Time And Life : 13.7: Cosmos And Culture From the perspective of a biologist, the question of time is far more mundane, because organisms exist in the classical realm we call chemistry.
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Time And Life

Time present and time past

Are both perhaps present in time future,

And time future contained in time past.

If all time is eternally present

All time is unredeemable.

What might have been is an abstraction

Remaining a perpetual possibility

Only in a world of speculation.

What might have been and what has been

Point to one end, which is always present.

Footfalls echo in the memory

Down the passage which we did not take

Towards the door we never opened

Into the rose-garden…

T.S. Eliot, Burnt Norton

A foundational difference between Eastern and Western philosophical/religious perspectives relates to time. Buddhist and Hindu teachings speak of beginninglessness, the notion that all things are interdependent, and hence mutually causal, and hence cannot have originated but must always have been. By contrast, the Abrahamic traditions have been preoccupied with creation and right-relationship with a Creator. In his Christian-steeped Four Quartets, poet T.S. Eliot writes: “If all time is eternally present all time is unredeemable.”

Adam and Marcelo have treated us this week to perspectives on time from scientific cosmologists, where things quickly become philosophical and even religious. I’ll close out the week with some time-perspectives from a biologist, where things turn out to be far more mundane.

Organisms on this planet – regardless of how one thinks of their place in cosmological frameworks – exist in the classical realm we call chemistry, more specifically, biochemistry. Chemistry is, of course, emergent from the quantal realm and can be analyzed from that perspective, but the all-important second law of thermodynamics -- ΔG = ΔH - TΔS – can be articulated with nary a quantum concept because it describes what happens when quantal effects are averaged out over much larger scales. Embedded in each of those deltas is the concept of change over time; embedded in the = function is the concept that those changes will arrive, with time, at an equilibrium state where there is no net change. As Stu often reminds us, each trajectory that is followed is guided by the as-yet-unrealized “adjacent possible,” but both “adjacent” and “possible” are themselves temporal terms; as he notes, the possible does not exist timelessly, but constantly responds to time-bound actualities. What an organism effectively accomplishes, then, is to constrain its biochemistry such that it feeds into adjacent possibles that allow self-organization and hence continuation, once again a temporal term.

As I’ve expanded in an earlier blog, much can be said about the dynamics of life’s constraints. But in the context of time, we can focus here on a feature of life that was (arguably) invented after the invention of constrained life-like organisms, namely, the encoding of instructions, in a separate medium called DNA, for accomplishing self-organization and self-maintenance. As most people know, DNA is composed of genes that encode the structure of proteins. Some of the proteins catalyze the biochemistry and others construct the cell wherein the biochemistry takes place, where catalyze and construct are both temporal verbs.

That could have been the end of it. But what in fact evolved was yet another temporal layer: the regulation of gene expression in time. Some genes give rise to their encoded proteins under some temporal circumstances while others do so under other circumstances, where the “switching” activities are carried out by regulatory proteins encoded by regulatory genes that are themselves temporally regulated by complex feedback loops that are in turn highly dependent on changing (temporal) environmental cues.

Hence even the simplest bacterium (and bacteria are by no means simple) contains one set of proteins at one time and a different set of proteins at a different time.

But it gets even cooler than that with multicellularity. In land plants and animals, the fertilized egg expresses one subset of genes and then, as the zygotic cells divide, daughter lineages come to express novel subsets of genes not only in time but also in space, the animal outcome being an incipient heart here, an incipient liver there, an incipient brain somewhere else. Even better, most such developing cells acquire the ability to secrete hormones or establish direct contact such that they influence the differentiation of one another. The timing of these cell-cell interactions is itself exquisitely controlled, as witnessed by the abortive results if they are compromised by mutation or external manipulation.

As humans, these temporal underpinnings to our existence are masked from our self-narratives. We experience time as Eliot describes – as past, present, and future modalities, as that which we don’t have enough of, as that which may or may not end when we die. But without time, the capacity to construct these self-narratives would not have materialized.