Standardization

Life seems complicated. The molecules of life look complicated, perhaps idiosyncratic. For a while, even chemistry was divided between organic chemistry pertaining to life and inorganic chemistry pertaining to non-life. How did the molecules of life arise if there are two separate chemistries? Anecdotally, the unification of these two strands is attributed to Wohler’s synthesis of urea (organic!) from inorganic materials in 1830. But more likely the philosophical shift took place over many years and many experiments. Chemistry departments the world over still offer organic and inorganic chemistry, a testament to history certainly, but perhaps also to standardization.

 

The birth of origin-of-life chemistry, where my current research interests lie, is attributed to the spark-discharge experiments of Stanley Miller first published in 1953. Starting with water and the simple gases methane, ammonia, and hydrogen, Miller synthesized amino acids in seven days – a new story of creation! Several of these amino acids such as glycine, alanine, and aspartic acid, were proteinogenic – they are part of the “standard” set found in extant proteins, the workhorses of life today. But other amino acids, not part of the standard set, were also present in the mixture. Further experiments reinforced the fact that molecules (with carbon backbones) not pertaining to life were synthesized in far greater quantity and diversity than the molecules life utilizes.

 

My students are initially surprised when I tell them that the riddle of origin-of-life chemistry is not how to make the molecules of life from simpler substances. That’s easy. The more challenging question is how and why life “chose” to utilize only a small subset of what is synthesized – many of these molecular “cousins” are closely related size-wise or property-wise to the chemicals of life. Having pondered this, I can speculate on the why. I think that for mass production to be feasible (through replication or reproduction – slightly different things), there must be standardization. The large family of potential molecules must be pruned to allow efficient and self-sustaining mass production. The remaining question – the how – that’s what I’m hoping to elucidate as part of my research program, so I don’t know the answer yet.

 

Why is standardization important for mass production? Imagine trying to build a house or some sort of edifice with a whole bunch of rocks that are different in size and shape. Not so easy if you want a strong stable structure. You’ll need the right shape and sized rocks to fit together snugly. Now imagine you wanted to build many such structures. I suspect it would very inefficient. But what if you started shaping the rocks a little so that you have several standardized shapes that fit well. You’re on to something, and your stone age village can now outgrow and therefore outcompete the neighboring village. You’ll have to expend some extra energy though; you’ll need appropriate tools and time for the rock-shaping and some degree of organization and division of labor to streamline the process.

 

The history of technology is replete with such examples of standardization: ubiquitous bricks, humble screws, tiny ball bearings, and can’t-live-without microchips. But standardization comes in other forms, grades of beef being the example often being linked to why we have grades in school. We have standardized curricula, at least in the sciences and mathematics. At the college-level, here in the U.S., many tertiary educations follow the standards set by the American Chemical Society. Our degrees are annually certified by this body – a standardization of sorts that signals a potential employer or graduate school that our graduates have the requisite standard know-how.

 

But to maintain standardization, cooperation and control are required. Things get more complicated and complex (again, slightly different things). Other structures must be built to keep the machinery chugging along for mass production. Regulation kicks in, as do feedback loops. Error-correction mechanisms show up. Becoming byzantine may not be a choice if you want to be top dog, defeating all rival villages and subsuming them into your sphere of influence. (Or even if you want to promote mass cooperation.) You’ve got to keep running, like the Red Queen, even if only to stay in place and not fall behind into dissembly. We see this in the rise and fall of city-states and empires of history. We see this in the birth, life, and death, of living organisms from bacteria to humans. Standardization is a part of life. But it remains fragile.