The Genetics Needed to Make X-Men
By Kyle Hill on May 23, 2014
Changes to your genome make you a mutant, but telepathy, diamond skin, and bone claws make you one of the X-Men.
Evolution drives the diversity of all life on Earth. From microbes to macaws, random mutation and natural selection have come up with fantastic, jury-rigged solutions to life’s myriad problems. Over millions of years and thousands of generations, ancestors of dinosaurs can become birds, and ancestors of apes can become humans. Evolution may be slow and ultimately undirected, but there’s no denying that it is incredibly powerful.
It’s no wonder then that science fiction has used evolution to craft some of its most famous characters. If natural processes could take a digestive enzyme in snakes and turn it into a neurotoxin, why not fantasize about evolution making an Ice Man or Wolverine?
We are all mutants. You probably won’t wake up with Angel’s wings, but at your birth and during your life your DNA mutates. Most of the time, these changes are harmless or even harmful. A mutation in the BRCA 1 and BRCA 2 genes, for example, dramatically increases the risk of breast cancer in women. But every once in a while, a genetic mutation can produce something worthy of Xavier’s School for Gifted Youngsters.
From the comics and the movies we know that the mutants of the series are humans who express the “X-gene”. Random mutations in their genetic code unlocked this dormant gene, and its expression produces the powers we see via proteins. Turning into a mutant, as Erik Lehnsherr did while at Nazi concentration camps for example, is like the scientific field of epigenetics—the study of how environmental factors like stress influence gene expression.
The power of expressing “dormant genes” isn’t science fiction either, as some chicken embryos can attest. In 2006, researchers investigating the development of chickens discovered that a mutation in one gene caused the embryos to sprout teeth. Scientists already knew that birds lost their teeth around 80 million years ago, so the experiments seemed to indicate that this gene was turned off long ago. After it mutated, teeth returned.
But genomes are not the super power switchboards they seem. While it’s true that turning one gene on or off can have huge consequences, much of our genetics is a tangled mess of interactions involving dozens or hundreds of genes simultaneously. In X-Men lore, the X-gene makes a protein that in turn produces chemical signals throughout the body, inducing mutations on other genes. Becoming a mutant is the result of a radical chemical cascade.
Genetic mutations aren’t the same every human, and especially for every mutant. Dr. Jean Grey, or Phoenix, is a very powerful, very rare mutant. We observe this in nature—larger effects are rare. That’s why evolution takes a long time and new characteristics don’t just spring up.
Going from run-of-the-mill mutants like us to full-fledged X-Men may not be all Hollywood flair. Late last year, researchers uncovered a gene that could potentially allow us to regrow limbs like salamanders or starfish. Salamanders, for example, can fully regrow limbs, eyes, and even parts of their brains. We might have the same ability, but along our evolutionary path something was turned off. Call this research the hunt for the Wolverine gene.
So, how far away are we from being X-Men? How would the next step in human evolution happen?
X-Men Origins: Human
The fundamental tension in the X-Men universe is between humans and mutants, as though Professor X constituted a different, dangerous new species. Indeed, the movies go to great lengths to make you understand that mutants are a new species and “the next evolution” of humans.
Evolution works by naturally selecting random mutations that occur within an organism’s DNA. And when DNA is copying inside a yet-to-be-born organism, a few mistakes are made. These mistakes usually do nothing or are harmful, but sometimes they help the organism. When a proto-giraffe is born with a slightly longer neck—and can therefore out-compete other giraffes for food and reproduce more—those genetics that produced the long neck get passed on more often. If these genetics make it through enough of the population over enough time, the trait starts dominating in that population. Eventually, proto-giraffes become the long-necked beauties we see today.
With enough genetic changes, new species emerge. A lot of the time it’s through natural selection, but random “genetic drift” and even geographic isolation can make new species. Fire-flinging and mind control are indeed huge genetic changes, so what else would the X-Men need to be biologically classified as the new species “homo superior”?
As shown in X-Men: The Last Stand, the mutant X-gene can be fully suppressed, rendering any mutant fully human again. This means that the X-gene is probably only producing a few proteins that induce mutant powers, and that a few antibodies can eliminate those powers. “Homo superior” would need to evolve to the point where the mutations were so interwoven they could not be successfully separated.
Next, the X-Men would have to stop having sex with regular humans. One way of distinguishing species from each other is whether or not they can interbreed and produce fertile offspring. If two representative organisms can’t, they are probably different species. For example, a lion and a tiger can produce a liger, which might seem like a new species, but the liger itself cannot reproduce. That’s a good indication that lions and tigers are indeed different species. If X-Men stopping interbreeding with humans, genetics rifts could get deep enough that re-combining the “races” would be impossible.
Lastly, X-Men super powers would have to get less varied. Biologically distinct species have phenotypes, or definable sets of physical characteristics that all those individuals of the species share. X-Men don’t yet have strict phenotypes—they seem as different from each other as they are from humans.
Who knows what dormant powers are hidden in our genome. The mutations we already know of can indeed be incredible. Some children are born with a mutation that inhibits the feeling of pain, and others have myostatin-related muscle hypertrophy—a genetic mutation that doubles skeletal muscle. And human are taking the next step in evolving all the time. The ability to digest proteins found in animal milk was a mutation that spread to many human populations just a few thousand years ago. So is having blue eyes.
Given enough time, the next step could be more towards Wolverine or Mystique than we think.
Kyle Hill is the Science Officer of the Nerdist enterprise. Follow the science on Twitter @Sci_Phile.