Far in the future, when we have the resources and ability to travel all over the galaxy, we will, no doubt (hopefully), finally encounter alien life. The chances of us being the only planet with complex life is very very slight.

Each planet will have unique lifeforms dependant on the planet's particular history. Some planets will have,predominantly, carbon based life forms others, well other based life forms.

Many Previous questions and their very interesting answers have suggested that organisms may possibly develop, recognisable limbs, eyes, mouth, heads etc based on the fact that 'nature' chooses the most efficient option. We may not recognise the beastie but we will know from which end to run from.

There is also the theories of Speciation and Convergent Evolution. Mourdos explained that Speciation is when evolution produces different branches even when under similar/exact conditions. Convergent Evolution as I understood it, is where creatures will evolve along similar lines given the same influencing factors even if they are not from the same family type. With the advent of more and more advanced techniques and classification distinctions eg DNA and more and more fossils being found we have found that we have often classified creatures in the wrong family based on presumed similarities. Eg I recently found out that Homo Habilis is no longer considered a Homo (by the majority of scholars), rather it is now an Australopithicus habilis. Simply put, is the Tomato a fruit or a vegetable?

I have taken this as to say, there could be a/many planet/s out there that have evolved a carbon based life form similar to earth's early history.

Just using the jurassic as a clear example.

There would be some obvious speciation, but at the same time there could be some creatures that have evolved along convergent evolutionary branches to either Earth or other planets with life that we don't know about yet.

So, say you have a planet with SOME similar life forms to Earth, instead of dying out in some mysterious cataclysmic event, on this planet the dinosaurs survived. They continue to evolve. Any future development they have, us earthlings wouldn't recognise.

But, if we were to travel to this planet that was only a short time into this new alternate evolutionary path, say a few hundred thousand years. We would still be able to recognise an alien life-form if it co-evolved along similar lines to a Stegosaurus or Brachiosaurus. If we were to travel to a planet that that had a similar evolutionary history to Earth, before the big extinction event, then we might recognise a lot more. Not all, but a fair few.

After visiting many many thousand planets and encountering many various evolutionary speciation and co-evolutionary branches, one would soon have a vast knowledge base to draw from for creature identification. Besides from seeing claws and large canines, and decide it would be better to run, you would be able to see what characteristics of the creature, and deduce statistically what type of creature it was, maybe some basic creature habits, and the possibility of what other types of creatures may be around as well. This would be useful for animals that looked carnivorous but where actually herbivores and vice versa.

To get some uniformity in naming creatures and plants across the galaxy and universe you devise this guidebook. No need having completely different names for a creature that is similar but unique to every planet to a domesticated cat on 30 different planets. Rather you could just call it Terran Felix... Um, domesticus or Andromeda Felix domesticus (I know I know Andromeda is a galaxy, or a ship depending on who you ask). They wouldn't be an exact family match, But typically humans are lazy, and don't want to create a new name for creatures (have you seen some of the absurd names out there?). So this naming would be more along the lines of, this is the closest creature to a cat on this planet, so we will name you Andromeda Cat. Then any creatures related to Andromeda Cat would be in the same family name group...

Now here comes the Original question. Could you, or your great great great great....great great grandchildren compile such an intergalactic encyclopedia of creatures, habitats, and other such characteristics (answer appears to be yes) and use this as a guide for successfully exploring new world's (still to be decided)? If I am missing something, What details can be added to increase the likelihood of such a guide being useful?

The fuller the guide, the more likely you would get a successful basic description of beasties you may encounter. There is room for humorous (to write and read) incidents where the guide's readout was not accurate or not all pertinent descriptors are entered resulting in an inaccurate readout!

Further edits to Clarify thanks for letting me get home from work before putting this question On Hold.

Ok, So it seems that in the few comments this question has garnered, there is a general consensus that a compilation of different animals/plants would be possible. Useful? Not certain yet. I will try and explain what I'm after a bit better.

The linked question about Xenotaxonomy is great. But it is focussing more on the names and naming process - taxonomy. That part of the question is sort of answered already. It's possible, people may have different naming conventions, but it is possible.

What I'm really focussed on and maybe wasn't clear (at all), isn't so much being able to identify the name of the beasties chasing you but rather their behaviours. Knowing their name would be very useless when being chased. But knowing that the beastie chasing you typically, across the explored galaxy, hunts in groups would be nice information to have.

I'm rather interested in saying,

well this beastie (on new planet) looks a lot like this other group of beasties from this other planet, Planet X (or maybe from a large group of different planets - will just work with one for simplicities sake). Planet X beasties like to keep their victims alive while they transport them to their nests/caves/dungeons. There is a high probability that new planet beastie would be somewhat similar and that my missing explorer friends are actually still alive and I have a short window to try save them.

This New beastie also has the slimy skin of planet X beastie and they tend to need to immerse themselves in water frequently. They prefer to weigh down their victims and let them rot underwater for a few days before consuming them. Their victims are not always dead when they are submerged. Now you know roughly were to start your search for your missing friends. They might already be dead and eaten, they might not be, but it's a start.

Or, In every planet this sort of beastie has been encountered (in various unique forms), it had poisoned saliva that it would inject into you when it bit you. You have on average 24 hours to live. You may only have 2, or maybe a few days. But you know you need to look start looking for the galactic healers asap.

This sort of beastie with the large eyes, generally has great vision and is a great hunter, but sudden changes in brightness disorient it. Great tip for getting away.

This beastie with the massive horns is typically absolutely harmless. Except for the brief window of time it is on heat/musth. Then it is a raging monster from hell.

So this guide wouldn't so much be about naming the beasties, but rather listing the characteristics of their hunting/mating/ and general habitats and habits.

Yes, each creature is unique. And the likelihood of it having the exact same such characteristics are slim to none. But statistically, if everytime you have met and studied a creature from various planets that met certain descriptions, say trilobites, and every single one of them had the same characteristic, or habit, say burrowed under the mud. Then you could very well expect your trilobite-looking beastie on your new planet to... burrow under the mud.

So, what I'm asking is? After this clarification, would my encyclopedia/taxonomy (ET) guide to the universe be as useful as I'm hoping? or am I still being too optimistic about the differences and similarities in extra-terrestrial life?

I would expect mistakes and unknown differences in species. But is the ET Guide to the Universe a general useful guide to not getting eaten? or a professor's life's work of no real-world use? What can said professor do, to make his life's work more relevant on an immediate need-to-know sort of level that an explorer or scientist would make use of his guide? The professor wants his work to save life's, not collect dust on a bookshelf.

  • 4
    $\begingroup$ What you describe isn't coevolution. Coevolution is when more than one species evolve together in a way such that the evolution of one affects the evolution of the other. What you have in mind is convergent evolution, in which multiple species independently develop similar trait(s), usually because those traits are beneficial in their particular environment. Hence why, for example, whales and fish (which are quite far removed from each other) have an outwardly remarkably similar appearance. $\endgroup$
    – user
    Sep 5, 2016 at 8:44
  • $\begingroup$ Our modern names for species etc are based on how related they are, genetically. Your system would require to turn back to times when we didn't know about evolution, and was only able to use phenotype. Not usable for any science in modern meaning. So what's the point? Probably scientists would be the first one to visit new planet anyway. $\endgroup$
    – Mołot
    Sep 5, 2016 at 10:03
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    $\begingroup$ What you are trying to come to grips with is called taxonomy. This is the science of classification of animals and plants. Convergent evolution doesn't necessary play a big role in taxonomy because organisms are classified in terms of their distinctive characteristics and their 'family' relationships. The result will be an intergalactic taxonomy not an intergalactic encyclopedia. There will, of course, be popular guides. $\endgroup$
    – a4android
    Sep 5, 2016 at 11:48
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    $\begingroup$ nice question. There is everything positive - it can be done, it can be useful. Your encyclopedia is subset of the Model thing from that answer worldbuilding.stackexchange.com/a/41975/20315 . Your encyclopedia of everything should have translator - and translation should depend on knowledge of person using it and place where they are, goals they are using it for. This naming convention you come-up with is ok, although being fixed it looses some value, specially where are enormous amounts of objects, which names are mostly numbers and even if they are names they do not talk to you $\endgroup$
    – MolbOrg
    Sep 5, 2016 at 21:43
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    $\begingroup$ What you want is comparative taxonomy. Simply extending taxonomy to cover the range and variation of alien biospheres. There could even be a taxonomy of convergent evolution, which span across lifeforms of multiple biospheres. Already palaeontologists can reconstruct creatures from finding a few fossil parts. Perhaps what you looking for is a comprehendium of possible lifeforms and their modes of existence. $\endgroup$
    – a4android
    Sep 6, 2016 at 4:59

1 Answer 1


First, I wouldn't care about naming. Modern naming is pretty random and arbitrary. There is high probability that knowing name of a creature will tell you absolutely nothing about said creature. Even if you limit yourself to our planet.

There is also high chance that if complex life is as common as you say, that scientists will use same naming scheme as they use for stars and exoplanets : numbers and symbols. Probably with first few symbols being same as planet they are from. Only after normal people start to hang around alien life would alien creatures get "recognizable" names.

As for classification, there would be two ways to classify new creatures. First would be "forest of evolutionary trees" instead of single tree. Each planet will most probably have it's own evolutionary tree. Second classification will be based on niche the creature inhabits. It will be extremely easy to recognize creatures that are similar to trees, "herbivores", "carnivores", "bacteria", "aquatic", "land-based", etc..


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