[1.28b - General] Xenobiology Text

[Zach]

Why would you not expect an alien lifeform to have DNA at all? Every living thing that we've encountered has DNA. If that isn't true, at least every complex organism (not a virus or anything more basic).

We SHOULD expect them to have DNA, just as we should expect that they are all carbon-based.

[thixotrop]

My two cents:
DNA = Deoxyribonucleic acid
The definition of the nucleotids that form the two RNA strings are organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate.

So an alien lifeform should have a different setup of "DNA". Maybe not a double-helix and possible not made from same nucleotides. Otherwise they should resemble some organic life on earth. And because they do not, DNA is not expected.

Yeah you could say "then DNA has other nucleotids" but still is a DNA, but the D is the sugar-type, why should they have that.

[bifohe6676]

Great response by thixotrop already, but yeah, you could imagine countless other ways in which molecules form complex structures that encode genetic data, so it is indeed super weird and extremely unlikely to the in-universe scientists why the aliens' genome is encoded in recognizable Earth-like DNA and not some other way.

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Every living thing that we've encountered has DNA

Correct, and all of these living things stem from Earth, not some other planet, all life on Earth shares the same genetic mechanisms and common ancestries

So you naturally would expect all lifeforms from another planet to also have some or all of these mechanisms, but share other common genetic ancestries, most likely very different from ours, even if most likely Carbon-based (Carbon chemistry is famously complex and an extremely broad subject, aka Organic Chemistry).

A rough analogy would be languages, you can easily recognize that somebody who speaks a totally foreign language from your own (e.g. Chinese vs. English) is using stuff like sentences, questions, shouts etc. and is using their mouth to form words, but you will have totally different words for the same things, so you can not easily communicate together even though you share the mechanisms of communication.

From an outsider's perspective a conversation in Chinese sounds totally different than the same conversation about the same topic in English, right?

Now imagine e.g. Christopher Columbus landing in the Americas, should he expect the locals to be speaking his mother tongue and have no trouble communicating with them, or should he expect them to be speakig an (to him) alien language, even though everybody can easily recognize that both use stuff like sentences and their mouths?

Not sure how far you are into the story, I don't want to write spoilers here, but it is explained later in the campaign why this expectation of alien genetics is blown away by having the aliens have familiar Earth-DNA, and I really like that in-universe story explanation that also unveils more things!

[Zach]

I suppose I got severely out-classed in this battle of knowledge. Well then, is it too much to ask to put a bit more science in the text? Most of us don't have biology degrees and therefor should arrive at a similar conclusion as I did.

Thanks for setting me straight.