The Ethical Considerations of Pantropy in the Colonization of Mars, by Karim Jebari

Chapter in Garasic, M. D. & Di Paola, M. (ed.) (2024). The Philosophy of Outer Space: Explorations, Controversies, Speculations. Routledge.

Executive summary

In recent public and academic debate, the prospect of colonizing Mars has received renewed attention. According to some proponents, a permanent Martian settlement could reduce the risk of human extinction by functioning as an “Ark”, preserving human life if Earth were to become uninhabitable. However, human beings are not biologically adapted to a life on Mars, even with major environmental support systems. This chapter explores the concept of pantropy – artificially modifying humans to be able to survive in alien environments – and argues that it should be considered in a potential strategy to colonize Mars.

There are numerous reasons why Mars is inhospitable to humans. For example, humans living on Mars without protection would be severely harmed by charged cosmic rays and ultraviolet radiation. Another problem is the planet’s low atmospheric pressure, which would cause tissue damage. Furthermore, it would be difficult to meet the energy needs of settlements on Mars, as it is a relatively energy-poor environment. While technological solutions could, to some extent, address some of these issues, pantropy could be a way to make settlers less reliant on technological support systems and reduce the risks of living on Mars.

Some existing genetic traits may offer insight into how pantropy could be used to make human survival on Mars possible. For instance, certain birds living close to the Chornobyl reactor seem to have developed genetic traits that mitigate some of the harm caused by radiation. Other examples include instances where people who have lived in high-altitude environments for generations demonstrate adaptations to living in low-oxygen and low-air-pressure habitats. There are also examples of people developing adaptations to increased tolerance to high CO2 concentrations in the blood, and various genetic variations facilitating living in cold environments. These are examples of traits that might be combined with pantropy to facilitate survival on Mars.

However, beyond being a matter of technical possibility, the use of pantropy is a question of ethics. For instance, the medical procedure would entail risks that demand ethical consideration. On the other hand, it is important not to exaggerate the risks of new technologies. The risks should also be considered in light of the procedure’s benefits, which could be significant for the Martian settlers.

Some pantropy interventions may require modifying embryos, which also gives rise to ethical complications. As these procedures would limit the embryos' future life choices and affect their autonomy, it would be unacceptable for states to “produce” Martian settlers using pantropy. However, there is wide-ranging acceptance of parents’ more extensive rights to influence their children’s lives and health. This could, the chapter argues, in some cases include using pantropy. Arguably, Martian parents might even be morally obligated to use pantropy on their prospective children if it would improve their prospects of surviving.

Another concern is that the use of pantropy could eventually result in the Martian settlers becoming “non-human”, which might undermine its purpose of preserving humanity. However, whether the modified Martian settlers would be human depends on how the human species is defined. According to a common view, which claims that individuals belong to a species because of common origin and not because of similarities, the modified settlers would be as human as people surviving on Earth. Moreover, if pantropy makes life on Mars possible, it could preserve human culture and intelligent life. This would be valuable even if the Martian settlers were non-human.

In summary, the chapter argues that pantropy is something that should be considered if we are serious about creating an “Ark” by colonizing Mars. It outlines some of the reasons why Mars is inhospitable for humans and certain genetic traits that could be utilized in pantropy, as well as some ethical considerations related to the subject.

Read the whole chapter here.