If you were to compare, say, a human and a fish, there’s very little on the surface they seem to have in common. The truth, however, is that every living creature on Earth shares a common ancestor.
At our very core, humans are related to everything from insects to whales. This has another very important implication – all life uses a common genetic code. At the core of every living creature there are genes. Genes are contained in DNA or RNA. These are molecules that contain a chemical code which describes how to build the organism in question.
For example, in humans it’s one or more genes that determine your hair color, build, and just about everything else about you. Even non-genetic factors that shape you have to interact with your genes for the final result. So two people may both be overweight due to poor diet or low activity, but one could be more genetically predisposed to become diabetic.
Engineering by Degrees
If you take a piece of DNA and alter its genetic code, you will change the organism that is eventually formed. That’s a potentially world-changing event since so much of what’s wrong with humanity can be traced back to their genes. There is a whole host of genetic diseases that lead to a lot of pain and misery in the world. Just eliminating the genes that make cancer or heart disease more likely could make the world a better place on a profound level.
Directly manipulating genes is referred to as the science of genetic engineering. It may seem like something rather futuristic, but direct gene-editing has been a practical science for decades.
Before genetic engineering, humans had deliberately changed genes in more indirect ways. That’s how we got domestic dogs from the wolf, and just about every edible crop. If you’ve ever seen what wild bananas or wild corn looks like, you’ll appreciate what thousands of years of selective breeding can do. Genetic engineering takes the tedium, slowness, and most of the uncertainty out of the process. You go straight for the genes you want to alter and then check that you get the right results.
Many Ways to Engineer an Embryo
One immediate question is, of course, where do you get the new code? There are a couple of ways that you can change genes. One way is to simply switch undesirable genes off. This means you don’t add anything to the code, but deactivate or even cut out parts of it. Alternatively, you can go to another organism, whether from the same species or not, and copy the desired genes to your target organism.
One famous example might be if scientists took the genes that tell a spider’s body how to produce it’s remarkable silk, and spliced them into another animal, making it easier to farm the material in bulk. So now we have domesticated goats that have those spider genes in them, producing spider silk in their milk. The genes come from the golden orb-weaving spider, which is generally not considered the most domesticated of animals.
There are other examples as well, such as in the food we eat. Genetically Modified Foods are everywhere and have done a lot to ease world hunger. GMO maize that’s resistant to various threats, such as insects, have been a safe staple for many years.
Of course, many people have an instinctive aversion to the idea of putting spider genes in goats, but there’s nothing inherently ‘spidery’ or ‘goaty’ about genes. It’s just code, not something that will inadvertently result in eight-legged goats.
Apart from deleting or copy-pasting genes, there’s now a third option: write your own. Scientist Craig Venter stunned the world back in 2010 when he and his team produced the first-ever living organism that did NOT share an ancestor with any other organism on earth. He created a single-celled organism with a genetic code created from scratch and assembled into DNA. This has sparked a synthetic genetics industry and added another important tool in the future of genetics.
You can’t go far in a discussion of human genetic engineering without hitting upon the topic of “designer babies”. The idea is that you specify the traits that you want in your offspring. Do you want children who are tall? Perhaps one who is going to be fit, with a fast metabolism? Blonde hair? Blue eyes? In principle, it may one day all be possible.
For a lot of people this represents a rather slippery slope. You start off by doing things that few people would argue against – curing genetic disorders in the womb. Once you’ve done that, why not fiddle about with the genes some more? A lot of this fear comes from a place of insecurity. We read a lot about how we’ll be made irrelevant with the rise of AI and superior artificial life, but a generation of super-intelligent Olympic gods will do the job just as well.
There’s also the question of parentage. If you extensively modify your offspring, are they really your children at all? And then there is also a very real worry that since most people would like the same positive traits, humans will be much less diverse – a problem on multiple levels. We’re not there yet, but the time when we’ll have to make these choices for real is pretty close.
If we can splice genes from different species into each other, why not into humans? Of course this is entirely possible. Just as with our spider-goats you could put genes into human embryos that would transfer certain traits to the offspring. Night vision? A dog’s sense of smell? Muscles like a gorilla? The potential is there to really go beyond the abilities of natural human beings.
Of course, it’s not so simple as to just paste in gorilla and eagle genes. Genes form a complex system of interactions. This means that changing one thing can have a knock-on effect down the line. While trial-and-error may pass ethical muster with animal research, there’s a big red stop sign when it comes to human experimentation.
Doing it the other way around hasn’t had as many roadblocks. Specifically, there is practical research going on to splice human genes into animals. For example, by splicing human genes into pigs, scientists hope to grow transplantable human organs inside the pigs that can then be used to save human lives. The big worry is that these animals will become ‘too human’ and cause a whole host of new ethical problems.
Although this particular story got a lot of attention, we’ve been using animals such as mice with human genes spliced in for some time now. In general, the potential benefits strongly outweigh any envisioned harm, so researchers will push forward until they have a good reason not to.
Not every nation is so ethically adverse to modifying humans either. For example, Chinese scientists have been modifying human embryos in an attempt to build HIV resistance directly at the genetic level. The eggs they used were inviable, which meant most ethical qualms in the international community were quashed, but this is still a very hot potato indeed.
Another interesting area of human modification research is that of cybernetics, which is the creation and installation of artificial components to a living creature. Technically, if you wear glasses or contacts, you are a cyborg, but popular culture reserves the term for the likes of RoboCop or the Terminator.
As I’ve explained in my article on Brain-Computer Interfaces (BCIs) humanity is making great strides in radical cybernetics, but the job would be a lot less complicated if the human body was more amenable to the devices we want to implant in it.
Genetic modification could hold the key to more easily meld man and machine. Genes could be modified to grow the right sort of nerve receptors or help the body accept certain foreign materials. Perhaps the genes that control brain development could be used to modify the brain so that it’s ready for things like exocortices or microchips.
Making a Martian
The 20th century marks the first time we human have ever left our birth planet and stepped foot on another world. That world was, of course, the moon. Now it seems that we will step foot on planets further out in the solar system, maybe in as early as the 2020s.
The first planet is Mars, one which we have already visited using our robotic probes. We know quite a lot about the red planet, which has fascinated us for centuries. Mars is interesting because it’s so close to Earth in its makeup. Some think that Earth and Mars were much more similar, but that some sort of catastrophic event produced the lifeless Martian world we know today. It’s tempting to focus on Mars because of a concept known as terraforming, which is a massive engineering process of converting a planet into something that can support human life unaided. Right now, no human could survive more than a few seconds on the Martian surface without dying a rather painful death.
The problem is that even if theoretical models of terraforming work, it can take hundreds or thousands of years before humans could even think of going outside on Mars in nothing but their skin. So why not meet the terraformers halfway? We could use genetic engineering to adapt human being to life on a Mars more friendly than it is now, though not quite as friendly as Earth.
The Long Haul
Genetic engineering may also be a way to adapt humans for life in space. Microgravity and other conditions in space have a multitude of negative effects on a body adapted for our 1G of gravitational force. It may also be possible to allow for hibernation or other ways to make interstellar flight possible within a single generation. Really, there are lots of ways genetic engineering could help humankind’s expansion into space.
Do We Have the Guts?
Humans have been messing with genes in other animals for thousands of years. That little yapping dog your neighbor insists on taking everywhere is actually just a modified wolf brought about through selective breeding. Humans have never successfully practiced selective breeding on themselves. Ideas such as eugenics, where people with ‘undesirable’ traits have been prevented from reproducing, have been dismantled – and rightly so.
But it raises a lot of questions about how far humans will be willing to go with the technology of genetic engineering. In principle, the sky’s the limit, but if you step over some sort of line, presumably we’ll have different species of human descendant. We will be related to one another in the same way we’re related to gorillas and chimps.
The morality of this is debatable, since in one way we’d just be doing what nature would have done anyway. If any humans became genetically isolated from the main population (such as on a Martian colony), they’d eventually turn into a new species anyway.
There’s little doubt that we WILL genetically engineer ourselves, but whether we will do it to become something more or something different from today’s humans is entirely open.