Thomas Mailund, a bioinformatician from the Aarhus University of Denmark, once proposed that humans in the future could evolve to be smaller because of our bodily functions having fewer physical activities. He suggested that the shrunken size of the human being would also be useful in a world that is densely populated.
Then there is the concept of designer babies. Even though this practice is controversial and no one can predict the outcomes, scientists have already developed the technology necessary to alter the DNA of an embryo. It is known as CRISPR-Cas9.
While these are interesting thought experiments, we obviously don't know the future. Billions of years of evolution have made us what we are today. And unbeknownst to us, evolution is still ongoing; probably far speedier than ever before.
But one wonders: what does the future really hold for homo sapiens? How will we evolve over the next few centuries? What kind of changes will there be, both physio and neurological? And to what extent? Or what will we look like in a few thousand (or millions) years, assuming that we are not wiped out from the face of the earth due to climate change, nuclear armageddon or an asteroid colliding with earth like the ones that led to the extinction of the dinosaurs.
What we are today, took billions of years of evolutionary progress. Being a present-day homo sapien is not the end of the story either. Human beings have developed the capability to intervene and influence their own destiny.
Until a certain point in our history, the homo sapiens and its cousins in homo Erectus, the neanderthals and other hominids had only been subjected to natural evolution, that is, evolution by natural selection.
Since then, human civilisation - for better or worse - has come a long way and has reached the pinnacle of technological progress; so much so that now we can artificially accelerate this rate of change, edit faulty genes to cure rare genetic diseases and potentially save hundreds of thousands of lives. While nature selected the best option through mutations over thousands of generations, now we can achieve that through our own technology.
To be truthful, the purpose of the story is not to judge the forward path of natural evolution but rather what the human being will look like in the future as a result of all the scientific innovations such as gene editing, brain implants, artificial organ transplants etc.
Just like science fiction novels and movies, our posterity might transform into cyborgs – half human and half machine – with machine chips and implants, eyes supplemented with high-tech cameras and even the ability to regenerate limbs and other organs.
Biotech advancements have the potential to merge with human physiology. Perhaps we might alter our size, our shape, our weight, our skin tone, and even our features.
The topic of the future of sapiens has recently been most popularised by Yuval Noah Harari, author of three books on the state of humankind: Sapiens, Homo Deus and 21 lessons for the 21st century. For example, he famously said, "Homo sapiens as we know them will disappear in a century or so".
His book "Homo Deus: A Brief History of Tomorrow" in particular examines the possible impact of biotechnological and artificial intelligence innovation on Homo sapiens, heralding perhaps the beginning of a new bionic or semi-computerised form of humans.
In an interview with BBC, he said in a reference to improving the human brain's memory capacity, "An implant in the brain would allow us to remember people's names, for example. We know what genes are involved in building a brain that's good at remembering people's names. We might just change that. It sounds more like science fiction. But we can do that right now. We can implant it but we don't know how to wire it up to make it useful. We're getting there but it's very experimental."
He added that the future trajectory of humanity is not just "biological" anymore but more and more "technological".
Many people now have implants to repair parts of their bodies that are damaged, for instance, a pacemaker. These implants are becoming more common.
In addition to having chips implanted in our brains, we may also have the technology that is more obviously a part of our countenance. For example, we may have an artificial eye that is equipped with a camera that can scan various colour frequencies and pictures, adding new dimensions to our sensory inputs.
Directed evolution, in which humans intentionally shape the course of their own species' evolutionary history, is one of the most extreme ideas.
However, experts speculate that in the not-too-distant future, it would be considered immoral to not alter specific genes. Because of this, parents may be able to choose the physical characteristics of their children, leading to the possibility that future generations of humans will look the way their parents see them.
"Predicting out a million years is pure speculation, but predicting into the more immediate future is certainly possible using bioinformatics by combining what is known about genetic variation now with models of demographic change going forward," says Dr Jason A. Hodgson, Lecturer, Grand Challenges in Ecosystems and the Environment.
We don't know, but, certainly, human genetic variation is increasing. Worldwide there are roughly two new mutations for every one of the 3.5 billion base pairs in the human genome every year, says Hodgson. Which is pretty amazing - and makes it unlikely we will look the same in the years to come.
Current technologies on human enhancement
Many different forms of human enhancing technologies are either on the way or are currently being tested and trialed. Some of the fields involve 3D bioprinting, genome editing, artificial organ implants, biohacking, cloning etc. However, here three fields with that are being currently in developed discussed:
Human genetic engineering refers to human enhancement by means of a genetic modification. This could be done in order to cure diseases (gene therapy), prevent the possibility of getting a particular disease, to improve athlete performance in sporting events (gene doping), or to change physical appearance, metabolism, and even improve physical capabilities and mental faculties such as memory and intelligence.
Neurotechnology encompasses any method or electronic device which interfaces with the nervous system to monitor neural activity. Currently, modern science can image nearly all aspects of the brain as well as control a degree of the function of the brain. It can help control depression, over-activation, sleep deprivation, and many other conditions.
Artificial organ implants
An artificial organ is a human-made organ device or tissue that is implanted into a human to replace a natural organ. It is also possible to construct and install an artificial organ to give its possessor abilities that are not naturally occurring. Research is proceeding in areas of vision, memory, and information processing. Some current research focuses on constructing artificial limbs, lungs, kidneys, hearts and even the brain.