By professor Jacob Palme, First version 29-May-2006, last revision 23-Mar-2012
Will the human species, Homo Sapiens, continue to evolve in the next millions of years? If so, how? What can we learn from what we know about Homo Sapiens development until now?
The Creation of Homo Sapiens
The human species (Homo Sapiens sapiens) started its existence between 110 000 and 50 000 years ago. Its development diverged from the apes about 5 million years ago.
The earth has been capable of supporting life for about 3 billion years, and is expected to continue being able to support life for between 200 million and 5 billion years in the future.
Using the higher estimate, if we view the period of being able to support life as 24 hours, then we are now about 9 o’clock in the morning, humans diverged from the apes about a minute ago and the human species started to exist 1-2 seconds ago.
Using the lower estimate, if we view the period of being able to support life as 24 hours, then we are now about one hour before midnight, humans diverged from the apes about 2 minutes ago and the human species started to exist about 5 seconds ago.
The average life span of a species on earth is a few million years. Every year, thousands of species cease to exist and thousands of new species are created. Will thus the human species cease to exist in a few million years, like most other animals? If so, why, and what will replace it? Or are humans so unique and different from other species, that experience from other species cannot be applied, and humans may continue to exist for a much longer time?
Note: This paper discusses many ethically and politically sensitive issues, and some readers will probably be offended by this. But the goal is not to give any views on what is right and wrong, what should be permitted or forbidden. The goal is only to discuss what will probably happen in the future of human evolution.
Differences between Humans and other Species
Humans differ so much from other species, that human future development may not be governed by the same principles as other animals. [Miller 2004] says that humans and human society should be seen as a fourth system of structured energy, Tetrology, different from the previous atomic, chemical and biological systems.
Miller says that humans differ in the use of advanced technology, use of controlled energy, use of clothes, use of sense-enhancements like glasses, telescopes or microscopes, advanced social organization, advanced language.
Also many religious organizations and other belief systems regard humans, or sometimes a subset of humans, as the chosen people, made by God to mimic himself.
On the other hand, it is apparent that many typical animal behaviors also occur in humans, as has been pointed out by [Morris 1967-1997] and [Diamond 1993]. Humans have a mating behavior and an aggressive behavior which is obviously inherited from our animal ancestors.
This is important when discussing the future of the human species, because humans may be so different that experience from animals cannot tell us anything about the future of Homo Sapiens.
How a Species Ceases to Exist
To discuss this issue, one must first discuss which processes causes a species to cease to exist. Some such processes are:
- The species is specialized to a natural habitat, which ceases to exist. The risk for this is rather low for the human species, because of its high adaptability to changing environments. A cosmic catastrophe like a giant meteorite will certainly kill most people on earth, but some will probably survive, and will rapidly proliferate again.
- In the case of humans, because humans have so thoroughly modified their environment (cutting down forests, carbon dioxide pollution, etc.) there is a risk that humans will themselves modify their environment in such a way that they cannot survive in it any more.
- The species is out-competed by another species, like the Neanderthals were out-competed by Homo Sapiens. There is today no existing species which might threaten the human species. There is a possibility that a new species, based on humans, may replace the human species, but then humans do not stop to exist, just continue in another form.
- The species gradually evolves, through natural selection, into a new species. Such evolution is however slow for such a large and wide-spread species as the human. It usually occurs in small, geographically isolated environments.
- The species is exterminated by a ruthless predator. This is the way the ruthless predator Homo Sapiens has exterminated almost all big animals on the earth. Also within the human species, races have been exterminated or nearly exterminated by other races, for example the Australian aborigines. Such extermination is nowadays labelled “genocide” and is very much disapproved of. No non-human predator threatening humans is likely to evolve, expect possibly a new species based on the human species.
- The human species might also be threatened by a new virus or bacteria, but experience indicates that it is unlikely that such a threat will appear, such that we will not be able to combat it or that the whole species will be exterminated by such a threat.
- When bacteria grow in a mold, they reach a stage where there are too many bacteria, and they all die because of overpopulation.
How a New Species Can Replace Homo Sapiens
A new species, to replace Homo Sapiens, might be created in different ways:
- By natural selection in a limited population (New species occur mostly in limited populations, [Mayr 2001 p. 136]. Widespread species undergo little evoutionary change [Mayr 2001 p 254].) This is not very probable, since the tendency to intermingle among all humans is very large. Much more probable is that the human species itself evolves without splitting into a new species [Mayr 2001 p. 191], but also such evolution is not very probable, at least in a short time range [Mayr 2001, p. 261].
- By explicit creation through breeding or genetic manipulation of Homo Sapiens. This is the most likely alternative. When parents are given the option of creating better-than-average children, it can be expected that many parents will choose this option. Even if politicians talk a lot about the ethics of genetic manipulation, they will in practice probably not be able to stop some people using this option.
- By explicit creation through breeding or genetic manipulation of another species. But no such species very suitable for replacing humans exist.
- By an artificially created species. This might even be based on computers and not on biology. However, we are very far from this option today [Pearson 2004]. “Artificial intelligence” is a branch of computer science, but its results until now are very far from creating a species which can outcompete humans. No computer has the general adaptable intelligence of humans, nor can they even reproduce themselves.
Has Homo Sapiens Evolved Before?
Modern Homo Sapiens originated between 110 000 and 50 000 years ago. But until 50 000 years ago, it existed only in Africa. Then, in just a few thousand years, the art suddenly expanded into the whole of Europe and Asia, and eradicated all the rests of previous humanoids like Homo Neanderthalus and Homo Erectus [Klein 2004]. Many anthropologist believe that this must have been caused by a genetic mutation, for example a mutation which increased the language capabilities. Other’s claim that the human brain has not changed for 150 000 years [Mayr 2001, p. 252]. But they base this claim on fossils, and fossils may not show changes in the organisation within the brain.
After that, Homo Sapiens continued to live as a hunter-gatherer until about 10 000 years ago, when agriculture suddenly began and rapidly changed the prosperity of Homo Sapiens. Why did this suddenly happen 10 000 years ago? Many anthropologists believe that again, the cause was a mutation, probably in the area of linguistic skills.
Genetic research shows that certain genes related to the brain size did change between 5 800 and 37 000. Exactly this gene cannot explain changes in humans, since not all intelligent humans have this particular gene. But the fact that genes related to brain size have changed in this time span indicates that humans are still evolving [Warner 2005].
One of the researchers behild this result is qouted as saying “Our studies indicate that the trend that is the defining characteristic of human evolution — the growth of brain size and complexity — is likely still going on If our species survives for another million years or so, I would imagine that the brain by then would show significant structural differences from the human brain of today.”
Thus, it seems as if Homo Sapiens has evolved, and as if the major evolutionary events occurred quite suddenly. If this continues, we can expect that a sudden good mutation perhaps 10 000 years into the future can again change Homo Sapiens by natural selection. Of course we do not know exactly when this mutation will evolve.
How Homo Sapiens can Evolve
Homo Sapiens can evolve through natural selection or through breeding or genetic manipulation. Breeding and genetic manipulation is most probable for a few people in technically evolved countries.
Natural selection is most effective when many animals die before reproduction. Thus, natural selection is more effective in developing countries. In industrial countries, medical development allows most of those who would die to live and reproduce.
The size of the brain of humanoids has increased three times in the last two million years [Hofman 2002]. This icnrease has meant more connections, less nerve cells. This means that with the current design, the brain cannot become more than three times larger than it is today. Other studies [Pearson 1997] indicate similar results.
Note that a species need not evolve. Some species remain identical for hundreds of thousands or millions of years [Meyr 2001, p. 193, 195]. And the evolution of humans has had long periods of little change, such as the Homo Erectus which did not change very much for 1.5 million years.
Will Homo Sapiens Deteriorate
Some people say that the lack of effective natural selection for humans in industrial countries will cause the human species to deteriorate, since natural selection is necessary to keep a species healthy. As a simple example, the existence of spectacles would cause more people to be born near sighted.
However, this is counteracted by immigration of people from less developed countries. This immigration is today so large, that it can probably counter the risk of deterioration of the species as a whole.
Also, future use of genetic manipulation and intentional breeding can be expected to counteract degradation.
Genetic Manipulation and Artificial Breeding
Genetic manipulation and artificial breeding is today disliked, because it was used in earlier years by governments in questionable ways. Most known is the Nazi ideas of killing or sterilizing “inferior people” like Jews and people with mental illnesses. Also in non-Nazi countries, enforced sterilization was common earlier, but is not done so much today.
The reason for this is that such government control is today not regarded as ethical, and also that the efficiency of such schemes is debatable. All schemes which reduce the genetic variation within the human species can cause more harm than value.
In spite of this, it is my belief that genetic manipulation and artificial breeding will be important in the future, but not done by the governments but by parents. Already, today, more and more pregnant women voluntarily screen for disabilities and genetic diseases of the faetus and choose abortion rather than giving birth to a child with a genetic illness [Tännsjö 1999].
This will probably become much more common in the future, with better medical and technical options of influencing the genes of future children [Pearson 1997]. There will certainly be a lot of discussions about the ethics of this, but my belief is that positive genetic manipulations will eventually become accepted ethically. And this might create a race of superhumans, which might even become a new species threatening its creator.
Evolution of Human Cultures
One can note that a Darwinian type of evolution today does not exist only for Homo Sapiens itself, but for various cultural organisations of humans. In particular, the economic competition on the world market has many Darwinian features, with survival of the fittest as one central function.
Do You Agree?
If you do not agree, or have more ideas on the future of Homo Sapiens, you are welcome to comment on this paper. Your comments may influence future versions of it. A forum for discussion is available.
The original of this paper can be found at http://web4health.info/en/aux/homo-sapiens-future.html.
There is not very much written about the future of Homo Sapiens. There are a large number of books about evolution and human evolution and about how humans were formed by evolution, and this is important for understanding what will happen in the future. Here are presentations of some such books:
- [Diamond 1993]
- The Third Chimpanzee: The Evolution and Future of the Human Animal
- By Jared Diamond.
- ISBN 0-06-018307-1.
- HarperCollins publishers 1992.
- A collection of essays, many of them give essential insight into how and why humans are as they are.
- [Hofman 2002]
- Limits to Human Brain Evolution
- By Michael A. Hofman
- Discusses the growth of the humanoid brain size and its limitations.
- [Klein 2004]
- Vetenskapsradion historia, Sveriges Radio, 2004-01.
- By Tobias Svanelid and Richard Klein
- An interview with Richard Klein, professor of anthropology.
- 11:16 minutes, mostly in Swedish, MP3 format
- [Leakey and Lewin 1977]
- Origins: The Emergence and Evolution of Our Species and Its Possible Future
- By Richard E. Leakey and Roger Lewin.
- ISBN 0-525-48013-7.
- E. P. Dutton publishers 1977.
- A detailed and interesting overview of all the stages of evolution of Homo Sapiens since the separation from the monkeys 5-7 million years ago.
- [Mayr 2001]
- What Evolution Is
- By Ernst Mayr, Basic Books, 2001.
- Lots of information about how Darwinian evolution works.
- [Miller 2003]
- From DNA to ABC
- By Joel Miller.
- ISBN 91-972454-3-7.
- BenTarZ Productions, 2003.
- A collection of essays, many of them give interesting ideas on human development and human languages development. Are humans distinguished from the monkeys by the use of tools? But monkeys also sometimes use tools. Are human distinguished by building houses? But beavers and birds also build nests.
- Miller claims that modern human society is a distinct new stage which he calls “civil society”. I wonder if historians five hundred years from now will agree with this?
- On the future, the author says that implanting of electronics inside the human body will be an important feature of how people live in the future. I agree with him, this is quite probable an area where major changes in our lifestyle will come in the future.
- [Bryant 1999]
- Evolution of animals and the age of reptiles
- by Peter J. Bryant
- An overview of how life started and developed on earth. Life started 3 billion years ago, multi-cellular organisms 2 billion years ago, complex organisms 600 million years ago, mammals outcompeted the dinosaurs 65 million years ago.
- [Miller 2004]
- Tetrology and the Tetrastic System
- By Joel Miller
- A presentation of the view that the human system of organizing knowledge is so different from the previous atomic, chemical and biological systems, that is should be seen as a forth, Tetrastic system.
- [Pearson 1997]
- The Future of Human Evolution
- By Ian Pearson
- Darwinian Evolution will have limited impact on the future of Homo Sapiens, since other kinds of evolution, such as breeding, genetic engineering and electronics will take over as dominant factors.
- [Pearson 2004]
- The Agile Investment Bank
- By Ian Pearson
- Darwinian Evolution in competition between companies.
- [Tännsjö 1999]
- Coercive Care: The Ethics of Choice in Health and Medicine
- By Torjbörn Tännsjö (London and New York: Routledge, 1999)
- [Warner 2005]
- Human Brain Still a Work in Progress
- By Jennifer Warner, The Human Genome Project, citing: Evans, P. Mekel-Bobrov, N. Science, Sept. 9, 2005; vol 309: pp 1717-1720; 1720-1722. News release, Howard Hughes Medical Institute. News release, University of Chicago Medical Center, Science Daily.
- [Morris 1967-1997]
- The Naked Ape, The Human Zoo and Intimate behavior, The Human Sexes, The Naked Eye
- By Desmond Morris
- ISBN: 0-385-33430-3, 1-56836-163-7, 0-09-1878675, 0-563-38358-5.
- These three books which give many interesting insights into how human behavior is governed by our animal past.
- [Klein 2004]
- Vetenskapsradion historia, Sveriges Radio, 2004-01.
- By Tobias Svanelid and Richard Klein
- An interview with Richard Klein, professor of anthropology (in Swedish, MP3 format).
- Human evolution has developed cognitive modules of thinking
- Human evolution has developed jealousy
- Human evolution has developed anger, aggression, violence
- Cognitive errors in human thinking
Original Article reprinted with permission from here.