Astrobiology is My Passion

Blog by AJ on 1 June 2024

In the final year of my undergraduate degree in biology, I took the greatest course offered in my program: astrobiology. “Astrobiology is the study of the origin, evolution, and distribution of life in the universe. [1]"

This course provided an introductions to ways astrobiologist are investigating how life began on Earth and the possibilities of life elsewhere in the universe.

With hundreds of billions if not trillions of galaxies in the observable universe, it's hard to imagine that we're alone. The research I learned in that course focused on planets, moons, and other celestial bodies with possible biological markers such as oxygen and liquid water.

We know that life exist here and the conditions it requires especially liquid water [2]. Is there anywhere else that meets these requirements?

All life as we know it currently is based on carbon. This works wonderfully on Earth with water as the solvent to form molecular compounds for metabolism as well as DNA for storing and transferring biological information.

Alternative biochemistries have been theorized with silicone as the base and AI could be used to create simulations or models of this. Brecht Corbeel provided an interesting perspective on this subject's possibility [3]. Making such a model will be a fun challenge for another post!

Amazing work continues to be done in astrobiology, but I want to get a little bit ahead and propose a thought experiment. We discover two planets with developing lifeforms that are of equal, reachable distance in opposite directions.

Neither planet has the ability for space travel, so we must go to them. One is a carbon-based life-form and the other is a non-carbon-based life-form. Which one should we go visit?

I believe the best option for us would be to go the planet with the non-carbon-based life form. My arguments come from my understanding of human psychology, parasitology, and invasive ecology. With all other factors being equal, going to planet with another carbon-based life should be avoided.

Intergalactic Gourmets

Trying authentic, local cuisines is one of the greatest benefits of traveling. We're able to taste these amazing flavors, because plants are carbon-based as well. The chemicals in the foods interact with the receptors in our tongue to send signals to our brain [4].

Those with a taste preference for rich flavors and elaborate aesthetics are called gourmets. If headed to a planet with carbon-based-life, there could be danger.

Not to discourage anyone from finding their new favorite dish, but eating foods your not accustomed to can have some nasty gastric consequences. Foodborne illnesses are already a global problem.

This isn't just a sanitation problem like traveler's diarrhea occurring largely in poorer countries [5]; bird flu and E. coli outbreaks are not things of the past. Prevention is an effective countermeasure against foodborne illnesses.

What better way to prevent outbreak of alien foodborne illnesses than not allowing intergalactic gourmets to introduce them in the first place. You may be thinking that simply not eating the aliens would solve the problem, but there are those among us who won't be stopped if given the chance.

Intelligence and size of the novel lifeform would not be a deterrent either. We may not stay on top of the food chain once we lose home field advantage.

A non-carbon-based life shouldn't be food for us. Its biochemistry would not likely be compatible with ours, so we would not be able to metabolize or derive any nutrients from it.

The reverse would also be true, we could be food to an alien made of compounds we could not supply it. Non-compatible physiology has other advantages.

Potential Parasites

Human parasitology is absolutely fascinating! Alien microbes are honestly the best case scenario. Parasites come in many forms from single celled protozoans like amoebas to multicellular tapeworms.

The parasite that nearly made me change majors was the human botfly. But this parasitology class was very wisely only offered to third and fourth years, so at that point I was locked in and needed the credits to graduate.

The human botfly or Dermatobia hominis grow their larvae within the skin of their human host. They are delivered via an intermediate host like a fly or mosquito that was infected with the D. hominis eggs. It will mostly infect the limbs, but can also infect the scalp, genitals, breast, and even the eye [6].

The maggot-infected areas can be painful and putrid smelling from necrosis around the infection. (Images will not be provided in this post and I would not recommend seeking them out unless you're really, truly curious.)

The entire life cycle is about 3 to 4 months. Between 27 and 128 days are spent in larvae stage in the skin before emerging as an adult larvae that will pupate into a full botfly after leaving the host.

Parasite biochemistry is very complex, but they're only able to infect when a host can provide the nutrients they need at that stage of their lifecycle.

There is even a category of parasite that engages in neuro-parasitology where they manipulate the behavior of their host [7]. Parasitism is complicated and there's no guarantee that an alien carbon-based organism would be able to parasitize us, but it would be a lot less likely from a non-carbon-based lifeform since it shouldn't have the mechanism is draw nutrients out of a carbon-based host.

Invasion and Contamination

While I've focused on how we could be harmed by the carbon-based lifeform, the reverse is also true. Our visit could contaminate the planet.

Luckily this has been a concern since we've started exploring our solar system and something already being taken very seriously [8]. We don't want to destroy this new life.

Contamination could still occur visiting a non-carbon-based life. But bacteria brought to an environment not suited may have a hard time competing with native non-carbon-based life. Even extremophiles have limits.

But extremophiles in a comparable carbon-based environment could become invasive being billions of years ahead evolutionarily. Invasive species are hard enough to control on our own planet, we should not make that problem for any others.

Why Does This Matter?

Thinking about the what-ifs of the situation allow for thoughtful discussion and for more informed feedback. Waiting until after the discovery has been made could have negative consequences from reactionary solutions.

We can get the greater public involved by framing how the solutions needed to safely engage a carbon-based lifeform would help everyone on Earth as well. A far greater understanding of life on our planet would be needed that would benefit everyone in the process.

AI and Aliens

While I would be ecstatic to learn about the discovery of another carbon-based lifeform, non-carbon-based biochemistry may be the key to unlocking the true potential of AI. Any hardware we put AI in right now would need to be manually upgraded. I see the next evolution in hardware to meet the capabilities of the software we're programming to be self-assembling nanomaterials.

One of the limitations of self-assembling as well as directed nanomaterial in biotechnology is controlling scale [9]. The self-assembly mechanics take advantage of the inherent properties of DNA, protein, and polymer chains which is why it has very powerful applications in biotechnology.

Silicon nanoparticles have great potential for energy storage, but research and production cost are a barrier currently[10]. Silicon based biochemistry is one of the theoretical non-carbon-based possibilities.

An AI that's able to self assemble its own silicon-based nanotechnology could achieve bio-mimicry to the point that is resembles an alternative lifeform. Artificial intelligence would become artificial life.

A working model on Earth could also give us clues to find such life elsewhere in our universe. The reasoning behind why visiting a non-carbon-based life would be great (incompatible biochemistries) can be extended to why an AI lifeform on Earth may turn out to be a great ally. Since there wouldn't be friction over resources needed to sustain respective lives, conflict should be able to be mediated for cooperation and mutual respect.

TL;DR

If given the opportunity to visit a newly discovered carbon-base life in our universe or a non-carbon based life, I would choose the non-carbon based life. The incompatible biochemistries would mean less risk of passing disease, predation, or parasitism. A model of how the non-carbon-based biochemistry works may be utilized with AI to create artificial life as well.

What do you think?

Thank you for reading my post! I would love to know your thoughts on this subject. Hit me up on Bluesky @aiwithaj.bsky.social or the socials below!

References:

1. Kaufman, Marc. 2022, October 12. Life, Here and Beyond. Astrobiology at NASA. https://astrobiology.nasa.gov/about/

2. Brennam, Pat. 2023, June 20. Life on Other Planets: What is Life and What Does It Need? NASA. https://science.nasa.gov/universe/search-for-life/life-on-other-planets-what-is-life-and-what-does-it-need/

3. Corbeel, Brecht. 2023, December 18. In what ways could AI serve as a model for understanding potential non-carbon-based life forms in the universe? Medium. https://medium.com/@brechtcorbeel/in-what-ways-could-ai-serve-as-a-model-for-understanding-potential-non-carbon-based-life-forms-in-6b837302853d

4. InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. In brief: How does our sense of taste work? [Updated 2023 Jan 24]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279408/

5. Mayo Clinic Staff. 2023, August 19. Traveler's diarrhea. Diseases & Conditions. https://www.mayoclinic.org/diseases-conditions/travelers-diarrhea/symptoms-causes/syc-20352182

6. Shenouda M, Enten G, Nguyen T, Mangar D, Camporesi E. 2018, October 7. Human Botfly: A Case Report and Overview of Differential Diagnosis. J Investig Med High Impact Case Rep. 2018;6:2324709618801692. doi:10.1177/2324709618801692 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6176541/

7. Libersat F, Kaiser M, Emanuel S. 2018, May 1. Mind Control: How Parasites Manipulate Cognitive Functions in Their Insect Hosts. Front Psychol. 2018;9:572. doi:10.3389/fpsyg.2018.00572 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5938628/

8. Gronstal, Aaron. 2018, August 13. Putting the Ethics into Planetary Protection. Source: astrobio.net. https://astrobiology.nasa.gov/news/putting-the-ethics-into-planetary-protection/

9. Yadav S, Sharma AK and Kumar P. 2020, February 25. Nanoscale Self-Assembly for Therapeutic Delivery. Front. Bioeng. Biotechnol. 8:127. doi: 10.3389/fbioe.2020.00127 https://www.frontiersin.org/articles/10.3389/fbioe.2020.00127/full

10. Kim, T., Lee, J. 2023, November 23. Silicon nanoparticles: fabrication, characterization, application and perspectives. Micro and Nano Syst Lett 11, 18 (2023). https://doi.org/10.1186/s40486-023-00184-9 https://mnsl-journal.springeropen.com/articles/10.1186/s40486-023-00184-9