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Origin-of-Life Research: Start Over


Hardly a month goes by without a celebration in the news that the “building blocks of life” have been found somewhere in space, or that chemical reactions “show how life emerged” on the primitive earth. Recently, the University of Bern triumphantly announced that “Rosetta’s comet contains ingredients for life.” All that was detected was glycine (the simplest and the only achiral amino acid) and the element phosphorus (which is tantamount to calling any other element, like hydrogen or oxygen, an “ingredient for life”). New Scientist chimed in: “Building blocks of life spotted around comet for the first time.” Meanwhile, PhysOrg suggested there might be life on the asteroid Ceres. Why? Because water ice probably exists under the surface.

The mainstream media typically report such findings uncritically. It’s refreshing, then, to see a chemist and a space scientist take a hard look at the failings in origin-of-life research. In America’s leading journal, Science, they ignore the hype about water and simple chemicals implying life. They “get real” about the limits of chemistry. And they seriously look for radically different ways to approach the problem — some of which will be of interest to design theorists.

One of the authors is Leroy Cronin, a chemist at the University of Glasgow (where, incidentally, Darwin critic William Thomson — Lord Kelvin — had his long and distinguished career). The other is Sara Imari Walker from Arizona State where space science is big and aggressive atheist cosmologist Lawrence Krauss is a campus celebrity; she’s also a member of the Blue Marble Space Institute for Science here in Seattle.

They have no patience with the usual celebratory fluff. They want a revolution:

How can matter transition from the nonliving to the living state? The answer is essential for understanding the origin of life on Earth and for identifying promising targets in the search for life on other planets. Most studies have focused on the likely chemistry of RNA, protein, lipid, or metabolic “worlds” and autocatalytic sets, including attempts to make life in the lab. But these efforts may be too narrowly focused on the biochemistry of life as we know it today. A radical rethink is necessary, one that explores not just plausible chemical scenarios but also new physical processes and driving forces. Such investigations could lead to a physical understanding not only of the origin of life but also of life itself, as well as to new tools for designing artificial biology. [Emphasis added]

In one fell swoop, Cronin and Walker have cast doubt on essentially the whole history of origin-of-life research. Whether from Oparin, Miller, Orgel, Benner, Hud, Russell, Cairns-Smith, Wachtershauser, Shapiro, or maybe even “warm little pond” Darwin himself — it’s all inadequate and probably misguided. Otherwise, why would a “radical rethink” be necessary?

Here’s what most of the previous work has been “narrowly focused” on: chemical reactions. From Stanley Miller’s 1953 lightning flask to the present, almost all the work has assumed that if you can get some molecules that life uses, you’re making progress to understanding life’s emergence. One can speculate about a “scenario” where these chemicals would fit into a grand story of life’s emergence.

Such thinking is flawed for a number of reasons, some of which we can glean from the paper and summarize here:

  • Dilution and entropy: “Left unattended, sophisticated chemistry becomes more dilute and disordered.”

  • Oversimplification: “A quick route to complexity and enrichment that could lead to the development of evolvable units seems to be required to avoid this serious issue.”

  • Ends without means: “Yet, most research efforts have focused on detailing precise chemical mechanisms for producing high yields of individual bio-inspired products, without addressing the processes necessary to form increasingly complex molecules and networks.”

  • Improbability: “The molecular constituents of simple networks are more likely to arise by chance than the highly evolved molecules of extant life.”

  • Begging the question: “how did evolution begin if the complex machinery for evolution was not in place?”

Indeed, their last paragraph shows they are ready to sweep the field clean and start over:

Progress will be made by challenging all historical prerequisites assumed to be important in the origin of life. We should aim to develop measurable and collaborative routes to explore the physics and chemistry of life’s origins and the living state. Not only is a comprehensive understanding of what it means for a physical system to be alive required but also a new multidisciplinary, multinational project to generate new life in the lab or in silico, to search for life on Earth that uses an alternative chemistry to that found in biology, and to explore the potential for life on other worlds. For this to be possible, researchers must challenge the current models and historical approach and be willing to work together across disciplinary boundaries to see if a process-based model can be used to understand and control the transition from inorganic matter to biology.

Having dismissed the obsession with “plausible chemical scenarios,” what do Cronin and Walker advise for their radical rethink? What should origin-of-life research focus on instead? Here it is — (drumroll) — information. We’ll understand life, they say, when we look at how information flows in networks.

What happens to our traditional perspectives if we do not restrict attention to the chemical substrates of known life? The development of networks over time may be more important than the specific chemical nature of their molecular components….

A concept of information relevant to biological organization may be essential to identifying these networked processes. Adami and LaBar have described life at a basic level as “information that copies itself”. Given that life not only copies information but also uses information to construct itself, we might instead describe the start of life as “simple machines that can construct slightly more complicated machines.” Focusing on information in this way moves the narrative even further from a chemistry-specific mode than focusing on networks alone but may perhaps provide our best shot at uncovering universal laws of life that work not just for biological systems with known chemistry but also for putative artificial and alien life. For example, Walker et al. have recently shown that information-theoretic measures distinguish biological networks from random ones, even in cases where the biological networks share important network properties (such as topological features) with random networks. Life requires chemistry, but the properties of the living state emerge from the dynamical properties of that chemistry, including the temporal and spatial organization of molecular networks and their information management.

Well, Chris Adami of Avida fame has tossed out one point of agreement on which to advance the discussion: information must be central to discussions of life. But doesn’t information presuppose sentient agents, or systems designed by sentient agents? Otherwise, how do they recognize and respond to information? How can they perform “information management”? A falling rock that triggers an avalanche can hardly be thought of as managing information in a network. In our uniform experience, machines and networks that share information have been intelligently designed (read Dembski’s book Being as Communion for a detailed exposition of the concept of information).

So close, yet so far away. Cronin and Walker immediately return to a chemistry focus of their own, trying to compare the emergence of life to a “phase transition,” using one of the origin-of-life field’s favorite magic words, emergence, a dozen times.

One appreciates their call to scientific rigor: “speculation should be restricted to the development of experimentally testable hypotheses that address key questions and provide a focus for progress.” And one appreciates their insertion of the design-rich terms machinery, information, and networks in the discussion. Unfortunately, their own “radical rethink” relies on the same materialistic assumptions that have stifled and baffled researchers since Darwin.

Photo: Surface of Rosetta’s comet, by ESA/Rosetta/NAVCAM, CC BY-SA IGO 3.0 [CC BY-SA 3.0-igo], via Wikimedia Commons.