Is Life Just Chemistry, or Chemistry Plus Information?
In 2016, University of Ferrara theoretical biologist Marcello Barbieri wrote a rather interesting open access paper on a key philosophical conflict in biology: Is life only chemistry or is it chemistry plus information? In it, he says that many biologists see information in life forms — biological information — as something that “does not really belong to science.”
How did they get there from here?
Author of Code Biology: A New Science of Life (Springer, 2015), Barbieri offers a history, a critique, and a proposed solution. In this and two upcoming articles, I will look at all three elements.
First, the History
Molecular biology understands genes as transferring linear sequences of information to proteins that carry out instructions. That’s information as it is generally understood. But some biologists, surveying the vast, complex, specified structures it builds, appear spooked by the thought:
This implies that there is an ontological difference between information and chemistry, a difference which is often expressed by saying that information-based processes like heredity and natural selection simply do not exist in the world of chemistry. Against this conclusion, the supporters of the chemical paradigm have argued that the concept of information is only a linguistic metaphor, a word that summarizes the result of countless underlying chemical reactions. The supporters of the information paradigm insist that information is a real and fundamental component of the living world, but have not been able to prove this point. As a result, the chemical view has not been abandoned and the two paradigms both coexist today.
BARBIERI MARCELLO 2016 WHAT IS INFORMATION? PHIL. TRANS. R. SOC. A.3742015006020150060 HTTP://DOI.ORG/10.1098/RSTA.2015.0060, 13 MARCH 2016
Barbieri offers a solution, which we will look at later. But for now, note the nature of the conflict: “Information can’t be real if chemistry doesn’t completely subsume it” versus “information is real, apart from chemistry.”
He points to origin of life researcher Günter Wächtershäuser as a leading exponent of the first view: “If we could ever trace the historic process backwards far enough in time, we would wind up with an origin of life in purely chemical processes.” The physicalism that Wächtershäuser espouses here may cause us to overlook the fact that we really have no idea how to trace the “historic process” that far back in time. His claim is simple but not easily researchable. And in these times, that fact alone gives his chemical paradigm a certain weight. A dominant idea that cannot be proved can also not be disproved.
Of course, as Barbieri notes, Watson and Crick’s discovery of the double helix suggested the image of life forms as “information-processing machines.” That image was not welcomed in many places:
This is one of the most deeply dividing issues of modern science. Many biologists are convinced that biological information and the genetic code are real and fundamental components of life, but physicalists insist that they are real only in a very superficial sense and that there is nothing fundamental about them because they must be reducible, in principle, to physical quantities.
BARBIERI MARCELLO 2016 WHAT IS INFORMATION? PHIL. TRANS. R. SOC. A.3742015006020150060
HTTP://DOI.ORG/10.1098/RSTA.2015.0060, 13 MARCH 2016
He realizes that conventional biologists’ most serious intellectual commitment is to Darwin’s theory of evolution by natural selection acting on random mutation — a commitment he appears to support. So he reassures readers that Wächtershäuser’s “life is just chemistry” approach doesn’t really accord with Darwinism after all because “natural selection, the cornerstone of Darwinian evolution, does not exist in inanimate matter.” He does not seem to grasp that the two theories get on very well precisely because both purport to explain how bewilderingly complex and highly specific life forms can come to exist in a universe that is devoid of intelligence.
So What Type of Material Substance Is Information?
The problem he does not address is that information, unlike chemistry, is fundamentally immaterial. A USB stick that contains vital information weighs the same as one that contains nothing or strings of random numbers. And the content, meaningful or not, is measured using concepts like bits and bytes, not physical attributes like kilograms and joules. And, unlike other quantities, information can convey meaning.
Meaning is a term Barbieri uses a good deal:
The existence of meaning in the organic world may seem strange, at first, but in reality it is no more strange than the existence of a code, because they are the two sides of the same coin. To say that a code establishes a correspondence between two entities is equivalent to saying that one entity is the meaning of the other, so we cannot have codes without meaning or meaning without codes. All we need to keep in mind is that meaning is a mental entity when the code is between mental objects, but it is an organic entity when the code is between organic molecules.
BARBIERI MARCELLO 2016 WHAT IS INFORMATION? PHIL. TRANS. R. SOC. A.3742015006020150060
HTTP://DOI.ORG/10.1098/RSTA.2015.0060, 13 MARCH 2016
No, actually. Meaning is an aspect of conveying information to an intelligent being, as in “The meaning of James’s earlier actions became clear to us when he suddenly switched sides.” If anything in life forms has a meaning, an intelligent agent will be needed to recognize it.
And if the chemistry-only faction is at all consistent, it should have no truck whatever with the idea that “meaning is a mental entity when the code is between mental objects.” True physicalism denies that there are any mental objects. The mind is an illusion generated in the brain via natural selection, one that happens to further human survival. Meaning is merely a part of that illusion.
Barbieri seems to want biology to combine physicalism with an acceptance of information — information that is stripped of its relationship to intelligence and thus somehow belongs to science after all. But, as we shall see, it can’t be done.
Next: Can information be separated from intelligence? Barbieri tries for an origin of life theory that allows for information but tries to separate it from intelligence. Does he succeed? I will consider that question in a subsequent post.
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