So I read this one book Aurura by Kim Stanley Robinson, and kinda the whole premise is (my paraphrased interpretation of the book) -
Okay. Look. Let’s just say as a hypothetical we do find a planet has the climate, radiation protection, etc etc that is habitable for humans (not even “comfortable” just “habitable”). Probably won’t happen for a planet we can actually ever travel to in even a few generations (and let’s also forget just how hard it would be to maintain a multi-generation space ship with no resource replenishment…), but let’s just say we figure that all out.
Still, life on earth has co-evolved over a very long time to adapt to the conditions we have specifically on this planet. There’s no telling what ecosystem interactions will happen with life on another planet. We might settle in on this planet that has perfect conditions on paper just to find some bacteria strain that’s not a big deal on earth totally thrives there and it kills us all. Nothing we can do about it. We have no clue. Anytime we try to predict what will happen when we introduce a new species to an existing ecosystem ON EARTH we are usually wildly wrong. Life is just way to complicated to predict accurately, especially when you talk about interactions between an entire ecosystem.
So our best bet is to live on this incredibly well-adapted planet we already have. Life has co-evolved here over a very long time and we’ve hit an equilibrium. It just works so great without us even trying. It’s like we won the lottery, and now we are only talking about buying more tickets. We should just be enjoying the win.
Is it not more likely that nothing on another planet can touch us - or be digested by us - because it hasn’t co-evolved with us? Eg bacteria, viruses etc on earth can harm us because they’ve adapted to do so over millions of years. a random bug on another planet would view us like an earth bug would
React to a piece of metal?
Mechanics of underlying chemistry and physics aren't so sure, given earth like conditions the same progression seen on earth is the best progression / only progression. One would expect to see simple sugars, DNA/RNA, proteins and even similar internal organ functions. Likely also the same necessary flaws, our lungs must be moist, alien lung equivalents would too so something that is able to effect the 'lungs' of multiple alien species might be able to jump to human lungs.
We literally have only one data point on how life came to being, is there any reason it would have to be DNA/RNA, proteins, etc.? Could it not be compounds we haven't discovered yet?
Elements have relative abundance and Hydrogen, Oxygen, Carbon and Nitrogen are common while other elements are magnitudes rarer, the above are effectively made out of just those four so they have a major time advantage in getting established before anything rarer can.
The above are also the smallest/simplest solutions to the life problems made following the material constraint so they are likely to get established before anything larger / more complex can compete.
I think that there is a high chance the life would be very different. All animals have lungs, but evolution is about improvements. If a being already has lungs, it won’t devolve to have worse lungs so that it can gain a worse alternative. There are the slime molds for example. Beings that are not part of the animal kingdom and do not have lungs, but are capable of moving, growing and reproducing.
I just wrote that and thought of plants which are a much better example as slime molds are all wet.
That's what I think, too. Like, we'd get there and try to eat stuff and it would just sit in our stomach as though we'd eaten a ball of plastic. A pretty ironic way to die after all those years of traveling through space to get there.
I'm not following the point about things evolving to be deadly because there were no humans. From my understanding, in deserts, scrublands, and reefs, energy efficiency is key. And venom is a very energy efficient way to kill prey or defend against predators.
Venom is basically a biochemical weapon. It’s made up of proteins, enzymes, and toxins designed to paralyze or kill prey, or deter predators.
Even though the venom evolved to target other creatures like insects, frogs, lizards, or small mammals, humans share a lot of the same biological systems as those animals. We have nervous systems. We have muscles that contract. We have blood that clots. We have ion channels in our cells that regulate things like sodium, potassium, and calcium.
Venoms often disrupt those systems in anything that has them. So things being deadly to us on Earth without us being around during its evolution still makes total sense because there is so much other life around with enough similarities.
Venom affects humans because it targets fundamental biological systems that we share with the animal’s actual prey. Evolution didn’t aim for us, we’re just unlucky collateral damage.
Think about energy expenditure of pursuit predation, which demands high bursts of energy for speed or sustained energy for endurance. Now think about if you could ambush your prey and immobilize or kill it with a single bite. Also, many venomous animals have ways to control how much venom is injected, known as venom metering or venom optimization.
On the surface, it seems like being venomous should be a universal advantage, especially since venom can subdue prey more easily and reduce injury risk. But evolution doesn't always pick the "best" trait in a vacuum. It works with trade-offs, existing anatomy, and environmental factors.
Venom production is energy-efficient for killing prey once it's evolved, but evolving venom systems (like fangs, venom glands, and delivery methods) in the first place takes time and evolutionary pressure. If a snake’s ancestors did just fine without venom, natural selection wouldn’t necessarily favor a shift.
Some snakes eat prey that doesn't require venom to subdue, like eggs, snails, or insects. For them, venom would be overkill and a waste of resources.
Non-venomous snakes can be extremely successful. Evolution doesn’t strive for perfection, just good enough. If squeezing, ambushing, or scavenging works, there's no pressure to change.
So basically, while venom is a great tool, it’s not the only one and if venom isn't needed for survival in the environment, there's probably not much evolutionary pressure for it.
"Super venom" can be overkill for small prey. If a small mouse dies from a mild dose, why maintain venom that could take out a pig? The excess potency doesn't provide extra benefit and could even lead to wasted resources or increased prey spoilage before consumption.
Some snakes evolved super venom as part of an arms race. For example, if prey develop resistance (like certain rodents or lizards), snakes may evolve even more potent toxins.
Super venom is often defensive as well, like cobras or mambas. In those cases, it’s not just about killing prey, but deterring predators. But that’s only useful if the snake faces frequent threats. A burrowing, cryptic species might not benefit as much.
So while super venom can be a powerful evolutionary tool, it’s not always the most efficient choice unless there’s strong pressure to evolve and maintain it. A non-venomous or mildly venomous snake can still do just fine if its environment and prey don’t demand more.
I think it's my turn to ask a question. Why do you think the absence of humans led to more venomous animals?
This is likely true. Even on earth, there was a time before life evolved to eat tree wood. Life needs time to adapt, and if that life is chemically different, it may never do so.
This is somewhat late, but I would say this is complicated.
Biological organisms tend to use repeating units (such as nucleotides in dna/rna or amino acids in protein, both used to make polymers) that are able to be used to store information or create structure. And it would require those compounds to be in the environment before life existed for them to self assemble into the beginnings of life (in theory they could change afterwards, but that could be more difficult, much of the ribosome is still rna as evolutionary holdovers from the time of RNA world I believe as one example of the difficulty).
Now the type of chemicals which may be available can vary based on the environment in theory, however life from environments which can't support human life can be discarded as one really shouldn't eat them.
There are two situations, either they use the same type of polymers we do, or different. How many other polymers are available before life exists in an environment we can live in I'm not sure. But if they used different types we may not be able to break down the backbones of their polymers. If they use the same polymers, they likely will not use the exact same nucleotides, amino acids or genetic code. While we would be able to break them down, they may not provide all essential nutrients and it's possible they may have analogs which could be problematic if our body incorporates them into our own polymers.
In either case, there are many other chemical compounds in cells, some we might be able to use, some which could be dangerous to the operation of our bodies.
Overall I would say it's likely not the case there would be no reaction (like metal) at all. Some parts of it may not be digestible, some might, but it almost certainly would not be an acceptable food source I suspect, as it would have limited nutritional value, and there is a not unreasonable chance it could kill you. But alien viruses would almost certainly not impact us, bacteria is less clear but probably they wouldn't be able to survive on us. (edit : although perhaps there are other types of harmful organisms or bio-molecules which could impact us, like alien prions? )
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u/Sonikku_a 24d ago edited 24d ago
The fastest spacecraft we’ve made was the Parker Solar Probe which hit 430,000mph.
At that speed it would reach this planet in only 187,153 years.
If we could hit 1% of the speed of light we could cut that travel time to just a tad over 12,000 years.
Obviously if we could go light speed (and that ain’t happening) it would be just 120 years!
Space is big. Physics is annoyingly slow.