Bioforming

Bioforming is a concept related to terraforming. Bioforming aims to transform life to improve its capability to survive, including on another celestial body (planet or moon), or other places. Life has evolved to be very well adapted. With genetic engineering and synthetic biology technologies continuing to push the boundaries of what is possible, bioforming also stems from the idea that it is likely to be easier to change life with such technologies. The intermediary concept between terraforming and bioforming is terrabioforming.

Microbial Life

Other planets and moons in our solar system are very different to Earth. Animals and plants, including humans, could never naturally adapt to occupy these environments as they would not be able to survive there in the first place. Microbial life, which is already surviving in extreme conditions all over the World will be much more capable of surviving on other planets and is much easier to genetically engineer.

Extremophiles

Microbial life can survive in many extreme environments, such as extremes of temperature, pressure, pH, and water availability. The field of astrobiology aims to define the limits of life in different environments in order to aid the search for life elsewhere in the universe.[1] So we have a good understanding of some of the capabilities of extremophilic microbes:

• Thermophiles can survive extremes of temperature up to 121 °C.
• Psychrophiles survive at temperatures below 15 °C (down to -20 °C [2]).
• Acidophiles are organisms with optimal growth at pH levels of 3.0 or below [3].
• Alkaliphiles are organisms with optimal growth at pH levels of 9.0 or above [4].
• Barophiles can survive extreme pressures, they are usually found at the seafloor.
• Anaerobes can survive in the absence of oxygen.
• Oligotrophs survive in environments with very limited energy sources.
• Radioresistant microbes can survive environments with very high UV radiation.

Microbes in Space

Although microbes have not reached other planets yet (or at least not been studied on other planets) due to comprehensive decontamination procedures, they have been used in many experiments at the international space station (ISS). For example, microbes have even been used to extract rare earth elements by biomining of asteroid material, showing that they are able to perform useful functions in the microgravity of space [5]. They have even shown an ability to adapt to the space environment by mutating rapidly [6], shining hope on life's potential to spread throughout the cosmos. Microbes can already survive in the void of space, albeit without reproducing, and extremophiles can probably already survive in certain habitats in the subsurface of Mars or in the oceans of Enceladus and Europa. But for microbes to survive on the surface of other planets, then modifications are probably required.

Synthetic Biology and Genetic Engineering

Synthetic biology has already been successful in improving the capabilities of microbial life in manufacturing, pharmaceuticals, and farming. For example, using metabolic engineering, microbes can produce biofuels or remove harmful mine wastes. By inserting the DNA of one extremophile into another, genetic engineering can combine the capabilities of different extremophiles so that multiple adaptations can be present in one organism. Then this organism can be optimised for survival in a certain environment by overexpressing the genes that code for proteins that are useful for the organism's survival.

Future Capabilities

As a case study, what capabilities could we give a microbe that would allow it to survive on Mars? (this is absurdly simplified (obviously))

1. First we need a good base species to add adaptations to. A species from the genus Pseudomonas spp. would be a good base as many are extremophilic and can survive in extreme cold, and some are capable of removing toxic perchlorate salts (the kind that are found in the soil of Mars)
2. Making sure that the microbe is not immediately killed is an important first step. If you're on this website, then you probably already know that Mars is very cold and a lot of radiation reaches the surface. So our microbe might need to borrow a few genes from a radioresistant microbe and a psychrophile for a bit of resistance to these extreme conditions. However, it might be a good idea to hide at least a few metres below the surface in the soil anyway.
3. Perchlorate salts (ClO₄^-) and hydrogen peroxide (H₂O₂) are two of the most common toxic chemicals in the Martian soil. We can choose a microbe that can already remove perchlorate salts using an enzyme called chlorate reductase [7], it might be a good idea to make it produce more of that enzyme (perhaps by coding for more promoters that cause more of the enzyme to be constructed). Removal of hydrogen peroxide can also be achieved by inserting a gene for a peroxidase enzyme, the enzyme catalase is probably a good choice as it turns hydrogen peroxide into oxygen that can be used by the microbe for growth.
4. But our Martian won't survive on just a bit of oxygen (and we should ideally choose an anaerobe as our base anyway). Carbon dioxide is extremely common in the atmosphere of Mars. So we might want to give it the ability to eat some of the carbon dioxide that dissolves into the soil from the atmosphere. Luckily, this has already been done with E. coli by inserting a pair of genes encoding proteins that are used by photosynthetic microbes to absorb carbon dioxide.

This sounds like a good start, microbes adapted to many different planets and moons can be imagined and bioforming microbes to survive on other celestial bodies is a crucial first step for bioforming any other species.

Humans

An illustration of the different men described in Olaf Stapledon's book 'Last and First Men'. Illustration by Vanga-Vangog on Deviant Art.

Humans are usually the first species that are thought of in the context of bioforming. Many science fiction novels have been written that describe the improved capabilities of a space-faring human race. For example, Olaf Stapledon's Last and First Men describes a range of different species of 'men' with different adaptations like antennae, wings, 6 fingers, and larger brains. The rate of development in the field of genetic engineering threatens a glimpse into this reality in the coming decades. But first, how have humans already adapted to environments on Earth?

Current

Humans have adapted to the various different conditions found on the Earth:

• People around the Arctic Circle are more adapted to cold and you can see them taking a swim or a sunbath on the beach when temperatures are just above 10 °C [8].
• Africans are more adapted to heat, but when temperature drops to 15 °C, you can see them wearing warm clothes [9].
• People around the Arctic Circle are used to eat meat and animal fat, but when they move to a large town, where their diet will consist mainly of vegetables, they get anemia [10].
• Europeans are most adapted for consuming milk, while Chinese people, where historically milk was not used for food, have a high percentage of lactose intolerance [11]. This is an adaptation made by the organisms of European people for their food regime.
• People that remained around the contemned zone in Chernobyl seem to have adapted to a certain level of radiation [12]
• People who live at the equator where there is more UV light have darker skin that protects them from absorbing too much UV [13]

Future

With current technology, it may be possible to adapt humans to live in some extreme conditions:

• Humans able to survive to extreme UV, X and cosmic radiation
• Humans able to hibernate for long interstellar journeys
• Symbiotic organisms, able to live with genetically engineered algae inside their body
• Amphibious race with gills and fins that can survive under water.
• Chemical resistant races (high concentrations of carbon dioxide or heavy metals)
• Races adapted to extreme cold. They would be hairier, larger (to aid in preventing heat loss), and might have thicker skin.
• Desert races that have adaptations for reduced water loss, heat resistance, and energy storage.
• Void races with protective impermeable skin, an ability to keep a minimal internal pressure, and a swallowed gel with oxygen in the lungs.
• Cyborg-set races (adapted to more easily accept digital implants).
• Humans that are able to produce their own food, such as by using sunlight or chemicals found in rocks and atmosphere.

Limits

Compared to other animals, humans evolve slowly. There are 3 important things that define how fast will a species adapt: the number of descendants per generation, the time between generations and the genetic pool. In case of humans, there are a small number of descendants per generation (even a few hundreds years ago, a family had an average of 6 children). Talking about the amount of time between generations, in case of humans, it usually is about 25 years. The genetic pool refers to how diverse is the DNA among the species. In case of humans, differences are not big, compared to animals. For example, humans have only 4 blood groups (and a few very rare ones), while animals have far more [14]. So, humans have a far smaller chance to naturally adapt to extreme environments and gain these new capabilities. Genetic manipulation is, therefore, required to circumvent this problem.

Survival is not the only requirement for humans as we have very complex emotional needs. To put it bluntly, there is no point in giving a human the capacity to survive on another planet if they have no will to live. So it is crucial that the environment around humans is managed to ensure that our complex needs are met. This may be in the form of the creation of a natural ecosystem prior to human colonisation.

Some environments like the heat of Venus or the lack of ground on Saturn might just be too extreme for bioforming alone to provide humans with the capabilities to survive.

The highly adapted races might not look like humans and will be too different from us to adapt back to Earth-like environment. So with a bioforming strategy, humans might always be stuck on the planet that they are born on, casting doubt on a Star Wars universe where people can travel to distant planets and moons.

Plants

Before humans step foot outside of an enclosed habitat into a planet without a space suit, plants should already exist as they are essential for our survival. They provide us with oxygen, food, medicines and they look after our mental wellbeing. Plants should be easier to transform than humans because they are simpler and don't have as many complex requirements.

Adaptations of current plants

Plants have a suite of complex adaptations that allow them to survive on almost every environment on Earth:

• In dry environments, plants produce a waxy coating around their leaves which prevents water from escaping.
• Plants have adapted poison to prevent herbivores from eating them.
• Some plants like lily pads have the ability to float on water so that they can get to sunlight easily in aqueous conditions.
• Cacti have large, fleshy stems that allow them to store water in desert environments
• Plants at the floor of rainforests have larger leaves since less sunlight reaches the rainforest floor
• Lichen has the ability to grow without soil

Future

An image of what plants might look like if they were adapted to another planet or moon.

There is a long history of genetically engineering plants to increase farming yields, food taste, and reduce farming costs. Applying some of this knowledge to space can go a long way:

• Adaptations to planets and moons with very low gravity that allow a plant to know which way is up (gravitaxis).
• Plants that have the ability to synthesise novel materials that are heat resistant (e.g. plants with metal or rock enthused stems)
• Timing adaptations that allow plants to synchronise with different seasons and day times on other planets and moons (phototaxis).
• More efficient photosynthesis on planets with lower levels of UV light (e.g. Mars) [15]
• Enhanced water and energy management to survive on planets with a limited water supply[16]

Limitations

Many planets are tidally locked, which means that one side of the planet is always facing the star whilst the other side is always in darkness. Needless to say, this presents a problem for plant life that aims to survive on the dark side of a planet. Luckily, Mercury is the only planet in our solar system that is tidally locked. Tidal locking most often occurs with moons, but tidal locking doesn't prevent light reaching both sides of moons.

Plants require symbiotic relationships with many other species of insects (for seed dispersal) and fungi (for nutrient acquisition) to survive. So engineering plant life to survive on other planets will require engineering of other life forms such as fungi, bacteria and maybe even insects. But realistically, seed dispersal drones are more likely to be prevalent on other planets than bugs.

Soil of other planets is unlikely to be suitable for plants. So a terrabioforming approach is most likely to be necessary to allow plants to colonise other planets.

Conclusion

Bioforming is possible with microbial life, and soon it might be possible to do the same with plant life. This presents a faster method to colonise other planets with life, and provide the foundations for an ecosystem that humans could colonise. Human bioforming is still very much a dream of science fiction, but in the future bioforming might be a much faster, and less costly method to colonise new planets. There are, however, many limitations to bioforming, which terraforming can help to ameloriate, thus terrabioforming is likely to be the best course of action.