I should have loved biology

By James Somers

I should person loved biology but I recovered it to beryllium a lifeless recitation of names: the Golgi servants of the state and the Krebs cycle; mitosis, meiosis; DNA, RNA, mRNA, tRNA.

In the textbooks, astonishing facts were presented without astonishment. Someone astir apt told maine that each compartment successful my assemblage has the aforesaid DNA. But nary 1 shook maine by the shoulders, saying really crazy that was. I needed Lewis Thomas, who wrote successful The Medusa and the Snail:

For the existent amazement, if you wish to beryllium amazed, is this process. You commencement retired arsenic a azygous compartment derived from the coupling of a sperm and an egg; this divides successful two, past four, past eight, and truthful on, and astatine a definite shape location emerges a azygous compartment which has arsenic each its progeny the quality brain. The specified beingness of specified a compartment should beryllium 1 of the awesome astonishments of the earth. People ought to beryllium stepping astir each day, each done their waking hours calling to each different successful endless wonderment, talking of thing isolated from that cell.

I wish my precocious schoolhouse biology coach had asked the people really an embryo could perchance differentiate—and past paused to fto america really deliberation astir it. The full taxable is successful the reply to that question. A chemic gradient successful the embryonic fluid is capable of a awesome to somewhat change the cistron look programme of immoderate cells, not others; now the embryo knows “up” from “down”; cells astatine 1 extremity statesman producing different proteins than cells astatine the other, and these, successful turn, merchandise much refined chemic signals; ...; soon, you person encephalon cells and ft cells.

How travel we memorized chemic formulas but didn’t talk astir that? It was only successful college, erstwhile I publication Douglas Hofstadter’s Gödel, Escher, Bach, that I came to understand cells arsenic recursively self-modifying programs. The connection unsocial was evocative. It suggested that the embryo—DNA making RNA, RNA making protein, macromolecule regulating the transcription of DNA into RNA—was for illustration a mini Lisp program, pinch macros begetting macros begetting macros, the root codification containing wrong it each of the instructions required for life connected Earth. Could thing much absorbing beryllium imagined?

Someone should person said this to me:

Imagine a flashy spaceship lands successful your backyard. The doorway opens and you are invited to analyse everything to spot what you tin learn. The exertion is intelligibly millions of years beyond what we tin make.

This is biology.

–Bert Hubert, “Our Amazing Immune System”

In biology class, biology wasn’t presented arsenic a quest for the secrets of life. The textbooks wrung retired the questing. We were obscurity acquainted pinch existent biologists, the existent questions they had, the existent experiments they did to reply them. We were conscionable fixed their conclusions.

For lawsuit I ne'er learned that a man named Oswald Avery, successful the 1940s, puzzled complete 2 cultures of Streptococcus bacteria. One had a unsmooth texture erstwhile grown successful a dish; the different was smooth, and glistened. Avery noticed that erstwhile he mixed the soft strain pinch the unsmooth strain, each procreation aft was smooth, too. Heredity successful a dish. What made it work? This was 1 of the astir breathtaking mysteries of the time—in truth of each time.

Most experts thought that macromolecule was someway responsible, that traits were encoded soupily, via differing concentrations of chemicals. Avery suspected a domiciled for nucleic acid. So, he did an experiment, 1 we could person replicated connected our benches successful school. Using conscionable a centrifuge, water, detergent, and acid, he purified nucleic acerb from his soft strep culture. Precipitated pinch alcohol, it became fibrous. He added a mini spot of it to the unsmooth culture, and lo, that civilization became soft successful the pursuing generations. This fibrous stuff, then, was “the transforming principle”—the long-sought supplier of heredity. Avery’s research group disconnected a frenzy of activity that, a decade later, ended successful the find of the double helix.

In his “Mathematician’s Lament,” Paul Lockhart describes really schoolhouse cheapens mathematics by robbing america of the questions. We’re not conscionable asked, hey, really overmuch of the triangle takes up the box?

That’s a puzzle we mightiness delight in. (If you driblet a vertical from the apical of the triangle, you extremity up pinch 2 rectangles trim successful half; you observe that the area wrong the triangle is adjacent to the area outside.) Instead, we’re told that if you ever find yourself wanting the area of a triangle, here’s the procedure:

Biology is for illustration that, but worse because it’s a messier subject. The facts look other arbitrary. We’re told to separate “lipid bilayers” from “endoplasmic reticula” without knowing why we attraction astir either successful the first place.

Enormous subjects are champion approached successful thin, heavy slices. I discovered this erstwhile first learning really to program. The textbooks ne'er worked; it each only started to click erstwhile I started to do small projects for myself. The task wasn’t conscionable information but an organizing principle, a magnet to put the random robust filings I picked up on the way. I’d attraction to study astir immoderate absurd concept, for illustration “memoization,” because I needed it to lick my problem; and these concepts would suffer their abstractness successful the ray of my example.

Biology is nary different. Learning originates pinch questions. How do embryos differentiate? Why are my eyes blue? How does a hamster move food into muscle? Why does the coronavirus make immoderate group overmuch sicker than others?

*

A fewer months ago, I started a magazine assignment to reply immoderate questions astir SARS-CoV-2 and the immune system. I encountered paragraphs for illustration this:

In low-MOI infections (MOI, 0.2), exogenous look of ACE2 enabled SARS-CoV-2 to replicate and comprise ~54% of the full sounds mapping much than 300x sum crossed the ~30-kb genome (Figures 1A and 1B). Western blot analyses corroborated these RNA-seq data… It is noteworthy that, contempt this melodramatic summation successful viral load, we observed neither activation of TBK1, the kinase responsible for IFN-I and IFN-III expression, nor induction of STAT1 and MX1, IFN-I-stimulated genes (Figure S1A; Sharma et al., 2003)…

–“Imbalanced Host Response to SARS-CoV-2 Drives Development of COVID-19,” Cell

It was difficult to get done a condemnation without having to consult Wikipedia. In immunology successful peculiar the nomenclature is expansive. One condemnation mightiness mention to “leukocytes,” the adjacent to monocytes, the adjacent to lymphocytes. There are a batch of squares-and-rectangles situations: each interleukins are cytokines, but not each cytokines are interleukins?

I’ve ne'er travel crossed a taxable truthful fractal successful its complexity. It reminds maine of computing that way. A time of programming mightiness impact constructing an elaborate regular expression, investigating a record descriptor leak, debugging a title information successful the exertion you conscionable wrote, and reasoning done the interface of a module. Everywhere you look—the compiler, the shell, the CPU, the DOM—is an abstraction hiding lifetimes of work. Biology is for illustration this, conscionable much, overmuch worse, because surviving systems aren’t intentionally designed. It’s each a large slop of world mutable state. Control is achieved by upregulating this point while turning down the promoter of that thing’s repressor. You deliberation you cognize really thing works—like erstwhile I thought I had a grip connected the neutrophil, an important front-line subordinate successful the innate immune system—only to study that it comes successful respective flavors, and much are still being discovered, and immoderate of them look to do the other of the ones you thought you knew. Everything successful biology is for illustration this. It’s each exceptions to the rule.

But biology, for illustration computing, has a bottom, and the bottommost is not abstract. It’s physical. It’s shapes bumping into each other. In truth the awesome revelation of twentieth-century molecular biology was the coupling of building to function. An aperiodic crystal that forms paired helices is the earthy shop of heredity because of its expertise to curl up and unwind and double itself pinch complements. Hemoglobin, the first macromolecule studied successful afloat crystallographic detail, was shown to beryllium an businesslike shop of power because of really oxygen atoms threat into its assemblage for illustration Legos, each threat widening the remaining slots, truthful that it loads itself up practically astatine a gulp. Most proteins are for illustration this. The ones that thrust locomotion twist for illustration small motors; the ones that statement muscles climb and compress each other. Cells, too, are perpetually successful conversation, and the connection they speak is shape. It’s keys entering locks: a macromolecule mightiness straddle the compartment membrane, and erstwhile a cytokine (that’s a benignant of signaling molecule) docks pinch it, it changes its shape, truthful that its grip loosens connected immoderate different molecule connected the interior broadside of the membrane, arsenic though fumbling a football—that shot mightiness beryllium a awesome itself, connected its measurement to the nucleus.

I deliberation my knowing of biology was excessively flow-charty successful precocious school. I knew that DNA → RNA → protein and that this was called “gene expression,” but I was confused connected the basics, like, really did genes really “turn on”? And erstwhile they were on, were they connected for good? It’s clearer erstwhile you deliberation physically. Mammalian DNA isn’t laid retired arsenic 1 agelong double helix; it’s tightly coiled and coiled again, for illustration this, astir small information proteins called histones:

The building of the resulting fibre has an effect connected which genes are expressed. This is because the small molecular instrumentality that transcribes DNA into RNA has to really ride on the helix, and it tin only thrust on immoderate parts of it, namely the parts that aren’t curled up retired of sight. “Expressing” a cistron conscionable intends that astatine a fixed moment, the instrumentality is accessing a circumstantial information of DNA, resulting successful tons of RNA transcripts, resulting successful tons of the macromolecule that the cistron codes for. Kink the fibre a spot and you alteration what the instrumentality tin see, frankincense changing the distribution of proteins it produces. You person “reprogrammed” the cell. (There are galore ways to power cistron expression, possibly the astir communal being “repressors” that parkland location connected the DNA, physically blocking the transcription machinery.)

One of the workhorse techniques successful modern biology, called RNA sequencing, aliases RNA-seq for short, takes a stiff compartment and counts the RNA transcripts wrong it. In effect you get a snapshot of each the proteins being expressed astatine that moment. The consequence is virtually a large array mapping genes to transcript counts. You spot that being 1 benignant of compartment versus another—or being successful 1 benignant of cellular temper versus another, opportunity successful wellness versus disease—is conscionable a matter of having a different distribution crossed this table. RNA-seq results are often represented arsenic vectors successful high-dimensional space, the counts successful the array forming the coordinates; cells move done this look abstraction arsenic they self-regulate and accommodate to their environment.

*

How do you create a beingness knowing of biology? I for illustration pictures. One of my favourite books is called The Machinery of Life, by David Goodsell. It’s afloat of gorgeous hand-drawn illustrations. Here a bacterium’s flagellar centrifugal is shown successful context, past zoomed successful connected successful an inset, pinch a 3rd image highlighting its functional elements:

What makes the book activity is that it’s fundamentally a re-introduction to molecular biology pinch the pursuing premise: the compartment is a very accelerated and crowded place, afloat of small machines, astir of them protein, which you understand by taking a adjacent look. It does an particularly terrific occupation done insets for illustration the supra relating things astatine different scales. “Imagine your room filled pinch grains of rice. That will springiness you an thought of the cardinal aliases truthful cells that dress up your fingertip.”

The penning is very good. It someway gets you imagining the motion of these machines. It’s tempting erstwhile reasoning astir the cellular world to simply miniaturize our own; but astatine the cellular standard things behave weirdly. Movement is fundamentally by random diffusion. “The motions and the interactions of biologic molecules are wholly dominated by the surrounding h2o molecules… Inside the cell, [a] macromolecule is battered from each sides by h2o molecules. It bounces backmost and forth, ever astatine awesome speed, but takes a agelong clip to get anywhere.”

It turns retired that random diffusion is an incredibly slow measurement to recreation ample distances, but an incredibly accelerated measurement to research astatine short distances. Being a macromolecule wrong a compartment is for illustration being astatine a crowded location statement wherever it mightiness return an hr to get crossed the room, but by the clip you get location you’ve bumped into everybody six 100 1000 times.

This constituent is made beautifully successful different favourite book of mine, A Computer Scientist’s Guide to Cell Biology, by William W. Cohen:

Molecules that travel adjacent to an organelle thin to stay adjacent to it for a while, and brushwood against it galore times—Figure 20 gives immoderate intuitions arsenic to why this is true.

The consequence of this is that if receptors for a macromolecule p screen moreover a mini fraction of the aboveground of an organelle, the organelle will beryllium amazingly businesslike astatine recognizing p. As an example, if only 0.02% of a emblematic eukaryotic cell’s aboveground has a receptor for p, the compartment will beryllium astir half arsenic businesslike arsenic if the full aboveground were coated pinch receptors for p.

This is the benignant of truth that instantly clarifies really biology could perchance work. “Cell-sized objects frankincense person a ‘high bandwidth,’” Cohen writes. “They tin admit aliases sorb hundreds of different chemic signals, moreover if they are bounded by membranes.”

Cohen’s book is sounded arsenic an effort to distill what he learned successful acquiring a “reading knowledge” of biology—enough to beryllium capable to travel on pinch a insubstantial successful Cell. He’s very bully astatine explaining methods: really do biologists cognize what they know? For a machine scientist, a biologist’s methods tin look insane; the problem comes from the truth that cells are excessively small, excessively numerous, excessively analyzable to analyse the measurement a programmer would, opportunity successful a step-by-step debugger. What biologists mostly do is worldly like:

• Spin things to 15,000 Gs successful centrifuges to abstracted pieces having different densities.
• Separate things of different sizes utilizing gels and magnets. (“Gel electrophoresis.”)
• Take 1 of those gels and blot it pinch typical insubstantial to splay the parts out. Then lavation the insubstantial pinch an antibody that binds to a circumstantial protein. Finally, lavation the insubstantial pinch another antibody that binds to the first one, and fluoresces erstwhile it does so. See wherever the meta-antibody lights up—that’s the macromolecule you were looking for. (I deliberation I’m describing a “Western blot.”)
• Use the fluorescent antibody instrumentality to tag cells expressing 1 aliases much proteins of interest. Then compression the cells done a conduit truthful mini that only 1 fits astatine a time. As each compartment passes by, radiance a laser done it to publication its fluorescent tags, and usage an electrical complaint to redirect it to a peculiar bin. Now you tin benignant and count cells that lucifer your criteria. (“Flow cytometry.”)
• Genetically change microorganisms to make molecular machines to spec; systematically move disconnected 1 cistron astatine a clip successful a compartment statement and spot what changes; edit the genome of a full animal, and observe its life.

Cohen found, and I person too, that successful trying to get a reference knowledge of biology it’s almost much useful to study the methods than immoderate individual facts. That’s because the methods are highly conserved crossed studies. Everybody does Western blots. Everybody does travel cytometry and RNA-seq. You’ll spot this worldly successful each paper. (Or variations connected the aforesaid themes: separation, sorting, selection, familial manipulation.)

So that’s the foundation. Or almost: I person near for past my favourite assets of all, an unthinkable book called The Eighth Day of Creation: Makers of the Revolution successful Biology, by Horace Freeland Judson. Parts of this book were serialized successful the New Yorker successful the 1970s. It is the Power Broker of biology, a tomic masterwork. It is not conscionable comprehensive—Judson had hundreds of conversations pinch Francis Crick, pinch Jacques Monod and François Jacob, pinch their friends and spouses and colleagues; he publication each paper, he publication each their letters—but it pulls nary punches scientifically. Judson ever conscionable describes the existent thing.

And he emphasizes incorrect turns. For example, earlier the find of tRNA—the adapter molecules that nexus triplets of RNA bases to the amino acids they codification for—there was overmuch confusion. It was wide believed that location had to beryllium immoderate benignant of punctuation, because really other would 1 cognize wherever to commencement transcribing, aliases really to delimit 1 codon from the next? Certain intelligence models were ingrained: a going mentation was that RNA formed specially shaped pockets for the different amino acids. The thought was that if you zoomed successful connected each triplet aliases quartet aliases immoderate (the strategy was past unknown), it would ever shape the aforesaid unsocial style that only 1 benignant of amino acerb could fresh into. The amino acerb concatenation would beryllium formed correct location alongside the RNA strand, utilizing it almost arsenic a mold. This was thought to hap successful the nucleus. The thought that macromolecule synthesis happened via an adapter, and that the nucleic acids truthful acted little for illustration a mold than a integer code, much purely information—this was a awesome surprise.

Sitting connected the writer astatine Woods Hole, Crick was talking astir genes and proteins, successful peculiar astir his presumption that they were colinear and Benzer and Brenner’s scheme to show arsenic much, erstwhile Ephrussi took him aback by asking really he knew that amino acids were not put successful their superior series by thing successful the cytoplasm. . . . “I don’t deliberation Boris needfully believed it, but it was an thought he thought wasn’t impossible.”

. . .

Crick besides formed his skeptical oculus complete Watson and Rich’s attempts to build models of RNA. “Of course, you recognize that our ideas connected that were wholly wrong. We thought that RNA had immoderate building pinch the 20 cavities, it was that period. Mm-hmm. Unfortunately group person forgotten what it is we didn’t cognize astatine the time.”

Put different way, the book gives america a position of subject before discovery. It is simply a practitioner’s position of the subject. It is the other of a textbook.

*

Trying to study the immune strategy has gotten maine into a Bret Victor benignant of mood, wondering what could beryllium done, aliases built, to make knowing this taxable easier. A fewer things travel to mind:

There are immoderate unthinkable YouTube explainers. Ninja Nerd Science’s videos connected the immune strategy were a miracle—all delivered by a kid successful grad school. He is simply a genius. What he does truthful good is what Goodsell, successful that Machinery of Life book, does truthful well, what those celebrated “Inner Life of a Cell” 3D animations do truthful well: he helps you “see the unseeable.”

But I wonderment whether it should beryllium easier for regular group to create useful illustrations. Consider really easy it is to write, tooling-wise: connected the web, you are only ever 1 click distant from a Markdown-enabled textarea that allows you to create and people pretty, hyperlinked documents. Anyone pinch a keyboard tin lend a fewer sentences to Wikipedia aliases reply a mobility connected Stack Exchange. Drawing, by contrast, is hard, and animating is astatine slightest an bid of magnitude harder. And yet these media are basal for knowing biologic processes.

So what do we do?

It’s telling that erstwhile I was precocious connected a Zoom pinch a PhD student who was explaining RNA-seq, he pulled retired his iPad Pro and fundamentally made a Khan Academy speech arsenic he talked, drafting on the way. These devices request to go much communal and cheaper.

But we besides request much package for illustration pattern brushes successful Adobe Illustrator, BioRender, and CellPAINT to make it un-tedious to tie analyzable objects. We request much package for illustration Molecular Maya, but simplified moreover further, à la Victor’s Stop Drawing Dead Fish, to make animating accessible to anyone who tin gesture.

Using vector graphics and Undo history, it should beryllium imaginable to make collaboratively editable images, i.e., images that tin beryllium slow improved arsenic portion of a knowledge task for illustration Wikipedia aliases Stack Exchange.

I want to beryllium capable to return a screenshot of the whiteboard successful a Ninja Nerd lecture—a large beautiful sketch of the players successful the adaptive immune system—and lasso sections of it, linking to sub-diagrams, immoderate filled successful by me, immoderate by others, illustrating each of the parts successful turn. We should person big, collaboratively edited zoomable “maps”—hierarchical diagrams—that are easy to navigate, activity successful modular browsers, are embeddable successful blog posts, and truthful on.

Of people we request to thatch much group really to draw. It’s an underrated skill. And really to constitute vividly, arsenic successful the awesome books above.

But biology is uniquely suited to simulation—it’s a world of machines that are excessively mini to see. The problem is, it requires excessively overmuch specialized accomplishment to create three-dimensional interactive simulations. We request a toolkit that’s for illustration MockMechanics, aliases Minecraft, that possibly moreover is Minecraft, but focused connected biology. Or thing overmuch better.

It’s nary coincidence that Watson and Crick depended for their find connected a literal physical model that was machined for them specially. Victor’s Dynamicland imagines an immersive collaborative abstraction successful which specified models tin beryllium built—now that we person computers—as quickly arsenic you tin person a conversation.

This is precisely what I wanted arsenic I was penning my immune strategy article. I wanted to conjure models I could play pinch successful my hand. I wanted a depository wherever I could locomotion astir wrong the epithelium during an immune response. I wanted to put ideas into beingness space, for illustration connected a pinboard—TLRs spell here, pinch the different innate armament; CD4+ T cells are there, successful the adaptive world—but I wanted it to beryllium arsenic searchable, copy-pasteable, shareable, and composable arsenic text.

I deliberation we besides request inspiration. There is simply a romance successful biology, arsenic successful immoderate different science, that a movie for illustration Good Will Hunting could bring out. We request heroes. Whoever delivers america from this pandemic successful the shape of a slam dunk vaccine, aliases a inexpensive speedy reliable test, should go a family name, not for their ain glory but for our kids—a Feynman for them to dream astir someday becoming.

Reading list

• The Machinery of Life, David Goodsell
• Bionanotechnology: Lessons from Nature, David Goodsell
• A Computer Scientist’s Guide to Cell Biology, William W. Cohen
• The Eighth Day of Creation: Makers of the Revolution successful Biology, Horace Freeland Judson
• The Medusa and the Snail: More Notes of a Biology Watcher, Lewis Thomas

See jsomers.net for much of my writing.