Space - the spaceship "Humanity" / Cameron M. Smith

How will future generations make the journey from our home on Earth to the other planets and beyond - and what will be the consequences for the human race

When the space shuttle Atlantis skidded into orbit, slowed and stopped in 2011, it was not the end of human space travel, as some feared. Basically, just as the extinction of the dinosaurs allowed the first mammals to thrive, so the end of the shuttle age marked the opening of a much larger window of opportunity for space exploration. Following some pioneering and ambitious private companies, we are currently in the first stages of man's migration from Earth and his adaptation to life in other worlds. Mars is the declared goal of Elon Musk, one of the founders of PayPal; of polar explorers Tom and Tina Seargan, who are planning a private expedition to Mars; and of the European MarsOne project, which is financed with private funds and aims to establish a colony on Mars by 2023. The settlement of space begins now.

 

But it is not just a question of technology. The success of the space settlement, in the long term, depends on careful handling not only of engineering factors, but also of biological and cultural factors. The settlement of space is not only a matter of robots and missiles, it must also take into account humans and their bodies and their families, communities and cultures. We must begin to build an anthropology of space settlement so that we can deal with the ambiguous, dynamic, unordered, and sometimes boiling world of human biocultural adaptation. And in the planning of this new plant we must not forget the most obvious fact, an attack on all life: life is constantly changing in the process of evolution.

 

The way we think about the settlement of space today is based on three main ideas. First, colonization of Mars. The plan, which was widely publicized thanks to the work of the sharp space engineer and president of the "Mars Association", Robert Zorbin, includes colonies that will provide for their own needs. They will produce water, oxygen and building materials from the local resources. The second idea is the concept of the floating colony: huge living facilities that will be built from metals that will be known on the moon or asteroids. Thousands of people will live in these colonies, described by physicist Gerard K. O'Neill in the 70s. They will be able to rotate on their axis to create a sense of gravity (as beautifully illustrated in the movie "2001: A Space Odyssey" from 1968), and circle the Earth in an orbit or stand in place at "La Grange points" - areas in space where the orbital circuit of an object Offsetting with the gravity of the earth, the moon and the sun. And thirdly, we must also think of a kind of spaceship Noah's Ark: a huge space vehicle that will carry thousands of settlers away from Earth in a multi-generational one-way journey. I worked with the non-profit organization, Icarus Interstellar, to design just such a plant.

 

Each of these approaches has its own advantages, and in my opinion, the three approaches are the reality commitment from a technological point of view if humanity goes into space en masse. But the settlement of space must not be confused with the occupation of space. The world beyond Earth is vast beyond imagination, and it will remain so. When humanity starts building homes for itself in space, it will undergo a change.

The pioneers

Who will be the first to settle in space? Here we have to get rid of the old concept of an elite team and of ridiculously wicked tests passed by space heroes with good looks like in the movie "The Elite Team". The inhabitants of the space will be ordinary families and communities, who did not go out as an expedition but with the intention of living their lives in space. We will certainly need a few captains like Captain Picard, but most of the first settlers will surely be farmers and builders.

 

Still, the former should have healthy genetics. In small populations, carriers of genetic diseases can endanger future generations much more than they endanger them in populations of billions, where the danger is zero in sixty. In a "space box", the biological fate of the colony depends greatly on the genetic composition of the founding group. Even with only a few of those who set out on the journey at the beginning carrying genes for a hereditary disease, it is possible that the disease will become widespread in the population of the colony for generations.

 

Today we have detailed information on hundreds of genes that cause syndromes and diseases, from cancer to deafness. (Researchers recently announced that by examining embryos it is possible to discover more than 3,500 such traits today). [See: "Determining the gene sequence of embryos", this issue, page XX.] The genetic screening program should therefore be simple: carriers of certain genes will remain on Earth. But it's not that simple. Many of the diseases are polygenic, meaning they are the result of complex interrelationships between many genes. And even if a person carries a gene, or several genes, for a certain disease, the environmental factors to which he is exposed during his life can determine whether these genes will be activated in a healthy way or will trigger the disease.

 

For example: the human gene ATRX Helps in controlling processes related to the transport of oxygen in the body. But diverse environmental factors, from diet to mood, affect its operation. When the garden operation ATRX Goes awry to a considerable extent, oxygen transport is impaired in a way that may cause convulsions, mental disability and stunted growth. Therefore, you cannot simply dismiss a carrier ATRX Because we are all carriers. But there are people who the mechanism ofATRX Theirs is out of control under environmental conditions that are not well understood. Can we exclude a person from the space settlement based on whatmight To happen?

And what complicates things even more is that we must also ensure diversity in the genetic pool of the settlers. If all individuals in a population are genetically too similar, one outbreak of some disease could kill them all. (This argument demolishes the idea of ​​genetically engineering a superrace of space travelers, as presented in the 1997 film "What Happened in Gataka?").

After sorting, what should be the number of people in a space colony? In a colony on Mars, the population will be able to grow and spread to new territories. But in a "space box", the population will be relatively small, and there will be the fear of pairings of relatives. For example, in a study done in the populations of the Amish sect in the USA and other small populations in India, Sweden and the state of Utah, it was found that infant mortality is approximately twice as high when the parents are cousins ​​compared to parents who are not relatives.

To avoid this problem, it is necessary to find out what is the minimum size at which a population can maintain a healthy genetic pool. This question has been discussed a lot, but there are anthropologists who believe that this number stands at 500 souls. Since small populations are always more in danger of collapsing, I would suggest starting with a population at least four times larger than that, meaning a group of about 2,000 people, something like half the number of personnel in a well-manned aircraft subject. The journey in space must be in a spacecraft spacious enough to allow this population to grow. For a human population sailing away from Earth, size is definitely an advantage. (Even on interstellar journeys, the travelers will try to find another solar system and settle planets there, so that the population can regenerate and grow.)

One should also pay attention to the demographic composition of the settlers: their age and gender. Computer simulations built by my colleague William Gardner-O'Kearney show that populations with a certain ratio between young and old and between women and men are better preserved several hundred years later, compared to populations whose starting ratios were different.

If so, the first groups of settlers should be diverse and the individuals in them should be healthy to optimize the offspring's chances of having genes that enable adaptation to new environments. But there are things beyond our control. There will be a moment when we will have to roll the genetic dice, which we do anyway every time we bring a child into the world here on earth, and get out of our addiction on earth.

Natural selection in space

The preparation of the settler population will be as meticulous as it may be, life outside Earth, at least initially, will be more dangerous and perhaps even shorter than life here. Far away, people will be subject to forces of natural selection that no longer affect us in the modern world. The effects of this choice will not be as dramatic as in science fiction films, which deal mainly with adults. Most of them will manifest themselves precisely during the crucial period of tissue development in fetuses and babies, a period when life is most vulnerable.

What will this natural selection manifest itself in? Give your opinion, for example, that in the last few million years the human body developed near sea level at a pressure of one atmosphere and got used to breathing an air mixture of about 80% nitrogen and 20% oxygen. But the journeys in space require a stay in an environment of artificial pressure, the installation of which is expensive and requires a lot of work the greater the required pressure. To ease the engineering constraints, the atmospheric pressure in any extraterrestrial structure will be lower than the pressure on Earth.

Although the astronauts in the "Apollo" missions held up well even at a pressure of one third of an atmosphere, but when you lower the pressure, you have to increase the concentration of oxygen in the air you breathe. (These astronauts breathed pure oxygen on their trips to the moon.)

Unfortunately, both low pressure and high oxygen concentration interfere with embryo development in vertebrates. The rate of abortions and infant mortality will be high, at least initially. Naturally, natural selection will preserve the genes that are suitable for the conditions outside the earth and get rid of the genes that are less suitable for them.

Infectious diseases, which particularly affect small and dense populations such as those in space, will pose a serious problem and will also dictate natural selection. No matter how careful we are about vaccinations and quarantines, eventually plagues will attack the colonies and only those more resistant to the disease will be condemned to life.

Besides this, let's not forget that we will also bring with us thousands of domesticated animals and cultivated plants that will provide food and raw materials, and the pressures of natural selection will act on them as well. They will also act on the millions of species of bacteria that travel with us inside our bodies as invisible genetic hitchhikers essential to our health [see "The Perfect Social Network", by Jennifer Ackerman, Scientific American Israel, October-November 2012].

Based on some calculations, I believe that within five generations of 30 years, that is, within about 150 years, these changes will give physical signals to the humans in the extraterrestrial colonies.

The question of exactly which biological adaptations will develop is highly dependent on the atmospheric and chemical environment of the constructed habitats. We can control these conditions to a great extent. But it is difficult to control two other important factors that will shape the human race in space: gravity and radiation.

The gravity on Mars is one third of that on Earth. Natural selection under these conditions will probably favor a lighter and more flexible body structure, which moves more easily than the heavier and more muscular bodies that we use to fight against the Earth's gravity. In a spacebox and other free-cruising scenarios, gravity may remain as on Earth, so the Earth-like body structure may be preserved.

Radiation in space causes mutations, and it is likely that most space colonies will not be protected from it as effectively as Earth is protected by its magnetic field and atmosphere. Will the increased rate of mutations cause the proliferation of physical defects such as the recurrence of organs, for example an extra finger, or deformities such as a cleft palate? Absolutely, but we cannot know what defects will be discovered. The only thing we can predict with some degree of certainty is that natural selection will favor immunity to radiation damage. There are people whose DNA repair mechanisms are relatively good and active, and they will have better chances of passing on their genetic load to future generations.

Could it be that the efficient DNA repair mechanisms have an affinity for some external feature, such as hair color? Here too, we do not know. But beneficial genes can spread through a population even if they are not associated with a trait that can be seen with the eye. Among the Hutterites in South Dakota, who breed within a relatively small group of small communities, anthropologists have discovered evidence that body odor strongly influences mate selection - and the better a person's immune system, the more pleasant their smell, surprisingly.

So, over an average time span of five generations, the human body will change slightly depending on the environment. We can see adaptations of the type we see in the inhabitants of the high areas of the Andes and Tibet, who have developed a more efficient physiology for transporting oxygen in the body such as a wider and deeper chest. But any change is a compromise, and these populations suffer a higher rate of infant mortality due to being born at high altitude. One of the cultural adaptations to this biological change is that women in labor descend to lower places, where there is more oxygen in the air, to give birth. Similar biocultural changes are therefore to be expected outside of Earth, and we should prepare for the most likely changes. For example, on Mars, mothers may travel to a space station orbiting the planet, where their child will be delivered in a rotating facility that will provide Earth-like gravity and atmosphere. But I would guess that eventually this habit will be abandoned and distinct human-reddish characteristics will develop.

space culture

Cultural changes will be more visible than biological changes in the first 150 years. Studies conducted on immigrants show that although they usually preserve part of their tradition to maintain their identity, they also invent new customs and traditions in accordance with their new environment. For example, the first Scandinavian settlers in Iceland in the ninth century AD and later, added to worship the Norse idols and speak the language of the Vikings, but also developed very quickly, while discovering this unknown land, a variety of unique foods, rich in meat (compared to rye and oats grown in Scandinavia) and preserved food , which are necessary to survive the harsh winters.

On Mars, this cultural acclimation will manifest itself in many ways. There will be an atmosphere rich in oxygen at a lower pressure than the pressure on Earth. The residents will live in buildings with special structures and materials. It is therefore possible that the sound waves will progress differently in the air, even if only slightly, and this will affect the pronunciation of the words and perhaps also the rate of speech, and it is possible that new idioms and accents will develop. The weaker gravitational force in Mars may affect body language, which is an important element in communication between people, and is expected to affect the performing arts of all kinds. And this is exactly what results in the development of a new culture: the accumulation of many small differences.

Deeper cultural changes can occur in the space arks, where life will gradually become disconnected from life on earth as the ark sails on. In this case, concepts of space and time can change quite quickly. Until when, for example, will the inhabitants of the space boxes continue to measure time according to the standard of the earth? Without Earth's days, nights and years, such a culture might develop a decimal time estimate. And perhaps they will decide to count the time backwards, until a future moment when they will reach some distant solar system, and not forward, in relation to some event that happened in the past (such as the day they left, never again, the Earth.)

Long-term genetic changes

Major genetic changes happen when new genes spread through the population. One of the prehistoric examples is the spread of genes that allowed adults to digest lactose (sugar found in milk). The genes appeared separately, both in Africa and in Europe, shortly after humans began to domesticate cattle. This genetic "tool" allowed humans to extract more energy from cattle, and soon this change became universal or "permanent".

While we cannot predict which mutations will spread, the science of population genetics allows us to estimate how long it will take for mutations to become established in the space pioneers' genomes. Calculations I made according to several models of a Mars population of 2,000 people in different compositions of sex and age indicate that such a fixation may occur within only a few generations, and certainly within 300 years. That is, one can expect prominent and distinct physical features to develop in the various space populations during this period of time. These are differences like those we find between distant populations on Earth: a range of heights, skin colors, hair types and other characteristics.

On Mars, there may be further differentiation, within the Martian population itself, if there are groups that prefer to spend most of their days protected underground, while others prefer to live in facilities on the surface of the ground, which are more exposed to radiation but provide greater mobility. In the "space box" scenario, where the population is limited and confined to one place, fixation of genes can happen much faster, and it is possible that it will lead to greater genetic uniformity than on Mars.

Any biological changes are therefore expected, but the long-term cultural changes will be more profound. Consider that in 300 years, from the beginning of the 17th century to the beginning of the 20th century, the English language has changed so much that it takes special training to understand an English text written back then. After 300 years of travel, the language spoken in the space box could be very different from the one spoken when the box set out.

It is likely that even broader cultural changes will apply. What exactly is the line that separates one culture from another is a subject of great controversy among anthropologists, but in my opinion the anthropologist Roy Rapaport made it very clear: cultures differ from each other in their "fundamental sacred assumptions", certain and indisputable core ideas, which are embedded in traditions and rituals and shape the The basic philosophical and moral code of the population. In Christian culture, for example, one of these sacred assumptions is the verse: "In the beginning God created the heavens and the earth". It is impossible to know how long it will take for such basic beliefs to change at distances from Earth and how they will change, but there is no doubt that a few centuries are enough for new cultures to appear.

The Rise of the Outer Man

When we'll see Biological changes deepen even more, to the point of the formation of a new human species? Small populations can change quickly, as demonstrated by the giant mice roaming the Faroe Islands today, 1,200 years after Viking ships brought common house mice there. But apparently, from an anatomical point of view, more than 100,000 years of migration from Africa to all kinds of new environments, from deserts to the expanses of the oceans, have passed for modern man without a new species being formed. (The hominin species closest to us, such as the cold-resistant Neanderthals and the "Hobbits", the dwarf humans whose remains were discovered on Flores Island in Indonesia, split from our lineage much earlier.) This is mainly because we use culture and technology to adapt, and not just biology alone. Heavy selection pressure would therefore be required to alter the extraterrestrial humans so much that they would not be able to mate healthy offspring with Earth mates.

Unless, obviously, humans created the new species on purpose. It seems that sooner or later the extraterrestrials will harness the tremendous power of DNA to adapt their bodies to all kinds of environmental conditions. It is possible that the inhabitants of Mars will use genetic engineering to grow gills for themselves, with the help of which they will produce the oxygen bound to the carbon dioxide molecule in the atmosphere, or they will strengthen the skin tissues so that it can withstand the low pressure. It is possible that they will be made into a new species, the extraterrestrial man, Homo extrasterialis, by choice.

Where to start?

Human settlement in space will require many technical and engineering developments. We must also better understand how biology and human culture adapt to new conditions and use this knowledge to benefit the success of the space settlement enterprise. In my opinion, it is worthwhile to start today in three directions of action.

First, we need to abandon the technocratic human resistance to procreation in space and start doing it: giving birth and raising children outside the Earth, to understand the vital issues concerning human reproduction, the development of the species, and growth under different conditions of radiation, atmospheric pressure and gravity. The bureaucratic bureaucracy will probably shy away from exposing children to a greater risk than not wearing a bicycle helmet in the suburbs of the Western world, but the concern will be forgotten when access to space is privatized. Still, the adaptation to the space will be painful, and the birth is also painful.

Second, we must experiment with raising and maintaining the health of extraterrestrial domestic animals. We don't go anywhere without the bacteria in our bodies, plants and animals.

To further these two goals, a prize, like the X-Prize, should be given to the first functioning habitat that would allow life outside of Earth: not a sterile laboratory circling the Earth like a satellite (without detracting from the importance of such laboratories), but a home where people can grow plants and animals , and even children. Many will be disgusted by the thought of living in such a place, but on the other hand, there will be no shortage of volunteers either.

And third, we must return to the approach of proactive action thanks to which man has survived until now, and use this ability to shape our evolution outside our planet. We have to be much braver than the bureaucratic authorities, because if we don't, we will become extinct one day as has happened and will happen to all species on earth. And as H. G. Wells wrote about the future of humanity in 1936, it is a question of "the whole universe or nothing".

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About the author

Cameron M. Smith teaches human evolution at Portland State University. He has written about evolution in the journal Scientific American Mind and in his books "The Fact of Evolution" (Prometheus Publishing, 2011) and "Emigrating to Extraterrestrials" (Spinger Praxis Books, 2012).

in brief

A space expedition where people will be isolated from Earth for a very long time, such as a colony on Mars or a multi-generational journey to a nearby planet, will inevitably lead to the development of new physical and cultural traits.

Life in spaceships for long distances will pose unique environmental challenges such as strong radiation and low atmospheric pressure. Their effect will be greatest in the vulnerable stages of life: in the womb and immediately after birth.

The mission planners will have to carefully select the "team" of space travelers. The goal: a population that is genetically healthy, yet diverse enough to withstand the plagues that may hit it from time to time and thrive in environments different from the Earth, which is fundamentally different.

More on the subject

Leaving Earth: Space Stations, Rival Superpowers, and the Quest for Interplanetary Travel. Robert Zimmerman. Joseph Henry Press, 2003.

Shielding Space Travelers. Eugene N. Parker in Scientific American magazine, Vol. 294, no. 3, pages 40-47; March 2006.

How to Live on Mars: A Trusty Guidebook to Surviving and Thriving on the Red Planet. Robert Zubrin. Three Rivers Press, 2008.

Emigrating Beyond Earth: Human Adaptation and Space Colonization. Cameron M. Smith and Evan T. Davies. Springer Praxis Books, 2012.

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