The Origin of Life: Complexity, Thermodynamics, and Memory

In our quest to understand the universe, perhaps no question is as profound and captivating as the origin of life. How did non-living matter transition into the intricate, self-replicating, and evolving entities we call life? This blog post delves into the fascinating perspective of Terrence Deacon, a renowned scholar whose work intersects anthropology, neuroscience, and evolutionary biology. Deacon offers a unique lens through which to view the origin of life, emphasizing the crucial roles of complexity, thermodynamics, and memory. These concepts, when interwoven, provide a compelling narrative about how life may have emerged from the non-living world.

This discussion complements our recent podcast episode, Terrence Deacon & Michael Levin: What is Life? Complexity, Cognition & the Origin of Purpose, where we explored these ideas in depth with both Terrence Deacon and Michael Levin. In that episode, we covered a range of topics from Daniel Dennett’s work to the nuances of teleonomy and preformationism. This blog post offers a deeper dive into Deacon's specific viewpoint on the origin of life, providing further context and expanding upon the concepts discussed in the episode.

Terrence Deacon's Perspective: Complexity, Thermodynamics, and Memory

Terrence Deacon's approach to understanding the origin of life is rooted in the idea that life is not simply a complex chemical reaction but a fundamentally different kind of process. He argues that traditional views often overlook the unique characteristics that distinguish living systems from non-living ones. For Deacon, complexity, thermodynamics, and memory are not merely contributing factors but essential and interconnected components that define life's emergence.

Deacon proposes that life arises from a specific type of self-organizing system, one that is not just complex but also inherently teleological, meaning it exhibits a form of "aboutness" or intentionality. This teleological aspect is not pre-programmed but emerges from the system's unique thermodynamic properties and its ability to maintain a form of "memory" or historical contingency.

The Role of Complexity in the Origin of Life

Complexity is often cited as a defining characteristic of life. Living organisms are undeniably intricate systems composed of countless interacting components. However, Deacon argues that complexity alone is insufficient to explain the origin of life. A crystal, for example, can exhibit a high degree of structural complexity, but it lacks the dynamic, self-maintaining, and evolving properties that characterize life.

For Deacon, the relevant type of complexity is a specific kind of organizational complexity – one that involves hierarchical levels of control and constraint. This type of complexity allows for the emergence of novel properties and behaviors that are not present in the individual components themselves. In the context of the origin of life, this means that the first living systems were not merely collections of complex molecules but organized systems with emergent properties such as self-replication and metabolism.

Furthermore, this organizational complexity is not static but dynamic, constantly adapting and evolving in response to environmental changes. This adaptability is crucial for survival and is a key feature that distinguishes living systems from non-living ones. The emergence of this dynamic organizational complexity is, according to Deacon, intimately linked to the system's thermodynamic properties and its ability to "remember" past states.

Thermodynamics and Life's Emergence

Thermodynamics, the study of energy and its transformations, plays a central role in Deacon's perspective on the origin of life. He argues that living systems are not simply driven by the laws of thermodynamics but actively harness and exploit these laws to maintain their organization and function. Specifically, he focuses on the concept of "dissipative structures," which are systems that maintain their organization by dissipating energy.

Dissipative structures are characterized by their ability to create and maintain order in an environment that is otherwise tending towards disorder (entropy). Living organisms are prime examples of dissipative structures, constantly consuming energy to maintain their internal organization and repair damage. This requires a continuous flow of energy and materials, which is why living systems are inherently coupled to their environment.

Deacon argues that the origin of life may have involved the emergence of self-organizing dissipative structures that were able to harness energy from the environment and use it to maintain their own complexity. These early protocells would have been able to extract energy from chemical gradients or other sources and use it to drive the processes necessary for self-replication and metabolism. The key is that these processes were not simply driven by random chemical reactions but were actively regulated and controlled by the system's internal organization.

The significance of this thermodynamic perspective is that it provides a framework for understanding how life can emerge from non-life without violating the laws of physics. Life is not a violation of the second law of thermodynamics but rather a clever exploitation of it. By dissipating energy, living systems are able to create and maintain order, albeit at the cost of increasing entropy in their surroundings.

Memory as a Key Component

While complexity and thermodynamics are crucial for understanding the origin of life, Deacon argues that memory is the missing piece of the puzzle. He defines memory not simply as the storage of information but as the ability of a system to be influenced by its past states. This historical contingency is essential for understanding how living systems evolve and adapt.

In the context of the origin of life, memory refers to the ability of early protocells to "remember" which configurations were successful and which were not. This could involve the selective amplification of certain chemical reactions or the preferential incorporation of certain molecules into the protocell's structure. Over time, this process of selective reinforcement would lead to the evolution of more efficient and stable protocells.

Deacon emphasizes that this type of memory is not necessarily encoded in genes or other explicit information storage systems. It can also be embodied in the system's physical structure and chemical composition. For example, the arrangement of molecules in a protocell's membrane could serve as a form of memory, influencing its interactions with the environment and its ability to replicate. This type of embodied memory is particularly important in the early stages of life, before the emergence of sophisticated genetic information storage systems.

The concept of memory also highlights the importance of history and contingency in the origin of life. The specific path that life took to emerge on Earth was not predetermined but rather shaped by a series of chance events and historical circumstances. This means that the origin of life is not simply a matter of finding the right set of chemical reactions but also understanding the historical context in which those reactions occurred.

Contrasting Perspectives: Deacon vs. Levin

In the podcast episode, Terrence Deacon's perspective is juxtaposed with that of Michael Levin, offering a richer understanding of the complexities surrounding the origin of life. While both scholars are deeply invested in unraveling the mysteries of life's emergence, they approach the problem with slightly different emphases. Levin's work often focuses on the role of information processing and decision-making in biological systems, even at the cellular level. He explores how cells can "compute" and coordinate their behavior to achieve specific goals, such as regenerating damaged tissues or developing into specific organs.

While Deacon emphasizes the thermodynamic and historical constraints that shape life's emergence, Levin tends to focus on the computational and problem-solving abilities of living systems. This difference in emphasis is not necessarily a contradiction but rather a reflection of the different levels of analysis they employ. Deacon is primarily concerned with the fundamental principles that underlie life's emergence from non-life, while Levin is more interested in the specific mechanisms that allow living systems to function and adapt.

These contrasting perspectives provide a more holistic view of the origin of life, highlighting the importance of both thermodynamic constraints and computational abilities. Life is not simply a matter of harnessing energy and maintaining order but also of processing information and making decisions. By considering both of these aspects, we can gain a deeper understanding of the challenges and opportunities that shaped the emergence of life on Earth.

The Self, Beneficiaries & Causal Emergence

A key aspect of Deacon's perspective is the idea of "causal emergence," which refers to the emergence of new causal powers at higher levels of organization. In the context of life, this means that living systems are not simply collections of molecules but entities with their own causal agency. They are able to act on their environment and shape their own destiny in ways that are not possible for non-living systems.

This concept is closely related to the idea of "the self" or "autonomy." Living systems are not simply passive recipients of external forces but active agents that strive to maintain their own integrity and achieve their own goals. This self-directedness is a defining characteristic of life and is essential for understanding how living systems evolve and adapt.

Furthermore, Deacon argues that living systems are inherently "beneficiary-oriented." This means that their actions are ultimately directed towards benefiting themselves, whether that means acquiring resources, avoiding threats, or reproducing. This beneficiary-oriented behavior is not necessarily conscious or intentional but rather a consequence of the system's internal organization and its drive to maintain its own existence.

The emergence of the self, beneficiaries, and causal agency is a crucial step in the transition from non-life to life. It represents a fundamental shift in the nature of causality, from a purely deterministic system to one in which agents can act on their environment and shape their own destiny.

Regeneration & Memory: Decompression Processes & Complexity

The ability to regenerate damaged tissues is a remarkable feature of many living organisms. This ability is closely linked to the concept of memory, as the organism must "remember" its original form in order to regenerate it accurately. Deacon argues that regeneration involves a process of "decompression," in which the organism relaxes constraints and allows its underlying structure to reassert itself.

This decompression process is not simply a matter of reversing the damage but also of actively reconstructing the original form. This requires a complex interplay of chemical signals, cellular interactions, and physical forces. The organism must be able to coordinate these processes in a precise and timely manner in order to ensure that the regenerated tissue is functional and integrated into the rest of the body.

The ability to regenerate is also closely linked to the concept of complexity. The more complex an organism is, the more challenging it is to regenerate it. This is because the organism must be able to coordinate the regeneration of many different types of tissues and organs, each with its own unique structure and function.

The study of regeneration can provide valuable insights into the nature of memory and complexity in living systems. By understanding how organisms are able to regenerate damaged tissues, we can gain a deeper appreciation for the remarkable abilities of life.

Meta-Constraints: Problem Solving Agents & Bioengineering Surprises

Deacon introduces the concept of "meta-constraints," which are constraints that act on other constraints. In the context of life, meta-constraints are the principles that govern how living systems organize themselves and solve problems. These meta-constraints are not simply pre-programmed but rather emerge from the system's interactions with its environment and its own internal dynamics.

One example of a meta-constraint is the principle of "least effort," which states that living systems tend to choose the simplest and most efficient solution to a problem. This principle is not simply a matter of laziness but rather a consequence of the system's drive to conserve energy and resources. By choosing the simplest solution, the organism can minimize its energy expenditure and maximize its chances of survival.

The concept of meta-constraints is particularly relevant to the field of bioengineering. As we attempt to design and build artificial living systems, we must be mindful of the meta-constraints that govern the behavior of natural living systems. If we ignore these meta-constraints, we are likely to encounter unexpected and undesirable outcomes. This can lead to "bioengineering surprises," in which our artificial systems behave in ways that we did not anticipate or intend.

By understanding the meta-constraints that govern living systems, we can improve our ability to design and build artificial life. This can lead to new technologies and applications in fields such as medicine, agriculture, and environmental science.

Conclusion: Reflecting on Life's Beginnings

Terrence Deacon's perspective on the origin of life offers a compelling and nuanced understanding of how non-living matter may have transitioned into the complex, self-replicating, and evolving entities we call life. By emphasizing the crucial roles of complexity, thermodynamics, and memory, Deacon provides a framework for understanding how life can emerge from non-life without violating the laws of physics.

His work challenges traditional views that focus solely on the chemical reactions involved in life and instead highlights the importance of organizational principles, thermodynamic constraints, and historical contingency. By considering these factors, we can gain a deeper appreciation for the remarkable abilities of living systems and the challenges and opportunities that shaped the emergence of life on Earth.

We invite you to listen to the full conversation with Terrence Deacon and Michael Levin in our episode, Terrence Deacon & Michael Levin: What is Life? Complexity, Cognition & the Origin of Purpose, to explore these ideas further and delve into the contrasting perspectives that enrich our understanding of life's beginnings. The insights shared by Deacon and Levin provide a foundation for continued exploration and discovery in the quest to unravel the mysteries of life.