If Microbes begat Mind – Debates

DEBATES ABOUT DEFINING LIFE

The greatest barrier to proving how the origin of life occurred lies in the debates about how to define life. Trying to define life raises questions about proof and disproof. The chart below highlights the primary arguments for how to define life.

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DEBATES ABOUT THE ORIGIN OF LIFE

The debates about whether replication or enclosure or metabolism came first in the origin of life overlook a logical fallacy. First life might have accidentally replicated (although life couldn’t logically “replicate” until there was life to replicate) or accidentally recruited “the right stuff” into its enclosure (although keeping that right stuff may also have entailed recognition of what to retain and what to filter out). But in order for life to metabolize, life had to recognize what to metabolize.No one questions that when humans discover or invent, someone must recognize possibility. Although Columbus didn’t recognize that he’d discovered America, others did. A capacity we associate with consciousness — mind — seems in rudimentary form to have been present at the dawn of life and to have been a defining prerequisite for life to live and evolve.

The A-PR Hypothesis (Autonomy | Pattern Recognition) addresses three debates about the origin of life, proposing that the threshold when the origin of life occurred should be defined as the moment when data processing began. Contradictions in debated hypotheses about whether replication, enclosure, or metabolism came first in the origin of life stem from a materialist definitions of the origin of life. All three hypotheses assume capacity for pattern recognition, which implies executing A-PR cycles.

1. Did replication or metabolism come first?
2MbM-debatesTwo competing hypotheses focus on whether replication (transmitting information) or metabolism (processing energy) came first. Freeman Dyson assumed that there must be a logical way to dissolve the either-or debate as to whether replication or metabolism came first in the origin of life. Could metabolic life exist without replication? Or replicative life without metabolism? How could either come first, without the other? Dyson sought a higher order synthesis by asking whether either replication or metabolism could function independently. His either/ or skepticism prompted his Double Origin Hypothesis for the origin of life, that these two life functions must have been invented separately (Dyson 1982, 1985). Dyson’s Double Origin Hypothesis raises a question: What do we take for granted when we ask whether replication or metabolism came first, or whether they occurred together in a double origin? Suppose that neither came first, that both share a single prerequisite, that pattern recognition is required to select the raw material to convert into energy for life, which must have preceded metabolism. Recognizing and tapping an energy source is a prerequisite to live, the first step toward harnessing energy to perform work. The replication versus metabolism debate dissolves when we seek the foundation that enables replication and metabolism to occur — A-PR cycles, Autonomy and Pattern Recognition. The A-PR Hypothesis postulates that life’s autonomy and capacity for pattern recognition came first as defining attributes of life, characterizing the threshold when non-life came to life.

2. How was a self-other distinction critical for life’s origin?

Beyond the two-headed Janus of a Double Origin, the third debated hypothesis concerns life’s identity: How did life distinguish its “self” from “other,” which was not alive? One school of theorists focuses on the role of enclosure in the origin of life, positing as a possible first step that life formed a vesicle to distinguish its “self” from “other,” enabling proto-life to emerge and self-organize as it defined itself (Deamer et al. 1982; 2010). After analyzing the Murchison meteorite, Deamer united the macro context of interstellar space with laboratory synthesis of vesicles to observe how in aqueous environments, amphiphiles self-assemble into stable lipid bilayers, probable precursors for membranes that self-organize into vesicles when exposed to liquid water. Deamer wondered why life designs its boundary structures as lipid bilayers built of amphiphiles, molecules with heads attracted to water (hydrophilic) and tails repelled by water (hydrophobic and lipophilic, or oil-loving).

Deamer sees membranes as critical boundaries between life’s self and other, enabling life to originate and design itself. Within these membranes, vesicles concentrate life’s ingredients. Gradually these bounded collections of constituents organize themselves collaboratively to come to life. Through self-assembly of hydro-carbon derivatives into structures with semi-permeable membranes, life’s precursors set the stage for the origin of life, the capacity to tap an energy source (Deamer 1982, 2010). Focus on the enclosure-first theory of the origin life, and the role of membranes in distinguishing self from other, raises a question: How does a living organism “select” what to admit into its enclosure or exclude, what to adapt into “self” (food) and what to filter out, as “other” (waste)? To filter food from waste requires that living organisms have autonomy and capacity for pattern recognition (Gill 2011b). Purely physical principles could mediate a coordinated interaction between genome and compartment boundary, independent of any genomic functions beyond self-replication. If so, then osmotically driven, competitive vesicle growth could have played a key role in the emergence of Darwinian evolution (Chen et al. 2004).

3. A-PR cycles, prerequisites for replication, metabolism and enclosure

Debates about whether replication, metabolism, or enclosure came first in the origin of life all point to the A-PR hypothesis as a precursor. The replication first argument states that life originated with the first successful mutational replication. However, life couldn’t logically “replicate” unless there was already life to replicate. To replicate, a protocell needs energy. To benefit from random mutations, life must have a mechanism to recognize which mutations fall within an acceptable tolerance range in order to assimilate useful mutations into its evolving system. To metabolize, life had to recognize what to metabolize, to discriminate between edible and non-edible stuff. The enclosure first argument, that life accidentally recruited “the right stuff” into its enclosure, overlooks that to select what to admit into its enclosure as possible to adapt into itself, life needed capacity for pattern recognition. To keep that right stuff, life had to recognize what to retain and what to filter out (Gill 2011c).

ZannGill-A-PRdiag-BEST2-bw-8-12

Figure. The A-PR Hypothesis posits that autonomy and pattern recognition are life’e most basic attributes — prerequisites for replication, metabolism, and enclosure.

Logically then, life’s most basic capacity, pattern recognition, would have enabled replication, metabolism and enclosure to function on behalf of the living organism and would have defined the moment when non-life came to life. To originate life, and to resolve debates about the origin of life, requires agency – Autonomy, guided by capacity for Pattern Recognition.

“I think, therefore I am” versus “I am, therefore I think”

René Descartes focused on analysis, maintaining that rational thinking must start from certain bedrock. He built his “logic of deduction” on the foundation of facts that we can know with certainty. Deduction allows the mind to move step-by-step from one idea to the next, tracing a path of inference from premises to a conclusion. With “cogito ergo sum” [I think; therefore I am], Descartes saw the point of departure for a rationalist philosophy. But this hard rock of certainty was based on his subjective perception. I think, therefore. . .

Philosopher Martin Heidegger also sought a bedrock foundation, but he disagreed with Descartes as to what was bedrock. Reversing Descartes’ criterion for rational thinking to “I am; therefore I think” led Martin Heidegger to propose that “Being” was bedrock. Existence sounds reasonably basic, but only in an object world. The nexus between thinking and being alive, both processes, will be broken if computers develop the capacity to think. If they can think, will we call them alive?

Descartes, the father of rationalism, described intuition, as “not the wavering assurance of the senses, or the deceitful judgment of a misconstructing imagination, but a conception, formed by unclouded mental attention, so easy and distinct as to leave no room for doubt in regard to the thing we are understanding. It comes to the same thing if we say: It is an indubitable conception formed by an unclouded mental attention, one that originates solely from the light of reason, and is more certain even than deduction, because it is simpler.” So Descartes, the rationalist, opened a window through which C.S. Peirce saw the need for “abduction” (beyond induction and deduction, thinking horizontally, by analogy) and made that leap.

One might assume that Descartes’ and Heidegger’s two statements exhaust our options. But there’s a third option. What intrigues me about both statements is neither “thinking” nor “being” as their starting points, but rather the criterion for making either statement in the first place — the assumption of both that the bedrock of certainty should be the starting point.

Rather than reverse Descartes’ statement, as Heidegger did, I propose reversing the criterion that generated both statements. Descartes started from that of which he was most certain. So did Heidegger. Both of these thinkers perceived a need to start from certainty, although they disagreed about what was certain.

I disagree with their criteria for defining where to start. Suppose problem-solving starts from the place of maximum uncertainty — neutral gray on the spectrum between black and white, where maybe. . . there might be an image of a zebra.

Questioning the “Cartesian dictum” counters Descartes’ idealized view, and the conventional view in science for several hundred years, that a scientist must start from certainty. “Reversing the Cartesian dictum,” I propose starting from the gray neutrality from which figure emerges, from uncertainty, to gradually bring its subject into focus.

Shifting focus from object to process, from analysis of objects to their design, requires recognizing the potential in starting from uncertainty.

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Overview of the Book
Reviewer comments on the book, pre-release
Quotes from the book