Mayonnaise and the Origin of Life

What would the blog of an eminent scientist and thinker look like thirty years ago, before the word blog existed?

Welcome to Mayonnaise and the Origin of Life by theoretical biologist Harold Morowitz. Published in 1985, it’s a collection of musings – short essays of maybe ~1000 words – on a variety of topics that relate to his broad interests in science, philosophy and society. I chanced on the book at my university library while looking for something else; ah, the serendipity of browsing! It’s a bit dusty and there’s a slight residue on the covers of the book. It probably has not been checked out in a long time.

I first encountered articles by Morowitz when I became interested in origin-of-life chemistry. His writing is clear and lucid, be it a review article or one that dives into the details and weeds. I’ve learned a lot from him, and a number of his ideas have influenced the niche of the problem that I’m targeting. But that’s another story.

Mayonnaise takes its name from one of the fifty short essays. Morowitz starts with the basic recipe for mayonnaise: vegetable oil, egg yolk, and vinegar; but his main focus is on amphiphiles, dual-nature molecules that have a polar head (attracted to water) and a non-polar tail (attracted to oils). Incidentally, I just covered this topic in my General Chemistry class this morning on the thermodynamics of solution miscibility. The cells in your body, or for that matter all living things, are cells (compartments) because of the behavior of amphiphiles. These molecules are fundamental to the origin of life – and life as we know it is cell-ular. (The picture below is from an article in the journal Life showing a potential prebiotic amphiphile and how a collection of amphiphiles can form micelles and vesicles.)

In the 1980s, the “RNA world” was all the rage in origin-of-life research because of the discovery of ribozymes, RNA molecules that also behaved as catalysts. It was a possible solution to the chicken-and-egg problem of which came first: DNA or protein. DNA is excellent as genetic material because of its stability and information storage and copying structure, the double helix with A–T and G–C base-pairs. Proteins are crucial as the molecular machines in our body to catalyse chemical reactions. But proteins can’t copy themselves informationally. They are transcribed and built from DNA. On the other hand, DNA has no catalytic ability – and to make matters worse, you need catalysts to help unzip the DNA and copy itself.

While there was work looking into the role of amphiphiles in the origin-of-life, it wasn’t until the 1990s when this area of research started to take off, thanks to Pier Luigi Luisi and others. Morowitz tried to highlight their importance back in the mid-1980s. He predicted this revolution at the end of his essay. “They are of vital importance now and appear to have been equally important in the salad days of our planet. We are clearly dealing with most significant pieces of biological apparatus. If you have not been informed of them before, ignore that journalistic omission; you will hear much of amphiphiles in years to come.”

I’m halfway through Mayonnaise and two of my favourite essays so far are “Do Bacteria Think?” and “ESP and dQ over TT”. Reacting to a Supreme Court ruling that allows for genetically engineered bacterial strains to be patented, Morowitz muses that this “seemed to imply that the tiny organisms were not fully alive in the same sense that higher organisms are... What the Court did not realize was that this materialistic view runs counter to recent developments in microbiology… The new studies raise a profound question about the evolution of mind: If the simplest forms of life are capable of purposive activity, can they be said to engage in a form of thinking?” Is there a continuum of forms of thinking? Are there phase transitions that lead to a discontinuity? Are all forms of thinking just a reaction to physical and chemical stimuli? Since bacteria can sense time through variable chemical reaction rates, do they have memory?

Morowitz divides extra-sensory perception (ESP) into two categories. Information is transmitted by (1) “physical signals we have not discovered”, or (2) “methods… totally outside the range of measurement of physical devices and not energy dependent in the thermodynamic sense”. He argues that the first isn’t true ESP. We simply haven’t figured out where, how and what the sensory organs or devices are. The second, however, is much more interesting because it would violate the second law of thermodynamics. (Maybe I should bring this up in class. Ha!) Morowitz walks the reader through the measurement of entropy (dQ over T), discusses Maxwell’s Demon and Brillouin’s solution, and posits how we might then be able to “design a device to continuously convert heat into work. Among other benefits to mankind the energy crisis would immediately be solved.”

I’m looking forward to the second half of Mayonnaise. I’m slowly reading a couple of entries per week. Each takes less than 5 minutes, but then I spend the next 10 minutes thinking about it before remembering that I should be doing something else! So if you find an old dusty copy in your library, I recommend it!