planet for billions of years before their detection was made possible by Einstein’s theory and subsequent technological development, alien life or “technosignatures” might be currently undetectable due to a lack of understanding of the fundamental physics of life [01:09:03].
The theory suggests that alien life would follow a “completely different trajectory” through chemical space, making it difficult to recognize due to a lack of “overlapping histories” or shared information [01:13:15]. However, Assembly Theory could potentially provide a “Rosetta Stone” for understanding complexity across different domains [01:12:06]. By modeling planetary atmospheres and evolution using assembly theoretic principles, scientists aim to detect the “memory” of a planet’s past states and the “structure of evolving complexity” remotely, potentially using telescopes like the James Webb Space Telescope [01:14:11].
Regarding the probability of life evolving on a suitable planet (as in the Drake equation), Assembly Theory posits that statements cannot be made until the problem of life’s origin is solved [01:19:51]. The entire causal chain of life on Earth is seen as a unique structure, where every event is improbable [01:18:50]. However, the omnipresence of selection in the universe might imply that life, as a persistent drive towards complexity, is common, requiring a re-framing of the question to focus on “how much selection is required to get that transition” [01:21:19]. Assembly Theory suggests that selection is as fundamental for the emergence of life as gravity is for the emergence of stars [01:22:38].