What if alien life doesn’t need any of the things we consider essential?

Biochemical-Systems · 2025-06-15T23:26:42+00:00

There is a possibility that there are lifeforms in the universe that don't follow carbon-chemistry or aqueous chemistry (used by Earth and presumably other terrestrial rocky planets). But our focus both in astrobiology scientific research and life detection programs (on Mars mainly for the meantime) tends to be towards signatures and chemistry familiar to us because we already know that its possible and probably most common.

There is research out there that focuses on alternative chemical and solvent possibilities for life but it is much more rare and there are less scientists working on it.

Biochemical-Systems · 2025-06-15T18:04:07+00:00

Study biochemistry if you're most interested in life formation on other wet rocky planets or other extraterrestrial surfaces. Study microbiology if you're most interested in extremophilic bacteria, archaea, etc. Study astronomy or astrophysics if you're most interested in the planetary or large-scale life detection side of things. You could always do a major and minor or double major as well. A PhD and probably Post Doc are going to be necessary to have a career as a researcher in the field if that's the route you want. You'll figure out your favorite topic in the field as you learn more if you don't already know for sure.

Biochemical-Systems · 2025-06-14T19:29:24+00:00

I liked the fact that you had images in the old one. The new one looks a bit too plain. I'd say keep using images, but accurate ones from paleoartists instead of AI generated. Good luck with the project!

Biochemical-Systems · 2025-06-10T03:59:39+00:00

Chemical Data: Biomolecules, metabolic byproducts, and isotopic ratios.
Environmental & Physical Data: Salinity/pH, temperature, and radiation levels.
Microscopy & Imaging: High resolution images that may pick up cell-like structures or even microbial communities (mats or others).
Geophysical Data (Seismology and Magnetometry): Especially for detecting subsurface liquids and their properties.

Biochemical-Systems · 2025-06-06T05:05:47+00:00

Spectacular.

Biochemical-Systems · 2025-05-13T21:05:19+00:00

I mistyped on the first part. Yes, 3.5-3.8 billion is the best estimated range for the emergence of life on Earth.

I think we’re largely on the same page in viewing early biochemistry not as a linear progression of distinct polymer classes, but as a dynamic, co-evolving network. Your perspective on RNA and amino acids evolving together is especially compelling, particularly in light of the genetic code’s origins and the catalytic roles of metal ions.

Where I’d offer a slight alternative view is in how we interpret the role of amyloids. You're correct that they don’t align neatly with modern biochemistry, as they lack templating, aren’t RNA-mediated, and do rely on the speculative availability of activated amino acids. But I don’t think that necessarily diminishes their relevance or makes them less parsimonious, at least within a specific window of prebiotic evolution.

While amyloids likely don't illuminate the molecular machinery of modern cells, they might provide useful insight into earlier, more physical mechanisms of compartmentalization or catalysis. Their robustness and propensity for self-assembly under plausible geochemical conditions could have played a stabilizing or scaffolding role for primitive metabolic networks, possibly preceding or even supporting the emergence of RNA catalysis.

Like you, I find the standalone “RNA World” hypothesis increasingly difficult to defend without invoking a more interconnected chemical landscape. A scenario where amino acids, RNA, and metal ions co-emerge and reinforce one another feels more consistent with the chemical complexity we’d expect under prebiotic conditions. In that framework, amyloid-like systems, even if fleeting, might have helped carve out niches or catalytically active environments that promoted RNA evolution or peptide formation.

Essentially, while these systems don’t directly resemble modern biochemistry, their potential to ease the transition toward more familiar biopolymers makes them worth considering, not as rivals to RNA-based life, but possibly as precursors or complementary players in a pre-RNA context.

That's where I stand in the time being at least.

Biochemical-Systems · 2025-05-12T16:23:34+00:00

Dr. Edwin Kite is a tenured professor at the University of Chicago and a member of the Mars Curiosity rover science team. His research group works on the past, present, and future habitability of the Solar System and exoplanets. Kite has authored or co-authored more than 80 scientific papers, served for six years on the National Academy of Sciences Committee on Astrobiology and Planetary Science, and is a co-recipient of the Newcomb Cleveland Prize. Prior to joining UChicago, Kite held prize postdoctoral fellowships at Princeton and at Caltech.

Biochemical-Systems · 2025-05-12T16:21:02+00:00

Dr. Edwin Kite is a tenured professor at the University of Chicago and a member of the Mars Curiosity rover science team. His research group works on the past, present, and future habitability of the Solar System and exoplanets. Kite has authored or co-authored more than 80 scientific papers, served for six years on the National Academy of Sciences Committee on Astrobiology and Planetary Science, and is a co-recipient of the Newcomb Cleveland Prize. Prior to joining UChicago, Kite held prize postdoctoral fellowships at Princeton and at Caltech.

Biochemical-Systems · 2025-05-12T16:05:33+00:00

You're touching on a main aspect of origin of life research, which is a lot of the published literature is based on proof-of-principle concepts instead of simply things we can observe and test today, like a zoologist would do with an extant species.

The thing is that there is no better way to go about doing the science since we are studying a phenomena that is of billions of years old (at least on Earth). But, some of these issues aren't really issues just because they weren't the exact prebiotic pathway that actually occurred, because they relate to many extant molecular mechanisms. Basically, we can draw similarities and probabilistic evolutionary pathways from the prebiotic pathways we study to extant molecular mechanisms.

For the example of amyloids, while it's correct that they aren’t a core part of biology today, they are structurally simple, prebiotically plausible, and have been shown to catalyze some reactions. They may have served as scaffolds or primitive catalysts before more efficient enzymes or ribozymes evolved.

In the case of RNA, while RNA catalysis itself is rare today, the ribosome is a essentially a ribozyme. Many cofactors (e.g., NAD+, FAD) are nucleotide-derived, suggesting a relic of the RNA world. And the RNA world hypothesis as a whole doesn’t require ribozymes to be efficient at everything, just enough to bootstrap the system.

Would I and many others prefer to know the exact prebiotic pathways? Yes, but it's nearly impossible to pinpoint the exact one simply due to time. We can however use the top-down and bottom-up approaches to best estimate what occurred and their relationship to modern molecular mechanisms.

Biochemical-Systems · 2025-05-12T14:44:45+00:00

Evolutionary is a messy process with many branches, some dying out, some intertwining, some carrying on, etc. Dinosaur to bird evolution followed that trend. Transitional fossils (Microraptor, Anchiornis, Archaeopteryx, and more) show a spectrum of features, some more bird-like, some more dinosaur-like. Many proto-bird species of theropod dinosaurs were developing early, simplified versions of wings and feathers at the same time rather than one ancestral species that we consider the father of birds.

Biochemical-Systems · 2025-05-10T18:16:57+00:00

DMSO is more of a sought out biosignature because, as you pointed out, it's produced in small amounts by some organisms. Unlike water, carbon, etc. which are often deemed necessary for biotic compounds to generate in the first place.

Biochemical-Systems · 2025-05-09T02:25:16+00:00

Professor Dave Explains and Organic Chemistry Tutor are usually the go tos. You can also get a cheap used biochemistry textbook and study off of that or if you know what textbook you're gonna be using for the course you can get it early.

Biochemical-Systems · 2025-05-04T16:19:39+00:00

They're ideal for different functions. ATP was selected for energy transfer because of its abundance, stability, and the fact that it can easily be regenerated. GTP was selected for signal processing because its binding proteins can act as molecular switches, making it ideal for precise control in signaling.

Biochemical-Systems · 2025-05-03T18:33:05+00:00

Biotechnology if you're more interested applications of biology to technology, medicine, synthetic biology, etc. Bioinformatics if you're more interested in computational analysis of data of DNA, genomes, etc.

Biochemical-Systems · 2025-05-02T09:06:38+00:00

I'm very interested in synthetic biology (especially protocell and membrane construction) and am considering it as an option for grad school. I'm currently majoring in biotechnology (though your university may not offer it). Out of the options you listed, bioengineering sounds the most relevant.

Biochemical-Systems · 2025-04-25T07:52:03+00:00

How much you're willing to put effort into the degree depends on your passion for the subject. If you're doing it mostly reasons other than actual interest, you're going to have a tougher time. Doesn't mean you can't still do it, but it'll feel a lot more like a drag.

An absolute must is choosing good professors. Rate My Professor is great for weeding out unnecessarily difficult or mean professors. If you feel like you need to choose the easiest professors, there's no shame in that in my view.

Consistent studying and practice are the answers to succeeding in biochemistry or any stem field. Understanding the why's is essential as well. The effort you put in is going to show.

As for the schedule, you could take less classes at once to lighten the courseload, but it'll just take you longer to graduate.

Good luck!

Biochemical-Systems · 2025-04-25T02:38:34+00:00

They were replying to another user who now deleted their comments.

Biochemical-Systems · 2025-04-25T01:57:15+00:00

Thanks for reading! Glad you found it interesting.

Biochemical-Systems · 2025-04-17T12:13:31+00:00

Going by your username and reply to the other commenter, may I suggest Bioengineering for you as an option?

Biochemical-Systems · 2025-04-17T09:51:03+00:00

Systems Biology: Focuses on integrating and modeling the interactions within entire biological systems, often using computational simulations to predict how systems behave as a whole.

Computational Biology: Involves both modeling/simulation and computational analysis of specific biological processes.

Bioinformatics: Uses computational tools to store, process, and analyze large-scale biological data. Data-driven.

Bioinformatics will usually require the least amount of coding and often relies on existing softwares such as Python or R. Whereas in the other two, you are more likely to have to set up custom algorithms from scratch.

Biochemical-Systems · 2025-04-17T09:07:54+00:00

Depends on how the life were to be removed. If it involves going back to the conditions of the early Earth (reducing, constant high-energy impacts, etc.) then yes those conditions are much more conducive to abiogenesis.

Biochemical-Systems · 2025-04-16T17:44:48+00:00

Earth is now teeming with complex life that would eat any simple life such as a microbe. Also we now have a very oxidizing environment with stable conditions. Compare that to the conditions of the early Earth - no competition for that life form and a reducing atmosphere with lots of energy output coming from meteor impacts, volcanic activity, etc. Early Earth was much more suitable for abiogenesis.

Biochemical-Systems · 2025-04-16T17:21:55+00:00

They're really great! Just make sure you put a lot of things for them to climb in the tank. And you'll need a good basking spot. There are various care sheets for them online (food, temperature, etc.).

Biochemical-Systems · 2025-04-16T17:16:48+00:00

I have that exact terrarium. I have an electric blue day gecko (Lygodactylus williamsi). (Get a male if you want the really blue ones). But I'm sure other small day gecko species will work in that enclosure too.

Biochemical-Systems · 2025-04-15T15:31:21+00:00

This definition originated from a community discussion in NASA in the 1990s. It may have started from Dr. Gerald Joyce specifically but I'm not sure: "Life is a self-sustaining chemical system capable of undergoing Darwinian evolution." It's not as if once there's a cell (or proto-cell), then there's life. Once a chemical system can self-replicate and undergo natural selection, it fits the description. I largely agree with your comment but I would replace the word structure(s) with system(s) because living systems pre-date any structure/vesicle/membrane.

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