"It" from "Bit"

The understanding of DNA – its famous double helix structure, its 4-letter code (A, T, G, and C) – led to multiple fields of study in biology. Some biologists began to focus on code reading, i.e., how to make sense of the sequence of A, T, G and C’s. Others compared DNA sequences of species to identify how similar they were in molecular terms. Yet others used the predictable mutation rate of DNA as a “molecular clock” (if two species had X number of differences in parts of their DNA, then given the rate of mutation, one could calculate how long back the two species must have forked).

 

Another group became curious as to how the code (A, T, G and C) was translated into physical proteins. The answer? It involved something called a ribosome. Matt Ridley gave this metaphor a long while back:

“The ribosome did not contain the recipe for the protein: it was a tape reader. It could make any protein as long as it was fed the right tape of “messenger” RNA (which in turn was based on the DNA code).”

To me, the metaphor was crystal clear (it worked like a tape player that “reads” the cassette, and “produces” sound accordingly).

 

But there’s an even better metaphor from present day, writes David Quammen in his book, The Tangled Tree:

“Because the proteins they produce become three-dimensional molecules, a better metaphor… for our own day, might be this: the ribosome is a 3-D printer.”

 

Which reminds me of my 9 yo daughter’s question during the ongoing COVID-19 lockdown. After being told that we couldn’t order certain things since they weren’t classified as “essential”, she announced, “Who cares? Just use a 3-D printer and create it”. (She’s seen one at her friend’s house).

 

Now the seeming digression. John Wheeler, the physicist, said that physics moved changed its view from “Everything is Particles” (pre-quantum) to “Everything is Fields” (quantum) to “Everything is Information”. The last one is famously called “It from bit”. Or everything material (the “it”) can ultimately be drilled down to information (the “bit”). Or as Wheeler himself put it:

“It from bit symbolises the idea that every item of the physical world has at bottom — at a very deep bottom, in most instances — an immaterial source and explanation; that what we call reality arises in the last analysis from the posing of yes-no questions and the registering of equipment-evoked responses; in short, that all things physical are information-theoretic in origin.”

 

Biology/life and my daughter certainly subscribe to the “it from bit” theory.