The biblical story of Noah and its Ark can be interpreted in different ways: As an entertaining legend, as a religious story from which lessons can be learned and as ingenious bet on the survival of species if confronted with a global catastrophe, but can it actually work?
First of all, we should take into account the historical background of the story to understand what it means: The idea of an Ark is actually older than most people think. Indeed, Sumerian clay tablets were found at the ancient Nineveh library telling the story of Ziusudra, a man who was told by one of the Sumerian gods to pack everything into a ship and stay there until a deluge caused by an assembly of gods passes. The gods apparently grew frustrated at humankind and decided to do a fresh start,but the god Enki felt sympathetic to humans and blew the whistle, so Ziususdra gathered his family and all kinds of animals, and survived in a ship made of wood.
According to this ancient myth, Ziusudra was not a farmer, nor a simple man; he was a king and indeed, if he had a wooden ship at his disposal - whether he took or built it - couldn't have been poor because wood at that time and in that region was extremely expensive. It had to be imported from Lebanon or Africa. Many stories found in religious texts have some degree of true historical background, while others are based on pre-existent traditions adapted in order to show the values that the new religion attempts to teach. This is not the the topic of this article, but it is nevertheless worth mentioning.
Over time, the story of Ziusudra and his ship became popular in the whole region: Among Accadians, it was known as the myth of Athrahasis and of course, eventually found its way into the Old Testament. Whether this was due to the popularity of the myth that turned it into a sort of "must read" story, or there was a common belief on it is another question, but it is interesting that it was a shared tradition among societies that were rather antagonistic in religious terms.
Undoubtedly it has a certain attractiveness because it is a concept as popular today as it was thousands of years ago. We see it in our religious texts, but also in novels and pictures. However, it is rather odd to find real examples of the Noah's Ark concept applied to real cataclysmic situations, at any scale.
Noah's story is one of faith and morals, and that is one of the reasons that explains its longevity and popularity beyond religious boundaries, and tells us about human mistakes and divine piety. But aside from this, the story of the Ark is a pretty thorough description of a survival technique conceived thousands of years ago in order to save both humans and what we now call the biosphere if and when a global catastrophe takes place.
What could have Noah's Ark actually saved?
Noah's story is a valuable concept as seem from many different perspectives, but taken literally and considering what we now know in scientific terms about our world and its dynamics, it falls short of what is needed to survive. For example, a flood capable of liquidating every living thing and species will likely take more time to develop and recede, and after that, even species contained in the Ark might not be enough to restart life because animals and plants are adapted to certain conditions that will almost surely have changed after the flood event because such changes are what produce mass extinctions in the first place. Plus, there are interrelations among - for example - carnivores and herbivores that are far more complex than having a pair of a male and female of each one.
The more ample and varied the ecosystem that is to be protected by the Ark, the bigger and more numerous the post-cataclysm adaptation problems will be. And to this we should add a factor of cultural and historical perspective: For Sumerians, the two biggest catastrophes that could be conceivable were a mass attack by hordes from the mountains in the north of their land (for Sumerians, mountains were akin to the modern Christian concept of hell), and river floods. In that region of the world they didn't have any experience of heavy snowfall, volcanic eruptions, meteorites, forest fires, cyclones and so on.
Thus, it is reasonable to assume that if Noah's Ark really existed, it would have served its purpose well in protecting just the living representatives of that particular, limited ecosystem. That is how it could have proved effective as a means for survival. And to that we should add that since the Middle East is not isolated from the rest of the world, even if all living things were wiped out at the time of the flood there, there would have been an influx of new living things from neighbouring regions, be them the same or different species. So, the liberation of the animal passengers and plants from the Ark would have been reinforced by natural migratory processes.
It is to be noted that while traces of deluges in the region have indeed been found, these do not extend to the whole planet, so there is no proof that a truly global or universal deluge took place.
This leads to a first conclusion: The more complex the ecosystem to be saved, the more complex will necessarily be the required Ark.
In modern terms, an Arc could be a repository, if the information required to trigger the resurgence of species is stored, be it as DNA samples, seeds, sperm and eggs and so on, or an artificial biosphere, is living, active and not latent species are to be kept. A cursory analysis of these options leads to the conclusion that the second one would likely be far more costly and complex than the former.
Similarly, an Ark managed or crewed by humans will be necessarily more complex and expensive than one that relies on full automation.
Arks could also be classified in two groups: local or global depending on whether they are designed to save the living entities of a local ecosystem or a whole planet, assuming that the planet is a closed ecosystem because if theories such as panspermia are considered, then the definition of local and global should be reconsidered.
In case that proof is found of ecosystems larger than one celestial body and spanning several ones within a solar system or even beyond, as unlikely as it might seem now, an ark capable of saving it all would be proportionally big and complex.
Another conceivable type of Ark is one destined to save the cultural legacy of a whole civilization or species.
And another way to classify Arks could take into account the media or environment in which the Ark would eventually serve. Traditionally, Arks are conceived as floating vessels, and more recently, as spaceships, thanks to science fiction. But arks can take any form suitable to guarantee survival: an Ark could be placed in a Zeppelin or aircraft, inside a passing asteroid, it could be a submarine or even a cave, and island and so on.
Just an Ark or a fleet of Arks?
If the mission of such a system is to save a world by guaranteeing the survival of its living species and cultural legacy, it would be smart to improve the odds betting on more than one Ark, if possible. That is, even better than having one is to have many Arks, be them subterranean deposits, spaceships or whatever. These arks could be sent each one on its own, or put to act together in coordination.
It would also be better to store in each one of those arks a full “copy” of the world that must survive, and no portions of it. That is, instead of placing all plants in one Ark, all animals in another and so on, it would be more sensible to place al sorts of plants, animals, etc. in each ark because if one fails but copies are redundant, then survivability would be better insured.
There are more aspects to consider in the construction of an Ark: Technology, politics, the design of the mechanisms for the eventual recovery of the stored biosphere and even the panic of people that might sense that they will be left behind are significant factors that require extensive treatment, so we will discuss them in further articles.
Problems that might appear during the construction of a "Noah's Ark"-like survival shelter.
Recovering and reconstructing the contents of an ark.
Surviving survivors: What to do with people that survive a catastrophe but are dangerous to others.
How long would it take to turn people into brutes?
What if we have to play the part of Mt. Ararat in an interstellar, UFO survival situation?