From the Whole to the Part and Back

I studied physics seduced by the belief that all phenomena could be explained by one simple and unifying law. Convinced that I was, I devoted my PhD to delve into the old paradox: how can the irreversible macroscopic behavior observed in nature be reconciled with the time-reversible dynamics governing microscopic processes? Four years in a quiet room with pen and paper is a long time to think about why, when you drop a glass, it breaks into a thousand pieces, but the scattered shards never rise up off the ground back into your hand, spontaneously reforming an intact glass.

While reaching a satisfactory understanding of these beautiful abstract concepts, I started to feel attracted – or maybe distracted – by the colorful spectrum of problems biology offers. For personal reasons (it is curious that we need to invoke causation to justify every decision we make in life), I put my physicist spirit in a wetsuit and dived into a neurobiology laboratory for my first post-doctoral adventure. It was tough. I felt naive and lost. A foreigner in a culture with different beliefs and a strange language. A vector was not a geometric entity anymore but, instead, a plasmid. As a speaker with no mouth and lots to say, I decided to be patient, learn the language and follow the customs. My beloved equations were suddenly exiled by behavioral experiments in a dark room, tracking Drosophila larvae as they navigated in odor gradients. The big picture was clear in the back of my mind: to understand how the nervous system computes information in a model organism. The reality was that my days were spent watching maggots crawl up and down! My theoretical physicist ego was not ready to bear such activity. I felt miserable knowing that preparing an odor dilution would take me more time than solving a non-trivial integral by hand. As it turns out, both exercises are recommendable. The other side of the coin is that I experienced the excitement of watching nature happening live, and the pleasure of generating my own data. I will never forget the night at the Cold Spring Harbor Laboratory summer course when I made my first larval preparation, stuck an electrode in the neuromuscular junction and induced an action potential. That action potential on the screen had a flavor of reality a formula cannot describe.

Already two years have passed and things have progressed. I now belong to the systems biology ecosystem. However, I very often feel that understanding is sacrificed in the name of pure discovery. Assuming it is neither money nor pride, what is it that satisfies our research efforts: insight or surprise? The “eureka!” or the “wow!”? I compile rather than pile facts. I will confess an obvious secret: there are different ways to ask “how” and we need not limit our choice to one. By removing our obsolete defenses detailed mechanisms and abstract principles cease to be in contradiction and start working in conjunction. We, postdocs, are highly-qualified specialists in “something”. I encourage you to use your power to beat irreversibility: to break a problem into a thousand pieces (like the glass), and then be able to integrate it as a whole. Navigating in a complex world, it is possible to enjoy the commute from the whole to the part and back.