What Does the Future Hold for You, Homo Sapiens?
Homo sapiens (Latin: wise man) entered the scene between 350,000 and 300,000 years ago in Africa as the latest finds in Morocco confirmed.
Human evolution did not follow a straight line with a succession of species, one replacing the other. For millions of years, Earth sustained numerous coexisting types of hominins. Homo sapiens coexisted with other Homo species until the only one species left - us - modern humans about 40,000 years ago.
Svante Pääbo, a Swedish evolutionary geneticist who decoded the Neanderthal genome has shown that Neanderthals and other extinct hominin species have made a significant contribution to the ancestry of modern humans. He and his team discovered genetic evidence of interbreeding between archaic humans (Neanderthals, Denisovans and other earlier forms of humans) and anatomically modern humans.
The latest research showed that the remnants of Neanderthal DNA survive in every human. Approximately 2% of their genome in the non-African population and a third of it in the African.
We can say that Neanderthals are not extinct. They live on in our DNA!
There is a lot we still do not know about our species and the complex process of the early formation of Homo sapiens. Scientists continue to fill in the gaps by studying DNA inside ancient bone fragments. DNA of every organism reveals its ancient evolutionary past. A cutting-edge technique called Next-Generation Sequencing helps to uncover new evidence and reassess old finds.
Many people reject evolution as an explanation for how humans and other organisms evolved and developed, despite extensive evidence. Misunderstanding of how life changed after its origin leads to many misconceptions about evolution regardless of how life started. Humans are not descended from monkeys, as the title picture may give the wrong impression (*) but we share a common ancestor that lived between 8 and 6 million years ago. Humans evolved differently from the same ancestor.
There is no doubt that evolution has both occurred and continues to occur. The vision of the future of human species is something that tickles my imagination. Is it possible to predict where evolution taking us? What comes after Homo sapiens?
Human Beings Are Still Evolving
Human DNA is constantly changing through the process of mutation. Genetic hereditary mutations are essential to evolution. In the last 40,000 years, the rate of evolutionary change of DNA has accelerated. Eight per cent of human genes have evolved as recently as 5,000 years ago. To illustrate, old Sumerians and Egyptians were different from us genetically.
Our species never stopped evolving.
A recent large-scale genetic study analysed the genomes of 210,000 people in the United States and Britain. Genetic evidence indicates that the mechanisms of evolution are still shaping our species. Scientists are now able to trace the evolutionary shifts of the human genome through one or two generations or in other words, directly observe ongoing selection in humans.
Adaptation to the changing environment is the powerful driving force behind biological change in humans. Thanks to technology and medical advances, the number of hazards (selection pressures) we experience in our lives has drastically reduced. Those that would not previously have survived to reproduce and contribute to the human gene pool now succeed. But making humans too dependent on medicine also leads to the increasing of genes that have little or no resistance to disease. In other words, we are no longer adapted to infectious diseases through natural selection.
However, there are still parts of the world where people have none or very little access to quality medical care. Survivors of deadly diseases such as Lassa fever and malaria drive natural selection by passing on their genetic resistance to offspring.
Technology and medicine might alter the human gene pool, but they do not take away the force of evolutionary change and its mechanisms. One of them is genetic drift, which in short is evolution due to chance events. It is also known as evolution by sampling error - evolution sometimes happens by pure chance.
As I see it, nature - our biology never stands still and will always "push" evolution. It is a slow and continuous process with no preconceived direction. It has no end and purpose.
Future Homo Sapiens
There is a high probability we will become intelligent designers of our species and start engineering super-humans.
Advances in genetic engineering have already opened up unimaginable possibilities. In the future, we might be able making alterations to our immune system and life expectancy but also improve our intellectual capacities.
We might go even further and create cyborgs.
Real-life cyborgs already exist! Neil Harbisson is the world first legally recognized cyborg. He is born with achromatopsia, a form of extreme colour blindness that limits him to seeing in only black and white. An antenna, a cybernetic enhancement to his biological self, is permanently implanted in his skull and gives him the ability to perceive colours as sound.
Jim Ewing is the first cyborg rock climber who lost his lower leg in a climbing accident. He has a brain-controlled bionic limb that enabled him to climb again.
Bionic limbs, which operate through brain impulses have revolutionized prosthetics. It allows a person to control the movement of a prosthetic, simply by thinking of commands. In the image below, Claudia Mitchell, the first woman to receive a bionic arm, uses her new prosthetic arm to “high five” with the first bionic arm recipient Jesse Sullivan.
In the future, technology might be used not just to overcome disabilities, but also to upgrade human abilities forming a symbiotic relationship between humans and machines. Technologies implanted inside us will obfuscate the distinction between human and machine. Machines will not just help us do or think but have the potential to help us be. The line between humans and machines will become blurred.
These predictions are very disturbing. The question is, how much of us can be symbiotically transformed while we are still considered human beings?
Predictions go even further.
Genetic engineering will lead to a new dominant species that some scientists called alien children - designed babies born with the planned set of genes. The powerful gene-editing tool, CRISPR, is already employed to modify human embryos. CRISPR/CAS9 technique enables altering DNA sequences and modifying gene function.
So far, three "CRISPR babies" are born, all of them in China.
Despite calling for a global moratorium on human germline editing and changing the heritable DNA to make genetically modified children, it is impossible to control the use of CRISPR technology. It is inevitable that in the next 100 years, numerous embryos editing for desirable traits will be implanted.
In a not so distant future, gene-editing technology could affect nature at an unprecedented level. A nightmarish vision of the future would be to allow ill-intended people to redesign nature to meet their needs.
Still, technology such as CRISPR does not bypass the evolution process. Life is just too complex for that.
How Much Time Is Left for Homo Sapiens?
It has been estimated that 99.9% of all species that ever existed on Earth are extinct. In roughly 5 billion years, the Sun will start turning into a red giant star and expand out to the Earth orbit. Our planet might survive, but the most recent simulations suggest that the dying Sun will eventually swallow Earth.
Humans are very likely to disappear from this planet long before then. According to estimates, conditions to support life on Earth will last for between 1.5 and 2 billion years.
So how much time is left for humans?
What about using math to forecast the future of the human species. The over-simplistic mathematical argument for the prediction of the demise of our species already exists. The so-called doomsday calculation is also known as the Doomsday argument. It is a group of probabilistic arguments about the likely survival of humankind.
An early version of the Doomsday argument was introduced by the astrophysicist Brandon Carter (the Carter catastrophe) though he did not publish on Doomsday per se. In the early 1980s, Carter came up with the idea that human race is halfway to its extinction. The risk that our species will soon die out has been largely underestimated. We can try to compensate for this by taking greater care but according to Carter, Doom Soon is a more likely scenario than Doom Delayed.
Carter also coined the term anthropic principle as a contrast to the Copernican principle that states the Earth is not in a specially favoured position in the universe and we, as intelligent observers do not occupy a special place.
The anthropic principle or argument of fine-tuning expresses an intriguing thought that the physical characteristics of the universe are not only perfectly tuned for life, but the universe is the way it is precisely to enable carbon-based life. If the fundamental properties of the universe were any different, we would not be here and thus no conscious and sapient life to observe it.
Since Carter, the Doomsday argument was developed and popularized by Leslie, Nielsen, Gott and some others. In 1993, the Princeton University astrophysicist John Gott published a hypothesis about the total longevity of our species. It is a version of the Doomsday argument he called the ‘delta t’ argument, based on applying the Copernican principle to time.
Below is the Gott’s formula for predicting how long our species is going to last. As stated by Gott, the equation is applicable for making a wide range of predictions about almost everything.
The prediction about how long human race will last is based on how long it has been in existence so far (t past). Our species was thought to be roughly 200,000 years old. The latest finds in Morocco confirmed that Homo sapiens entered the scene between 350,000 and 300,000 years ago in Africa.
Taking the value of 200,000 for t past, Gott predicted with the 95% probability that the future longevity of our species is at least 5100 years but less than 7.8 million.
Needless to say, there were many refutations of the argument, rolling eyes and heated discussions in the scientific community. Author’s replies to numerous objections to the argument would easily fill a book. But over the years, the Doomsday argument has gained many proponents as well. Though being extremely controversial, it is a subject that still arouses a lot of interest.
Considering the doomsday math flawed or believing it is just a good philosophical puzzle, the Gott’s numbers are pretty in line with those for other extinct species of hominins and mammals. The actual evidence shows that the average survival time for mammalian species has been 2.33 million years. Homo erectus lasted about 2 million years, while Neanderthals lasted 300,000 years. One of the biggest dinosaurs that ever lived, Tyrannosaurus rex lasted 2.5 million years.
Predicting the future of complex systems is, to say the least, a difficult challenge because there are far too many variables to be predicted. Accurate scientific predictions about the evolution of Homo sapiens are impossible because of the various directions that human evolution might take.
Will Homo nouveau replace Homo sapiens as predicted by physician Don Simborg? Could technology or a global catastrophe induce this new species? Will Homo sapiens create Homo nouveau, and two Homo species coexist with one another?
We do not know the answers. As humans, we will continue to evolve and adapt, but the prospects of humanity are uncertain.
Who knows what our species and those that evolve from us will become and do here on Earth? And later, if humans migrate to other planets, outside our solar system.
But what are the chances of spreading across the universe?
The physicist Enrico Fermi posed a famous question: “If aliens exist, where are they all?” It is known as the Fermi paradox. One of the possible answers to that question is that intelligent life is self-destructed and destroys itself before it can spread.
The chances for asteroid impacts, super-volcanoes, natural disasters, pandemics and the like to wipe out all humans are extremely small.
We are the most dangerous threat to ourselves.
The odds on surviving another 5,120 years despite many global threats induced by human activities seems pretty good from the current perspective!
The fact that our species is capable of a long future does not mean this is probable. It may be something that has to be earned by being smarter, wiser, kinder, more careful — and luckier — than we’ve ever had to be before.
As the Copernican principle states, we are not significant species in the universe, who lives in a special place, at a special time. But even so, what an amazing species we are and what an incredible journey Homo sapiens had hitherto!
Let us hope we are smart and wise enough to protect ourselves from us.
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*Title Image: A display of a series of skeletons showing the evolution of humans at the Peabody Museum, New Haven, Connecticut, circa 1935 (Hulton Archive/Getty Images).
A linear progression from monkey to man may give the wrong impression. The evolution of humans could not be reduced to a linear sequence.
Authors Note: The post has been updated for accuracy on July 23, 2020.