What’s the difference between me and you?
You talk a good one, but you don’t do what you supposed to do
I act on what I feel and never deal with emotions
I’m used to livin’ big dog style and straight coastin’
— Phish
It’s impossible to think of a theory of everything if mathematics has yet to solve this problem.
David Hilbert was convinced that a set of finite axioms is enough to explain mathematics. Kurt Gödel proved that it is logically impossible. And since physics rests on the shoulders of mathematics, finding a theory of everything becomes tenuous.
Still, we have to try. An element of useful delusion is necessary. It’s how we get new ideas. By trying. This is the effort evolutionary biologists have resorted to in creating a theory that should have parallels in physics.
Hailed as the top-tier science, physics has attained levels no other field has ever achieved. At first, it was a deterministic world. This turned probabilistic after the introduction of quantum field theory. And now, everyone is trying to achieve the same feat. But imitation, however flattering it may be, introduces sterility to any field. That was the problem with trying so hard to replicate the achievements observed in physics. Some similarities exist, but focusing too much on these goals injects macular vision in the scientists. We need to acknowledge where the fields differ if there is ever to be progress.
A spherical cow
A biologist may want to know the average weight of an adult Zebu. They may not have the best model, so they reach out to a physicist who promises to help. The following day, she comes with the following first assumptions:
Assume the cow is spherical.
This is how simplistic models in physics have to be for them to be tested. Variables have to be phased out, and strong assumptions have to be made for analyses and experimental tests to be conducted. We may not see an atom, but we may have an instrument that lets us detect the noted features with consistency. The same goes for quarks.
Scientists then hope that their model stands up to all forms of tests, despite their simplicity. The most successful so far is the Standard Model. Physicists can confidently claim that they have discovered all the fundamental particles of the universe.
Biology is anything but simple. Yet, we try to simplify it to match physics. David Krakauer, the president of the Santa Fe Institute, likes to remark that physicists have struggled to find the theory of everything, but not the beings creating it. In short, biology has various forms of irreducibility that cannot be atomized or simplified, as in the case in most physics models.
But this doesn’t stop others from trying.
The equivalent of fundamental particles is the gene. Among biologists, the fundamental unit of heredity is the gene. This word has different meanings in different fields. To someone in the lab, it is a portion of the DNA. It should code for a protein. To the evolutionary biologist, it is a unit of heritable information, passed down through generations. It doesn’t have to be through the DNA. And yet, there is an issue trying to imagine information passed from one generation to another without a robust vehicle that isn’t DNA.
Physicists don’t quarrel about the fundamental particles. Biologists, in contrast, disagree on what the gene is.
After Watson and Crick developed the double-helix model, it was unassailably accepted that the gene is the part of the DNA that codes for proteins. It means many eukaryotes had pieces of their DNA that were worthless, effectively called junk DNA. Later, more studies revealed that there are genes in the DNA that are passed down through generations, involved in regulation, and don’t necessarily code for proteins. Because of years of popularized jargon, they gave it a leftover name: non-coding genes.
Even if we’re to assume there is no disagreement about the meaning of a gene, we still encounter problems synonymous with the spherical cow. A gene does not have direct effects, easily calculated like that of our spherical mammal. One gene may have several effects (pleiotropy) and several genes may be needed for a single outcome (polygenic inheritance). And there’s a third one, where genes interact together to influence an outcome (epistasis).
This means a mutation of one gene can have effects on multiple seemingly unrelated phenotypes. For example, a mutation responsible for the sickling of red blood cells will have an effect on multiple organs, from the eye to the long bones and the spleen.
Epistasis is the reason Sewall Wright and Ronald Fisher disagreed. Fisher focused on the additive effect of genes, but Wright accurately argued that some genetic changes are epistatic. In addition, while Fisher focused on large numbers, Wright emphasized smaller populations, whose effects are out of kilter with the large ones. Alongside J. B. S. Haldane, these two are regarded as the founding fathers of population genetics, but they didn’t agree on what should potentially be the “fundamentals” of evolutionary biology.
Some elements cannot even be boiled down to these supposedly fundamental features. Morphogenetic fields (as described by Brian Goodwin), for instance, require several elements of a cell or groups of cells to form. By creating cellular gradients, a cell can know its position and which definitive cell it should become. The process can be reversed when it’s exposed to various factors, popularly known as the Yamanaka factors.
Cellular reversibility in the presence of these factors may give the impression that cells are like the fundamental particles with reference to time. Assuming these particles are like billiard balls, their interactions should not be able to tell the forward and backward directions of time. But this is a false approximation.
Diseases reveal that certain exposures make impossible genetic changes. Diabetes is no longer only about sugar control. A physician needs to focus on the legacy effect of sugar and the associated systemic outcomes. Diabetes is now to be viewed as a metabolic disease, and metformin is not the go-to first choice for every newly diagnosed case. And why the legacy effect? Because there are irreversible changes that accompany poorly managed diabetes.
The cell is the basic structural and functional unit of life. Biologists, at least, agree on this. Reversibility should imply the eukaryotic cell should, given the proper factors, change to become prokaryotic, like archaea or bacteria. This is impossible.
Even among asexual species, there’s a cap beyond which the absence of sexual reproduction introduces lethal, irreversible mutations — Muller’s Rachet. Biology is not physics.
Perhaps the part that makes it extremely different to merge the two disciplines is in consciousness. Like life, we have no crisp definition of consciousness, but there’s an agreement on what it should be like. Thomas Nagel’s essay is the primary reference.
While physics depends on the objectivity of its test material, biology is left with subjective beings. Consciousness is the felt experience of an organism. What it is like for it to be organism X. Subjective. Expose two similar organisms to the same stimulus, and they react differently. The subjective features cannot be reduced to the inanimate. Feynman thanked the heavens that electrons don’t feel in the sense organisms do.
Despite this, we try to derive physical laws that can be transmuted to biology. After all, we need an explanation for how abiotic elements and particles resulted in organisms as complex as ourselves. Jeremy England has developed one such hypothesis, known as adaptive dissipation. I have also developed another, which focuses on persistence, of which adaptation is a feature. I call it the singularity hypothesis. These attempt to show that the features we see in biology do not break the fundamental laws of physics.
Had we stopped pushing, thinking the two fields were worlds apart, we never could have developed these ideas. Economics is another example that appears to be different from ecology. From an etymological point of view, economics is derivable from ecology. Because experts from these separate fields have different views, they have advanced their respective fields. As is the case in biology, where complexity has emerged as a field in its own right, it captures the nuances seen in biology, but overlaps with other domains.
Trying to shoehorn a field into another may not be the best idea. Chasing elegance through simplicity, as artistic as it sounds, may stall our creative endeavours. The approach I would rather we consider is to take something simple first and take it seriously. Then, one can trace the similarities if at all they exist, rather than believe they are the same. One field is not a Procrustean bed for the other.
Perhaps a good example is electrons and black holes. Electrons are subatomic. Black holes are colossal. Yet, these two forms of matter, in the same domain, have similar simple traits such as spin, mass and charge. Particle physicists and astrophysicists focus on separate areas of physics, but they have taken each seriously enough. After much study, they realised they converged on certain features.
Since the goal of the scientist is to be accurate and correct, they tend to converge in their solutions. It’s not like beauty, which can diverge. Thus, our best approach, I would argue, is to consider fields as different. Synthesis will come later.
What I’m trying to say is…
I am a big fan of synthesis. However, premature synthesis can potentially stunt a field.
Creativity is irrational, and it should be irrationally pursued. It is necessary for the development of solutions to our biggest problems. To grant scientists this degree of freedom, we have to believe that the field is unique, separate, and standalone. After much research, we can trace similarities, if at all they exist.
But for now, I have yet to see a spherical cow.
That’s the difference
This song inspired some of the lines used in this article. Source — YouTube