DNA doesn't contain enough information to replicate ANY life form!
Without context it's useless...
Let’s begin with a thought experiment...
Let's say that our sun goes supernova and to avoid extinction we humans store our DNA and the DNA of every animal species onboard a spacecraft (a kind of modern Noah's Ark) which we launch into space. With the hope that some alien species some day will find it and recreate the species which used to live on this planet.
I guess most people would think that this should work, because we're led to believe that the DNA holds all the "source code" needed to be able to replicate any species...
But does it?
It's just a coarse blueprint!
If the information stored in the human DNA can fit on a single old CD (as in not DVD or Blu-ray) because it's around 750 megabytes. Then to me it's VERY clear that most of the information needed to recreate a human body can’t be stored in the DNA...
Because I do know a lot about INFORMATION (being a software developer) and what kind of space (in megabytes) is needed to be able to store representations of different kinds of data / information (detailed enough to being able to share and replicate it). E.g. different file formats... And with this background I know for sure that it's theoretically impossible to store ALL the information needed to replicate ANY species in JUST the DNA code of that species!
That the DNA must instead be some kind of a coarse blueprint leaving out a LOT of important details. Which of course most blueprints do…
E.g. a building blueprint tells you where to place the walls, doors, windows, etc, but any details on how to construct e.g. the windows are not included in the same blueprint! Nor are any details on how to properly construct such a building…
This is because the workers who are looking at this blueprint to construct the building already have (through many years of schooling) been taught how to interpret it and how to properly construct buildings of such a type. And even they depend on other people to construct the windows…
Hence you couldn't just send that blueprint to some aliens and think that they would instinctively know how to construct such a building or know how to construct doors, windows or the right light bulb sockets, etc.
Because there is a hell of a lot more information you would need to send them before they would be able to do anything constructive with such a blueprint! Any “house” they made without the proper details wouldn’t be a place you would want to live…
Now let’s compare DNA with computer code!
I find that comparing DNA with the source code of a typical computer program (commonly called software) is a great analogy! Because one might also think that sharing the source code of a software might be enough to replicate it and run it on some alien computer…
But nope, it's NOT that simple!
Because most of the software running on your computer depends on a LOT of other parts. E.g. the software you’re using to read this article depends on lots of other software libraries being available on your computer (meaning it depends on code which is NOT included in its own source code). Such software libraries are commonly called dynamically linked libraries (DLL files on Windows).
But it doesn’t stop there, because the code of the program also heavily depends on a compatible operating system for it to be able to actually execute and display anything on the screen…
So if you want to share any software with some aliens on another planet (in terms of allowing them to replicate it): Not only would you need to share the source code for that software, but also all the source code for any software libraries it depends on PLUS the whole source code for the operating system it’s supposed to run on!
And EVEN if you shared all that, the aliens wouldn’t know how to correctly COMPILE that code…
To compile the code means to translate the humanly readable version of it (the source code) into something that a computer can understand, namely the CPU (Central Processing Unit) inside of the computer. This compilation step could be compared to a womb constructing an actual animal from its DNA.
Because to do that the aliens would also need to use the correct compiler! Since it’s the compiler which has the knowledge on how to correctly construct the “low level” computer code (which a CPU can actually execute) from all the “high level” source code.
But... what if you also send them the source code for the compiler? Well, then how are they going to compile the compiler without having an already compiled compiler...?!
Ok, to cut this short...
Basically you would need to send the aliens the whole damn computer including an already compiled compiler so that they could compile the operating system, all the software libraries and finally the program you wanted them to replicate!
And I think that this is also the case with our DNA. You can't just send them the DNA and expect them to be able to do ANYTHING useful with it! Without also sending them a whole goddamn human body for them to impregnate with the DNA and then have the human body build the replica...!
Because it's only the human body who knows how to correctly assemble a human baby! Experiments where they've attempted to put human DNA into the embryos of other animals (as in fertilizing the egg that develops into the embryo) didn't really work…
Conclusion.
My point is that there's a TON of knowledge and information inside of the cells themselves which MUST be used TOGETHER with the DNA to be able to replicate an animal!
And I don't think that you could just send over a couple of cells to solve this problem, I think you need their whole "cell society" working together properly if you want to be able to achieve anything (a.k.a. a body)…
In other words; what I am saying is that I think that to replicate an animal from its DNA you would also need to send over THAT animal! Because it's only the animal who functions as the CORRECT compiler for any DNA "source code" belonging to that species.
That DNA without the correct animal to "compile" it isn't worth much…
Further discussion:
So what kind of details could be left out of the DNA?
This is a really interesting question and I guess lots of things could be simplified or even completely left out (depending on what kind of "knowledge" the related species's "cell society" holds).
E.g. in our human society we have lots of different professions; where workers from each profession mostly have a different set of knowledge and expertise. And e.g. when we want to construct a skyscraper we need to use lots of different such workers to be able to go from a blueprint to the finished building.
Just imagine the insanely huge amount of information needed which is not described in the blueprint… E.g. all the information workers from each profession learned through years of schooling. And any information related to items placed inside the building, details about how to create a vending machine, elevator, toilet or the computer system running all the automated electronics in the skyscraper. Just the computer system is extremely advanced, yet the blueprint doesn’t specify anything about how to build a computer.
I'm thinking that maybe the DNA doesn't really have to contain all the information related to the construction and distribution of blood vessels for example… And I can probably think of hundreds of more things, but I think that I have gotten my point across already.
Hence I’ll leave this as an exercise to the reader to come up with more examples of things that the cells themselves might have enough knowledge about to construct without needing any guidance from the DNA blueprint.
Disclaimer: Everything written here is just my own opinions and not scientific facts, yet.