This post is a concluding one on the topic: ‘the equation for intelligence’ — F = T ∇ Sτ. I have noticed that whenever I try to explain it at any social occasion there is either a glazed over look in the eyes of the listener or a furtive check of their smartphones for a nonexistent recent text message. Understandably most people read the news or browse the blogs to confirm their preconceptions of their world view (aided by being in a Google bubble). Rarely are they willing to undergo any questioning or change in their status quo. I think that by the age of about 25 you’ve formed a world view and you may make small changes as you go along but almost never make a paradigm shift.
It is in this context that ‘the equation for intelligence’ appeals to me. Having a Taoist predisposition to seeing the universe as self-organising and naturally flowing along intelligence lines, the universal law of intelligence proposed by Wissner-Gross seemed imminently sensible. Having spent more than 40 years as a molecular virologist I have marvelled as to how fundamental life processes follow this knife-edge path between chaos (disorder) and stability (stagnation). One of my favourite examples of this is the life cycle of a simple bacterial virus MS2. For the purposes of the story-telling I shall simplify some details but hopefully preserve the elegance of the life-cycle.
MS2 Phage Life-Cycle
The host of this virus is the common E.coli bacteria found in vast quantities in your gut (and faeces). MS2 is one of simplest viruses consisting of 180 molecules of a coat protein, one copy of a maturation protein and an single-stranded RNA molecule consisting of 3569 nucleotides. The virus forms an icosahedral shell with the RNA inside, (see the right-handed side of the diagram above). This RNA codes for four proteins — the maturation (A-protein), the coat protein (CP), a lysis protein (which overlaps the coat protein) and the replicase protein (RdRp) for making RNA copies (see gene order and diagram below). The expression of these genes - their timing and the quantities produced is orchestrated in the most elegant way. The reading of genes on an RNA molecule by ribosomes and the protein translating system occurs from left to right (this true of all messenger RNA’s including our own).
When the viral RNA molecule enters the bacteria the first gene is the maturation gene (protein-A) which would normally be the first gene expressed by the ribosomes but its 5’-end is hidden within a RNA secondary structure so the first gene to be read is the coat protein which makes sense since the virus needs 180 copies. The start of the maturation protein gene is only accessible in RNA freshly replicated (before it can fold on itself) — only a few copies are made per RNA (only one copy is actually required). As the ribosomes travel along the RNA, the gene downstream to the coat protein is the replicase gene — this enzyme is necessary to make RNA copies but only a few copies are necessary since one replicase enzyme molecule can make hundreds of RNA copies. To shutdown this gene dimers of the coat protein bind to the start of the replicase gene and block further ribosomes from binding — shutting down the making of more copies of replicase.
Copies of the coat protein continue to be made — 180 are required per virus particle. Finally the lysis protein is expressed and this is controlled by ‘slip back’ by the ribosomes to the start of the lysis protein gene within the coat protein gene (the gene within a gene). Ribosomes as they travel along the RNA are ‘noisy’ and can fall off or slip —particularly at a slippery part of the RNA near the start of the lysis gene at about a 5% frequency. This ensures that lysis expression occurs late in the life cycle (you don’t want cells bursting open before sufficient virus accumulates). The lysis protein forms pores in the cell wall of the host and the bacteria breaks open releasing hundreds of progeny virus particles that can infect more bacteria.
The key points of this story were to illustrate the elegant self-organising mechanisms that regulate the interplay between gene expression and RNA secondary structure and that the expression of the lysis gene depended on noisy ribosomes (entropic increase in the possible futures) to complete the life cycle of the virus. An example of “intelligence acting to maximise the future freedom of action — F = T ∇ Sτ ”. Or from a Taoist point of view the life-cycle follows the Tao "the path" or "the way” — the universal principle that underlies everything from the creation of galaxies to the interaction of human beings.