Bonus Chapter

You know what they say about killing your darlings. Well, sometimes that means cutting an entire chapter. While I quite like this piece of writing, which was originally the second chapter of the book, I decided relatively early on that it would take the focus too far from the central theme of the book, which is the focus on Daredevil’s heightened senses.


Radiation, Mutations, and Superpowers

“Now hear this, Earth! I am Mutant Man, Homo Superior! I have been created by radiation forces out of the loins of you, the human race, after your great and terrible Atom War. Yes, I am a step above and beyond you and I am now your master for better or for worse. You created me in your blind, savage, senseless war of atomic radiation. You have only yourselves to blame if I turn out to be your – Frankenstein Monster!”

How Nuclear Radiation Can Change Our Race, by O. O. Binder
Mechanix Illustrated (Dec 1953)

By the mid-1950’s, the developed world had firmly entered the Atomic Age. It was a time characterized by great optimism on many fronts and the peaceful use of nuclear energy was just one of many new forms of technology that marked the beginning of a new era. At the same time, the 1945 bombings of Hiroshima and Nagasaki were a recent reminder of the destructive powers of nuclear technology, and the two major superpowers, now on opposite sides in a “cold war,” had entered into an arms race that saw the development of ever more potent weapons. 

The nuclear tests carried out by the United States at the site of the Bikini Atoll in the Marshall Islands began in 1946 and went on until 1958. The fact that a nuclear test site inspired the name for the new two-piece bathing suit released just days after the first bomb test says something about the predominently positive public attitudes at the time. French designer Louis Reard was clearly hoping that his contribution to the world of swimwear would be as explosive as the bomb. Public support – for the bomb, not the “bikini” – gradually waned and opposition grew, in particular following the fallout from the Castle Bravo test on March 1, 1954. The hydrogen bomb used in the test remains the most powerful nuclear device ever deployed by the United States. With its fifteen megatons of explosive power, the yield was more than twice as large as what had been initially expected. The harm caused by the explosion turned what would otherwise have remained a secret test into an international incident. The people living on nearby islands came down with radiation sickness, as did the crew of the Japanese fishing boat Daigo Fukuryu Maru. 

The year 1954 was also the year that the cult classic Them! went up in theaters, becoming the first major movie of the new monster genre. Them! sees an intrepid team of scientists and police officers go up against a new threat borne by the atomic test bombing in the New Mexico desert which preceded the attack on Japan. Following exposure to ionizing radiation, an ordinary ant colony is discovered to have undergone changes to its genetic code and grown to a terrifying size. 

The term mutation, which comes from the Latin verb mutare, literally means “to change,” and it is clear that the mutagenic properties of radiation, which at this time had entered into public consciousness, not only provided the foundation for Them!, and all the other similar movies that would follow in its wake (notably Godzilla, later that year), but also gave comic book creators the inspiration for a new kind of superhero, as well as a few monsters and villains.

Radiation Makes Superheroes

When the first issue of Daredevil was published a decade later, in February of 1964, Matt Murdock’s chance encounter with radiation was just a variation on what had become a familiar theme. Whether dramatic mutations followed a bite by a radioactive spider (The Amazing Spider-Man), exposure to cosmic rays (The Fantastic Four) or high levels of gamma radiation (The Incredible Hulk), there seemed to be no limit to just how dramatic the changes could be. 

In the real world, high doses of radiation very rarely do much good – the exception being certain therapeutic uses – and are more likely to kill anyone exposed than give her special powers. Even when radiation is used in the attempt to shrink the size of a tumor, it’s the very fact that radiation is harmful that is its main selling point, as radiation tends to be even less tolerated by rapidly dividing cancer cells, than it is by healthy tissue. 

I suspect that at least some of the appeal of radiation to writers of science fiction and horror stories is its insidious nature. It is difficult to miss a bomb blast, nuclear or otherwise, but it’s quite possible to be exposed to deadly levels of ionizing radiation without noticing it until the effects become apparent, hours or days after the initial exposure. At this point, it may be too late to do anything to halt or reverse the harm. 

Of course, according to the writers of superhero comics, radiation can have all kinds of interesting side effects, even beyond bestowing people with superpowers. We see a rather humorous example of this in Daredevil #43. In this issue, Matt Murdock is out on patrol as Daredevil when he is alerted to the theft of a medical bag containing “radioactive vials.” Apparently able to track the radiation – “with my hyper-keen senses, I’m like a walking Geiger counter!” – he experiences a burning sensation as he approaches his target and retrieves the bag. The burning gives way to dizziness and a strange feeling, and Daredevil realizes that his blinding accident must have made him hyper-sensitive to radiation! 

As it turns out, this second exposure makes him paranoid and excessively aggressive, and he spends the rest of the issue at the Madison Square Garden battling it out with Captain America who is putting on stage fights for charity. Only in comics…

But what exactly is this stuff of sci-fi magic? Though we often shorten the term to the more generic “radiation” to refer to the nasty stuff that gave rise to those three-eyed fish outside Mr. Burns’ Springfield power plant on The Simpson’s, what is usually meant is ionizing radiation. “Radiation,” if we are being technical, could refer to any propagation of energy in the form of particles or waves, including visible light. However, the photons emitted by a light bulb don’t have enough energy to interact with the tissues of the human body in a way that knocks electrons out of position and leaves charged molecules – that is the ions in ionizing – in their wake. 

Gamma radiation, the kind that Bruce Banner was exposed to in The Incredible Hulk #1, also consists of photons, but ones that are much more energetic than anything we would normally encounter. Gamma radiation lies at the most extreme, high-energy end of the electromagnetic spectrum, and carries at least 50,000 times more energy than the equivalent number of photons of visible light. A photon of visible light and a photon of higher energy are not fundamentally different in any other way; the potency for harm lies entirely in the size of the “punch” it packs. 

Just above the visible range, we find ultraviolet light, which has more energy than visible light. As anyone who has ever experienced sunburn can attest to, ultraviolet radiation can cause harm to human tissue, though it doesn’t fully penetrate the skin. Ultraviolet light, then, is also a form of ionizing radiation, but much less potent than gamma radiation, or the X-rays which occupy the step just below gamma rays on the electromagnetic spectrum.

High-energy photons from the gamma and X-ray portions of the electromagnetic spectrum are common byproducts of nuclear reactions, such as the nuclear decay of certain radioactive isotopes. Such reactions also commonly give rise to ionizing particles that, unlike photons, have actual mass and have nothing to do with the electromagnetic spectrum. Most commonly, these are alpha particles and beta particles. An alpha particle consists of two protons and two neutrons and is essentially a helium atom, stripped of its two electrons, which means that it carries a positive charge. Beta particles are identical to electrons, and so carry a single negative charge. 

When the Fantastic Four went into space, they were assaulted by cosmic rays, which was noticed by everyone onboard the ship by the sound generated by the ship’s sensors. When one of the crew of four exclaims “But I don’t feel anything!”, Reed Richards replies: “Naturally! They’re only rays of light! You can’t feel ‘em… But they’ll affect you just the same!” 

Despite his scientific credentials, this panicked exchange shows that Dr. Richards had an outdated understanding of cosmic rays. And yes, it was outdated even back in 1961, when the issue in question first hit the stands. Though the term “ray” in “cosmic ray” suggests an electromagnetic agent, this is a misnomer. Back in 1925, when physicist and Nobel laureate Robert A. Millikan coined the term, it was believed that most of the radiation that was reaching us from space came from high-energy photons. To be sure, there is plenty of radiation of all kinds in space, including gamma rays and X-rays, but the cosmic rays that Millikan was actually referring to were later discovered to consist primarily of high-speed particles, not photons. Some of them are the alpha particles mentioned above, and some of them are positively charged nuclei of even heavier elements. Most of them, however, are protons – the positively charged elementary particles most commonly found in the nuclei of atoms. With protons, we can add another player to our arsenal of ionizing particles and photons.

Hulk Likes Gamma Rays

In the practice of harnessing nuclear energy to generate power for use by homes and industries, having to deal with the spent, but highly radioactive, fuel is obviously considered a necessary evil. The same is largely true in the case of nuclear weapons, in the sense that the fallout has to be considered more collateral than the end goal. In fact, the United States government tried to downplay the full impact of this new kind of weaponry as best it could in the months after World War II war. 

And, even with all of the lasting devastation of radiation, only about five percent of the energy of a nuclear explosion takes this form. Most of the energy is converted into the shockwave of the initial blast, and the generation of an incredible amount of heat. The later development of the thermonuclear “hydrogen bomb” further underscores that the point of these weapons is explosive power. Hydrogen bombs primarily make use of nuclear fusion (the merging of nuclei), and only use the nuclear fission (splitting of nuclei) that we associate with the first generation of atomic bombs, and nuclear energy reactors, as an ignition step to create a fusion chain reaction. It is the first step, and not the second, that makes these bombs “dirty.” 

In The Incredible Hulk #1, the project that Bruce Banner was working on was the development of a “gamma bomb.” The impression you get from reading the issue is that the entire purpose of the bomb was to spread ionizing radiation, at least in part to satisfy scientific curiosity. This stands in stark contrast to the real-world situation I’ve outlined above. As the test is about to commence, Banner comments to himself: “In a few seconds we will finally learn what happens when the powerful gamma rays are released!” 

Considering the interest in radiation evident during Marvel’s Silver Age, it’s not surprising that Stan Lee and Jack Kirby chose to make the bomb all about those enigmatic rays. However, it’s also quite chilling to consider that Bruce Banner would purposely seek to use nuclear energy, not primarily for its explosive power, but specifically for its potentially even more far-reaching side effects. As if the death and destruction resulting from the blast itself weren’t bad enough! 

That is not to say that no one in our own universe has ever thought of ways to make already terrifying nuclear devices even worse, and Stan Lee and others clearly took this to heart. In the early years of the Daredevil comic, there are at least two references to nuclear devices containing the element cobalt. The first is in Daredevil #9, which sees Matt Murdock travel to the fictional country of Lichtenbad, at Karen’s behest, to meet with world-famous eye specialist Dr. van Eyck. Matt himself is not particularly interested in the surgery, for reasons we touched on in the first chapter, but is intrigued when he meets Klaus Kruger, a former law school classmate and current ruler of Lichtenbad, who is visiting New York. When asked about how Dr. van Eyck ended up settling in the country, Kruger is caught in a lie noticeable only to Matt. 

Lichtenbad turns out to be a tyrannical slave state that is keeping the good doctor prisoner. Kruger is also armed with a bomb that, when detonated, will unleash a “radio-active cobalt cloud” threatening the whole world. Fortunately for planet Earth, van Eyck heroically sacrifices himself to turn off the nuclear device, after it has been activated by Kruger, and perishes from the radiation. (This was perhaps convenient for Matt, since van Eyck had also just discovered the truth about Matt being Daredevil.) The second time a “cobalt bomb” is referenced is in Daredevil #57 when it is revealed that the monstrous Death’s Head, who has been tormenting both Karen and Daredevil during their trip to Karen’s childhood home, is really Karen’s father Paxton Page. He is described as the inventor of the cobalt bomb, and we learn that the combined effects of over-work and cobalt radiation had gradually driven him mad. Paxton meets his demise at the end of the issue, and Matt then chooses her father’s funeral as the time to reveal to Karen that Daredevil and Matt Murdock are one and the same. (Really, Murdock?)

No one has ever created a “cobalt bomb” in real life, but such a device has been imagined (and investigated). In 1950, Hungarian-American physicist Leo Szilard theorized on a University of Chicago Round Table radio program that a sufficiently large thermonuclear device would be able to annihilate all of mankind, if it were “salted” with particular materials, such as cobalt. The radioactive isotope of cobalt is a gamma emitter with a halflife that is short enough to create a high amount of initial radiation, yet long enough to make it impractical for people to wait it out in caves, bunkers and the like. 

This cobalt bomb would have been functionally equivalent to what the Hulk’s creators probably imagined his gamma bomb to be. The concept of a cobalt bomb has also appeared elsewhere in popular culture, such as in the cult classic Dr. Strangelove, or: How I Learned to Stop Worrying and Love the Bomb and the James Bond movie Goldfinger, which both came out in 1964.

If we briefly go back to the very real bombings of Hiroshima and Nagasaki in August of 1945, it is doubtful that very many people realized the full extent of the harm the bomb would bring in the longer term, beyond the bomb blast itself. Scientists and others close to the project obviously knew that ionizing radiation was harmful, and that there would be radioactive fallout. However, this was the first time an atom bomb had been dropped over a city with living, breathing human beings. No one had ever seen anything of this magnitude before, and it would have been difficult to predict, with any precision, the full scope of the events that would follow in the wake of the initial destruction.

The very first person in history whose cause of death was officially recorded as radiation sickness was a Japanese stage actress, by the name of Midori Naka, who survived the bombing of Hiroshima and made it back to her native Tokyo. She quickly fell ill and showed all of the symptoms we now know to associate with the condition: Nausea, headache, stomach pain, and bloody diarrhea. Her hair fell out. She gradually weakened until she died a few days later. Her doctors had no way of saving her. While the kind of acute sickness associated with the atomic bombs had not previoulsy been encountered on this scale, Midori Naka was obviously not the first to fall ill and die of radiation. 

Aside from the other victims of the bomb, many of whom died before her but without the fame to make it into the history books, there is the chilling story of the young women who worked for the United States Radium Corporation during and after World War I. These so-called “radium girls” painted watch dials that would glow in the dark using paint laced with radium, and were instructed to put the brushes in their mouths to form a perfect point between dips into the paint bottles. They were told that the practice was perfectly safe, and had no idea that many of them were signing their own death sentences. 

Little by little, the radium, chemically similar to calcium, would be absorbed into the bones of its victims. By the time they started developing symptoms, many would discover that their days were numbered. The first known victim, Mollie Maggia who died in 1922, would live to see her teeth and jaws completely rot away, before the disease reached her jugular vein and ended her life through a massive hemorrhage at the age of 24. Many others would meet a similar fate or die from cancerous tumors.

Another very famous early case of death by radiation was socialite Eben Byers. As was the case with the “radium girls,” Byers fell ill from continuous exposure to radium over several years, as opposed to the high instantaneous dose that were seen following the atomic bombs. Byers would drink several bottles daily of a patent “medicine” called Radithor, described by its manufacturer as a cure for, among other things, dyspepsia, high blood pressure and impotence. 

Between the years of 1927, when he began taking Radithor, and 1931, about a year before his death, it is estimated that Byers ingested the equivalent of about three times the amount that would have proved lethal if he had taken it all at once. By the time Byers died in March of 1932, his bones were affected, along with his vital organs, and most of his jaw and parts of the skull had been removed in an attempt to halt the spread of the disease. 

One of the insidious effects of radium poisoning is that radium is not only radioactive in and of itself, but decays into other isotopes that are themselves radioactive. This means that, past a certain point, there is little to be gained by getting off the “medication” as the body will continue to be subjected to ever higher doses of radiation at rates that outpace its ability to heal and rid itself of the toxin. 

Exposure to radioactive substances can indeed be very dangerous, and it is probably a good thing that every one of our heroes had encounters with radiation that were, at least, fairly brief.

Of X-Rays And Fruit Flies

Ionizing radiation causes damage to live tissues at a molecular level. In the case of acute radiation poisoning, the body absorbs such a high dose that the damaged cells lose their ability to divide properly. When enough cells are damaged in this way, the systems that rely on this constant cycle of destruction and renewal begin to collapse. The most critical are the blood cells, red blood cells in particular, and the cells which line the inside of the stomach and the intestinal tract. When the extent of the damage overwhelms the body’s ability to recover, death is inevitable.

One common cellular target for ionizing radiation is, of course, the DNA molecule itself, which is what makes radiation a so-called “mutagen.” A mutagen is any agent capable of increasing the rate of mutation above normally expected levels. We have already alluded to the ways in which this happens. There is the direct route, by which high-energy particles or photons knock electrons out of position, like in a high-stakes game of pool, leaving behind a charged molecule (again, the ion in “ionizing”). 

The damage can also happen by indirect means when the radiation interacts with water molecules in the cell, creating highly reactive so-called free radicals. If you’ve heard about them before, it might have been in a commercial for some skin care product that promises to fight them. Free radicals also interrupt the proper functioning of the cell and can damage DNA. Fortunately, there are several ways for DNA to repair itself, and this is a normal and ongoing process in the cell. 

But if ionizing radiation is a mutagen, it should be able to give us mutants, right? Well, sort of. Radiation, and other mutagenic agents, are in fact used in laboratory settings to raise the mutation rates of various organisms. It would take science over thirty years from the discovery of radioactivity to finally reach the conclusion that ionizing radiation could be used to this end, though maybe not in the ways superhero comics suggest. The credit for this discovery goes to Hermann Joseph Muller, one of the true pioneers of the study of the genetics of Drosophila melanogaster, more commonly known as the fruit fly. 

Far from being just the unglamourous little creature hovering around the fruit bowl, the fruit fly has a long history as a so-called model organism for the study of genetics. The legendary “fly room” at Columbia University, with which Muller was associated, provided the setting for some of the most important contributions to the modern understanding of genetics. Muller’s doctoral advisor and head of the lab was none other than the legendary Thomas Hunt Morgan, who would receive the 1933 Nobel Prize in Physiology or Medicine “for his discoveries concerning the role played by the chromosome in heredity.” Muller himself would get the same recognition in 1946 “for the discovery of the production of mutations by means of X-ray irradiation” that he’d made almost twenty years earlier, in 1927. 

Prior to Muller’s discovery, every new and interesting gene variant found in Drosophila and other organisms had been discovered by stumbling upon it by chance.During the couple of decades leading up to Muller’s discovery, only some fifty or so identifiable gene variants had been discovered in Drosophila. When Muller finally tested X-rays at the correct dose – one low enough to no outright kill or sterilize every last fly, yet high enough to get the job done – and crossed the exposed flies with each other, the results were astonishing. In a single evening, he discovered new “mutants” in numbers that might have equaled ten years of work by the conventional means of the time.

If we turn back to the comics, Muller’s finding that X-rays can indeed create mutants still leaves us with one big problem: Mutations tend to happen by chance. For a new trait to be expressed, a single mutation in a random cell isn’t enough. None of Muller’s X-ray exposed flies transformed into “mutants”  before his eyes. The gene changes were only evident in the offspring, all obviously formed from a single fertilized embryo. This is how an induced mutation in a single germ cell (egg or sperm) finds itself affecting the blueprint for the whole fly. And even then, noteworthy mutations are rare. Beneficial mutations that actually improve the odds of survival in the species’ natural habitat are even more rare, as has been the case throughout evolutionary history.

For someone like Peter Parker to have even the faintest chance of developing a new trait, spider-like or not, the exact same genetic changes would have to take place in every single cell of the body, or at least the relevant tissue or body part. The concerted and highly precise changes that might give someone superpowers are, sadly, a statistical impossibility. This should hardly come as a surprise to anyone, as bona fide superpowers are notoriously difficult to come by in real life. 

Since the time of Silver Age comics, radiation has gradually lost its importance as a convenient source of superpowers. When Spider-Man received a new and improved origin for his debut in Marvel’s “Ultimate” universe, the spider that bit him no longer had anything to do with radiation, but was simply “genetically modified.” This actually leaves a bit of an opening for a process that might, at least in theory, be able to introduce new genetic material: gene therapy. 

After a few disastrous failures during its early years, gene therapy has now come a long way as an effective treatment of certain genetic conditions. The idea behind it is to introduce new genetic material in place of a faulty gene, so that the altered cells will start producing the healthy version of whatever protein the gene codes for. The real game changer has been a revolutionary new gene editing technology called CRISPR/Cas9. This technology opens the door to much more precise therapies and has already been used to treat certain cancers, for instance. There is good reason to hope that certain genetic diseases could be cured by this method, though any technology this powerful of course also raises various ethical concerns for humanity to tackle going forward.

This most recent development has happened over the span of just a few years. Less than a decade after discovering the “gene scissors” used by Streptococcus bacteria to defend against viruses, and realizing their wider utility, Emmanuelle Charpentier and Jennifer Doudna were awarded the 2020 Nobel Prize in Chemistry. Blended with just the right amount of sci-fi fairy dust, this kind of technology, or something like it, is what I would pick for a more down to Earth retelling of Spider-Man’s origins.

In both the movie Daredevil (2003), and the more recent television show Marvel’s Daredevil (2015-2018), there is no reference to radiation being involved in young Matt’s accident, which further supports the move away from radiation. However, the “delivery mechanism” of getting weird gunk unceremoniously splattered in one’s face unfortunately doesn’t lend itself to an explanation involving sophisticated gene editing either. 

Keeping the details a bit vague when it comes to what exactly gave Matt his heightened senses is probably a wise creative decision. Trying too hard to explain the unexplainable risks the viewers’ ability to suspend disbelief, without really making them any wiser. Still, if we were to go along with the idea that parts of Matt’s body were somehow mutated as a result of his accident, there are definitely a handful of genes that would make for interesting targets. 

On the level of the senses, I would look at the family of genes that code for the olfactory receptor proteins. Members of this highly diverse repertoir of proteins bind to the odorant molecules that come in to the nose in a sort of lock and key fashion, with each particular olfactory receptor protein being activated by only a small subset of molecules. When we look at the human genome, and do some genetic archeology, we find that there are a lot of non-functional vestiges of olfactory receptor genes that were active in our ancestors but no longer code for anything. These kinds of gene “fossils” are called pseudo-genes, and the family of olfactory receptor genes in our own species includes quite a lot of them. While the human animal has a much better sense of smell than conventional wisdom would have us believe – much more on this later –we could still speculate that using comic book sci-fi to raise some of these pseudo-genes from the dead would allow Matt Murdock to smell certain compounds that are currently undetectable to us, or perhaps only detectable at high concentrations. 

Mutants And Superheroes

But if can safely conclude that radiation cannot give anyone superpowers, what about some of the other options that have traditionally been offered to us by superhero comics? We won’t have to look far to find one well-known example that offers a slightly different twist on the superhero origin story. 

The X-men were introduced in 1963, around the same time as many of the other classic Marvel characters, but they didn’t get their powers from anything that happened to them. They were born with their powers, even though tradition has it that the powers usually manifested around puberty. And, on the scale from “never, ever going to happen” to “it sort of makes sense in theory,” imagining that someone might be born with certain unusual abilities lies closer to the latter. 

If we widen the definition of “superpowered” in this case to include anyone born with a relatively neutral, though striking, physical difference – as is the case for some of the more obscure mutants from the comics – then clearly there are real people who owe their physical difference to an alteration of a single gene. 

Have you heard stories of people born with a tail? It’s exceedingly rare, but it does happen. The same goes for people with extra fingers or toes – or nipples, for that matter. When getting a back X-ray years ago, yours truly was found to have a tiny, vestigial “extra” lumbar rib, also known as a “gorilla rib.” They appear in about one percent of all people. I derive neither powers nor any ill effects from this innocuous bone growth, though I do appreciate being reminded of my evolutionary past. 

Traits that appear to hail back to an earlier ancestor are called atavisms, and appear throughout the animal kingdom in the form of hind limbs in whales, limbs in snakes, and teeth in chickens. If you have never seen a picture of a toothed chicken, I suggest you look one up. They look truly frightening! (And, how is that for proof that the dinosaurs never truly went away?) 

Some of our fictional mutant friends have traits that, if we are being exceedingly  generous, might be described as atavistic as well. There is Beast and his apelike features, and Angel with his bird wings. Although, to be clear, while humans share a common ancestor with birds, no species in our own lineage actually had wings. Obviously, Angel would be a bigger stretch of the imagination than Beast, but comic book magic might afford us some slack. 

Other relatively common genetic conditions can also drastically alter a person’s appearance. Albinism, which disrupts the normal production of the skin pigment melanin, occurs in people of all backgrounds, but is particularly common in certain parts of central Africa, where affected individuals are naturally prone to stand out, and be at great risk of harm from the sun. In the Marvel universe, we find the C-list mutant John “Jazz” Zander, whose only “power” is his blue skin. Aside from the obvious fact that albinism is a real condition, while being born with the skin tone of a smurf is not, the general idea that someone might be born looking strikingly different from other members of her community, due to a mutation, is considerably less of a stretch than the idea that gamma rays make you green and mean. 

The point is this: Excluding those mutants with powers that clearly defy the laws of physics and biology – such as  “phasing” through walls, spontaneous teleportation, or shooting energy blasts through any orifice of the body – it’s easy to see at least some parallells between real “mutants” and their fictional counterparts. And, the theme of social exclusion that often comes up in the X-Men comics probably also ring through for anyone who finds herself an outsider among her peers, for whatever reason.

Before the advent of modern genetics, people had no way of knowing that the subtle variation between individuals, whether they be humans, animals or plants, and the occiasional appearance of something strikingly out of the ordinary all had a common cause, and were not fundamentally separate phenomena. 

In fact, the existence of “sports,” as was one common name for individual specimens which appeared highly unusual, caused quite a debate between Charles Darwin and his cousin Francis Galton over the progression of evolution. To Galton, these “sports” showed that evolution can and does happen by leaps and bounds, challenging Darwin’s notion that the stepwise changes by which evolution happened were minute and gradual. As we now know, they were both right. The difference between the appearance of a “sport” and incremental changes in the outward appearance of a group of organisms are both manifestations of the same underlying process and depend entirely on where in the genetic code the mutation occurs. 

The average person carries approximately 70 spontaneous de novo mutations in their DNA, though this can vary quite a lot from person to person, and depends mostly on the age of the father at the time of conception. The term “de novo” is Latin for “of new” and means that these mutations have occured in the sperm or egg of the parents, and where not passed down to them from their parents. In this sense, I suppose we are all mutants. However, most of these changes don’t really matter. They are either completely neutral, appear in a region of DNA that doesn’t code for anything (what is usually called “junk DNA”) or impact the function of whatever the affected gene codes for to such a limited degree that it is not readily apparent that anything is amiss. Only rarely do we see changes that cause obvious disease or impairment. Of course, it is also the case that many pregnancies are lost very early due to mutations in the embryo that are incompatible with life.

For a look at one condition out of many that frequently stems from a de novo mution, there is the example of achondroplasia, the most common form of dwarfism. Achondroplasia shows a dominant pattern of inheritance, in that one copy of the faulty gene is enough for the expression of the typical traits. This also means that people with achondroplasia then have a fifty-fifty change of passing on the condition to their children. However, as many as 80 percent of people with achondroplasia have two unaffected parents of average height, meaning that we are dealing with a “new” mutation in the majority of cases. 

If we are to believe comic book canon, Marvel’s mutants have generally appeared as the first of their kind in their families as well, and much is made of the resulting tension between parent and mutant child in, for instance, the first X-men movies. “Have you tried not being a mutant?” is a memorable line from the movie X2 (2003), when a young Bobby “Iceman” Drake essentially “comes out” to his parent.

According to Marvel lore, all mutants share a piece of underlying genetic hardware in the shape of the mysterious “X-gene,” although it’s not quite clear whether this constitutes a particular change to a gene common to all humans or whether we are talking about an entirely new piece of code. 

In Astonishing X-Men #25 (2008), Hank McCoy, aka Beast, offers the following description: “The X-gene always sits on chromosome 23, and uses an exotic protein to send chemical signals to the other genes, which mutates them.” Humans typically have 22 pairs of so-called autosomes, or chromosomes that are not involved in sex differentiation, and one pair of sex chromosome which constitutes the 23rd pair. Hank doesn’t specify that the X-gene is on the X-chromosome, but since that is the only one from the “23rd pair” that is present in both males and females, it is the only reasonable candidate. May we even assume that its designation as the X-chromosome was what inspired the connection to the X-gene in the first place? Whatever the case may be, we know that this gene has to code for something really interesting. According to the information above, the X-gene is either a stretch of DNA that serves as a binding site for, or modulator of, the “exotic protein” in question, or it simply contains the instructions for making this protein. The latter sounds more plausible.

But how can the very same gene manifest itself in so many different ways? Well, it cannot. At least not to the extent that we see in the comics. And, again, it is probably best that I reiterate that the vast majority of mutations among the mutants of the Marvel Universe represent real-life impossibilites for any number of reasons. However, that is not to say that context doesn’t matter in genetics, because it certainly does. 

The same genetic mutation in two different people may not manifest itself in the exact same way or to the same degree. This is particularly true for complex so-called polygenic traits that are governed by the interplay of any number of genes that each add one piece to the overall picture. 

A more dramatic example of how the behavior of genes changes depending on context has to do with how their pattern of expression is governed by the presence of molecular “on” and “off” switches. Not too long ago, it was assumed that everything you needed to know about the phenotype of an organism – that is the physical manifestation of its genetic material – could be traced back in its entirety to the genetic code, and only the genetic code. We now know that there is another layer of information acting on top of – or in addition to – the sequence of “letters” that make up our genome. This added layer of information affects how and when the genes are expressed. The study of this phenomenon is known as epigenetics.

The impact of epigenetics can be striking. Two conditions known as Angelman syndrome and Prader-Willi syndrome involve the same deletion of a small section of chromosome 15. Which of the two syndromes develop – and they really are quite different – depends entirely on whether the faulty chromosome came from the mother or the father. This is becuase the epigenetic “imprint” of the chromosome will mark its parental origin and affect the pattern of expression of other genes near the one that is missing. 

If you’re going to find one process that would allow the same gene, such as the mythical X-gene, to express itself very differently from one person to the next, some kind of epigentic process is probably a must. Perhaps the X-gene, as Hank McCoy’s description suggests, is a master modulator gene that codes for some kind of molecular signal that acts randomly on other genetic targets? It may not even need to “mutate” them, but simply act to supress or activate them. To our knowledge, no such gene exists, but I say it is good enough for comic book science, even though existing in-story descriptions are lacking in detail and a deeper understanding of genetics.

Before leaving the topic of epigenetics, it is worth noting that it has also been demonstrated to factor into neural development, as well as ongoing dynamic changes in the brain related to memory and learning.


At the end of the day, it’s important to recognize that, despite my attempts to suggest avenues that might theoretically bestow someone with “superpowers,” it still takes quite a bit of comic book magic to actually get there. Any meaningful discussion of the science of modern superheroes and their powers requires that we move past the point of origin, the “miracle exception” I mentioned in the book’s introduction, and accept that certain things just are what they are. 

Any explanation of how young Matt Murdock would have been bestowed with dramatically heightened senses falls into the realm of the supernatural, just as no amount of sci-fi level genetics will really give mutant Kitty Pryde the ability to phase through walls. But, we are about to step onto more solid ground. With our heightened senses in place, let us tackle the questions of what the nature of such endowments might look like, and what someone like Matt Murdock could do with them.