Human origin debate (Aidus)
The debate over the origin of humanity in the Aidus system is ongoing. The Belvisajine Inquisition of the late Forgotten Age in essence reset the historical record of civilization in the system, driving those who remained opposed to it to concern themselves more with their own survival than the survival of documents pertaining to their common heritage. During much of the First Age as well, the Drevnian Divinity systematically purged any account of history and scientific thought that did not align with their Divinist ideological position. As a result, throughout the post-Drevnian period of the Second, Third, and Fourth Ages, very little remains known concretely of the origin of humanity or even of the Forgotten Age itself, hence the nomenclature.
There are two scientifically plausible explanations pertaining to the present existence of humanity in the Aidus system. The proponents of these theories are broadly aligned under two camps: those that support the Zemaian migration theory and those that support the Orbalian homeworld theory. The former theory holds that humanity actually developed as a species on a distant planet, becoming technologically adept enough at a certain point to travel across interstellar space and settle in the Aidus system. The latter theory sustains that humanity is native to the Aidusal planet Orbalia, having developed into a species there and later expanding to the other planets of the Aidus system upon achieving the technological ability to do so. While evidence exists for both of these theories, the majority of academic archaeologists and historians in the contemporary Fourth Age tend to hold that the known quantities of the Forgotten Age are most consistent with the circumstances of a high-technology human beginning in the Aidus system, and thus, most consistent with the Zemaian migration theory.
A third theory of human origin is also prevalent in the Aidus system, but has little academic acceptance: the Seeding theory, also known as the Xeno-Creator theory. Under this theory, humanity was transported to the Aidus system by an unknown and highly advanced alien civilization. Whether or not humanity was created by these aliens is a matter of divergence among those who support the theory, with some believing that humanity arose on one planet and were selected by the aliens for the Seeding, whereas others believe that humans were the willful creations of these aliens. As the Seeding theory tends to align with the concrete evidence in favour of the Zemaian migration theory, it has not been conclusively rejected. However, the involvement of an alien species in the origin of humanity is considered by a majority of historians and archaeologists as mere conjecture, with the pressure in favour of said conjecture coming from the longstanding tradition of the Drevianic religions.
Zemaian migration
The most widely accepted theory, the Zemaian migration theory posits that humans are not native to the Aidus system. The original human planetary system, sometimes referred to as the Zemais system, is presently unknown, though several candidates have been identified. At some point in the development of the human species in the Zemais system, the technological circumstances of that civilization reached a point at which interstellar travel became possible. There is much speculation as to the motivating factors for such an undertaking, but this speculation is largely held to be mere conjecture. The circumstances of the migration itself are even less accessible to deduction, regarding whether or not the transit between star systems was undertaken with so-called "generation" or "sleeper" ships.
Circumstances
Motivating factors
Most proponents of the Zemaian migration theory posit that the voyage itself must have been motivated by the conditions of living on the original human home planet or in the home system due to the significant risks associated with making that voyage. There is much conjecture as to what would have been so significant to the quality of life on the home planet or home system, and a number of theories can be deduced from the technological capabilities of the Drevnian Empire based on archaeological and historical evidence.
In holding that the technological abilities of the pre-migratory Zemaian peoples were at least on par with the Drevnians, the situation in the original human star system was likely impacting not only the quality of life on the home planet, but the solar system's space more generally. The Drevnians were known to have possessed the ability to move freely about interplanetary space and even inhabit it through the use of Pseudogravity on artificial satellites. The number of known astronomical phenomenon which poses a risk to anyone in a star system's vicinity is innumerable, and as such, it can be deduced that the Zemaian migration could have been motivated to such a phenomenon. The planetary characteristics of Orbalia suggest, in light of the migration theory, that Zemais itself was of similar size and solar flux. The number of astronomical phenomena which could impact the surface habitability of the planet is also innumerable, and as such, when cross-referenced with the phenomena that would also impact living conditions in interplanetary space, a number of key candidates can be identified.
One of the most widely publicized and popularly accepted theories involves the outright destruction of Zemais as a planetary body; i.e., the planet was "fractured" in some significant sense, so as to make the interplanetary space within the vicinity of the planet dangerously unnavigable and furthermore unsuitable for pseudogravitationally-assisted habitation. The impact that the fracturing of an entire planetary body of roughly Orbalia's size would have on surrounding planets would also be significant, as depending on the nature of the fracturing, these neighbouring planets could be atmospherically bombarded by rogue, newly-separated pieces of the original planet. However, a key criticism of this deduction is the nature of such a "planet-cracking," in that the amount of energy necessary to enact such a scheme would be so immense that it was likely beyond the technological capacity of the Drevnians. Hence, a popular variation of this planet fracture hypothesis is that a smaller planetesimal, such as a natural satellite or a series of asteroids, would be used as weapons, i.e., tugged into unstable orbits capable of generating debris fields that would render space-habitation impossible.
Another popular hypothesis involves the star of the Zemais system, as variations to a star could also have potentially major impacts on the habitability of an entire solar system. It has been suggested by some that a supernova may have been responsible for pushing the human species out of its home solar system, but there are many factors which could render this hypothesis unlikely. Most critically, few supernovae in the neighbourhood vicinity of the Aidus system possess the characteristics of a singular star such as Aidus undergoing a supernova within the last 200,000 uecs. The biological markers of human beings, as well as the theoretical decision to colonize Orbalia, imply that the species developed on a planet orbiting a single star, as likewise, very few exoplanetary systems have been identified to possess potentially habitable, Orbalia-like worlds in the first place and almost all of them can be concretely evidenced to orbit a single star. Another star-related possible phenomenon is the impact of a superflare on the Zemais system, but the technological capacity to recover from such an event and then plan to exit the star system because of it would likely exceed the technological capacity needed to adapt to such future scenarios. Hence, many star-related hypothetical motivations for leaving the Zemais system are on somewhat less deductively concrete grounds than Zemais-specific theories.
In all cases, it is considered very likely that one of the most critical motivating factors for a departure from the Zemais system was induced by societal pressures among the Zemaian peoples. As demonstrated by the migration of the Podchinic cultures from Orbalia during the emergence of the Drevnian Divinity in the late Forgotten Age, human migrations are likely to be triggered just as much by human causes as environmental ones. There exists a possibility, then, the Zemais system remains wholly habitable to human civilization, but that the individuals who undertook the migration felt it was necessary for them to do so, in that the risks of the voyage were outweighed by the risks of remaining in their home star system. The largest issue with this hypothesis is the puny number of candidate worlds that possess the characteristics deduced to be requisite to both human physiology and Orbalian-adjacent planetary conditions.
Interstellar transit
Those that support the Zemaian migration theory have little to no evidence of the migration itself. What is believed of the migration has been largely supplied by deduction from the evidence that is present. Especially important to the Zemaian migration theory is archaeological evidence, or rather, the lack of evidence of pre-technological sophistication in human archaeological sites. Most notable are the ruined cities of Meddon Spulcre and Tristen on Orbalia, which are the oldest known pre-Belvisajine ruins in the Aidus system. Both of these archaeological sites exhibit technologies which are not distantly related to many used in the contemporary Fourth Age, meaning that no earlier evidence of a pre-nuclear theory human civilization remains.
The Zemaian migration theory thus holds that humanity arrived in the Aidus system approximately 120,000 uecs before present, which is roughly 18,000 uecs before the foundation of Aetarlux and the beginning of the First Age. Given the average human lifespan of 5,000 to 6,000 uecs, this dating scheme represents a maximum of four generations of separation between the first humans in the Aidus system and the founders of the Drevnian Divinity. Due to the extreme scrutiny of the Belvisajine Inquisition in the "erasure" of human history, very little is known of the Forgotten Age, and thus, even less is known of the circumstances of humanity before their arrival in the system. A number of deductions can be made with regards to the circumstances of the migration, however, especially if one considers the technological capabilities of the Drevnian Divinity at least at par with those who undertook the migration.
The most critical facet of the migration is the importance of risk in the transit between star systems. In identifying the exact risks of the transit, a number of aspects must be considered. Firstly, the question of whether or not the migration was undertaken with generation or sleeper ships has a crucial impact on the risk analysis of the transit itself. In a generation ship scenario, where human beings were "awake" for the journey, the long voyage through interstellar space was carried out over the course of multiple generations of individual human cohorts, each with the capability of maintaining their transit craft. In the sleeper ship scenario, a technological application would have been used to put humans in a state of sleep-like near-death, in which the individuals who began the voyage would have been the same to finish it. Both methods of transit have different advantages and risks associated with them.
The generation ship method carries with it the advantage of individuals being able to resolve mechanical and navigational issues with their spacecraft, but also it carries the societal risk of the "in-between" generations taking different outlooks on the voyage itself when compared with the initiating generations. Those "in-betweeners" might come to see themselves as akin to sacrifices, with their lives lived in service to their parents and their children's long-removed grandchildren. The potential for demographic decline with the "in-betweener" generations would also carry significant risk. Additionally, the resources necessary to carry an unknown quantity of generations through interstellar space would have been massive, and as is known of Solsailing technology, the more mass that a ship has, the more thrust (and thus sail-area) is necessary to achieve relativistic speeds and to slow from them.
Due to the immense mechanical, resource, and societal risks of generation ships, the majority of Zemaian migration proponents thus hold that the circumstances of the migration were carried out with so-called sleeper ships. In this scenario, the primary sources of risk are purely computational and mechanical. Navigational errors would have to be corrected with artificially intelligent ships systems, and as a result, the risk of mechanical failure carries greater impact on the overall possibility of such a voyage. Even if the navigation through interstellar space was successful, the baseline conditions of the ships themselves and the possibility of mechanical failure would bare great impact on the conditions of the sleepers upon their arrival in the Aidus system. Furthermore, the sleeper scenario involves an additional level of environmental risk, in which the pre-programmed artificially intelligent navigation systems could possibly encounter some phenomena of a completely unexpected nature.
Arrival conditions
One contention of the Zemaian migration theory is the degree to which Orbalia and the other Aidusal planets suited human habitation upon their immediate arrival in the system. If humanity originated on a different planet, then it would be likely that the human physiology would be unsuited to life on a world with alien characteristics. The world would necessarily have air that was breathable to human lungs, food and fluid compatible with the human metabolic system, and climate conditions suitable to a non-technological human ancestor species. If humanity was not native to Orbalia, then there would be several possible explanations for its colonization upon the arrival of the human species on the planet.
When the Zemaian migration is considered, it is likely that a candidate for colonization would have been selected based on its suitability to human habitation. According to every historical source, and even aside from the relationship to the Zemaian migration, Orbalia is considered the home planet of humanity within the Aidus system. Even during the Belvisajine Inquisition this fact could not be concealed; the foundation of the Divinity's capital on the planet and the migration off-world of the Podchin peoples serve as reinforcing historical markers of this. Hence, if one holds the Zemaian migration to be true, and further considers Orbalia as the selected colonization point of the Zemaian immigrants to Aidus, then it would hold that Orbalia was selected as the colonization candidate for its similarities to Zemais.
If one considers the Drevnian Empire on a technological par with the Zemaian immigrants, then it is possible to speculate on the level of accuracy with which the Zemaians would have analyzed Orbalia to be similar to their own home world. Considering the difficulty of changing course in a Solsailing ship in interstellar space (as there are no solar winds to accelerate or decelerate with), then it is likely that the destination of the vessel was selected prior to its departure from the origin system. Hence, with the level of technological sophistication of the Drevnian Empire, it must have then been possible to determine enough information about distant exoplanets to deem them suitable to human habitation. There would have also likely been a margin of error given the nature of the time difference between two star systems; hence, a non-variable star (such as Aidus) would have been an ideal candidate for settlement, as astronomical conditions would remain largely the same by the time of humanity's arrival.
The degree to which the Zemaians would have been capable of measuring atmospheric and environmental conditions on their candidate planets is unknown. Contemporary technology allows for a degree of precision in the measurement of exoplanetary atmospheric conditions that was likely inaccessible to the Zemaians. Should the planetary conditions have been deemed suitable on Zemais, and yet unsuitable upon closer evaluation, there were likely several courses of action that could be taken upon arrival at a destination system. Either the planet was similar enough that only slight modifications to conditions would make it habitable to human beings (as gene editing technology was only developed in the Second Age) or the ship that brought humans to the destination was capable of finding another, more suitable planet. Whether or not human beings themselves would make this determination is unknown; it could have been an artificial intelligence that judged the viability of colonization on a candidate planet upon arrival.
The lack of certainty that the Zemaian migrants would have faced with regards to planetary suitability would have added immensely to the risk of the voyage. Orbalia could have been many things to the arriving immigrants: a perfect match, a near-perfect canvas, or a final substitute for a myriad of unsuitable others before it. Given the discrepancy between the technology needed to travel in interstellar space at relativistic speeds and the technology needed to overhaul atmospheric conditions on a planet, it was likely that Orbalia was deemed the most suitable alternative for human habitation to Zemais itself. Alternatively, it is also possible that Orbalia and Aidus as a whole was but one of many substitutes for Zemais; that instead of one singular migration from Zemais with a singular destination, the migration to Aidus was one of multiple, and that it was deemed sufficiently risky enough to send colonists to a singular world that many were selected for a first trip. Whether or not the multiplicity of destinations involved a secondary voyage from one failed candidate to a successful one can only be deduced as untrue from the lack of secondary arrivals to the Aidus system following the migration some 120,000 uecs before present.
Evidence
Archaeological
The archaeological site of Meddon Spulcre in central Bunt Land, Orbalia, is the largest pre-Belvisajine settlement known to contemporary researchers. The structures there indicate the presence of advanced metallurgic fabrication, nuclear fission, centralized sewerage, and even aerospatial landing facilities. As of the 13th millennium of the Fourth Age, no older archaeological sites have been discovered on any of the planets of the Aidus system. The distinct lack of archaeological evidence of a pre-nuclear theory human civilization has often been pointed to as a hallmark of the Zemaian migration. Proponents of the migration theory argue that if humanity as a species had evolved on Orbalia, then there would be both archaeological and paleontological pointing to the history of humanity's civilization and genetic ancestors.
Archaeological efforts to prove the development of humanity on Orbalia have long yielded little success, but at the same time, little positive evidence towards the truth of the Zemaian migration has been discovered either. Beyond the Belvisajine Inqusition, the Two Uec War devastated the surface of Orbalia, with a distinct focus on the narrow meridional band containing the bulk of the planet's inhabitants. Critics of the Zemaian migration theory often point out that the destruction levied on the planet during the Two Uec War was so intense that little evidence remains of even the post-First Age civilizations which had flourished there. Even Aetarlux, once the largest city in all of human civilization, was almost completely erased during the bombardment by the Velesan Yedinstate.
Historical
Commentaries from the Forgotten Age are extremely rare. Many of the most once-renowned documents have been proven to be forgeries. One of the most consequential of pre-Belvisajine source materials are the Meddon Spulcre files, a series of medical documents discovered at the Meddon Spulcre archaeological site and preserved in good condition. While the files consist mostly of case reports of patients cared for at an ancient clinic, they provide insight into a number of details of the inhabitants of the earliest dated ruins known to contemporary historians. The files are written in Anglatin, a precursor to the modern Volsh language. Each of the files lists the name of a patient, general personal details such as eye color, weight, height, but most notably, information on the medical procedures undertaken by clinic doctors. References to advanced procedures and medical instruments indicate further that the society at Meddon Spulcre was highly sophisticated, providing a crucial historical link between the widespread usage of the Anglatin language and the point at which certain other technologies saw prevalence in that time.
Much of the primary historical sources of the Belvisajine Inquisition have long been considered poorly demonstrative in their representations of the pre-Divinity Drevnian civilization. What information that can be derived from these sources is often arrived at through interpretation, meaning that there lingers alongside such work the possibility of misinterpretation gross or acute. The Ueclicals of Belvisaj I extensively document the life of the Drevnian Divine Leader Belvisaj I, providing some insight as to the nature of the Belvisajine Inqusition and its impact on the historical record. References to the destruction of "documents describing the most vile of heresies" are found throughout much of the earlier Ueclicals. According to orthodox interpretations of Drevnianism, humanity came to be through the direct influence of an advanced alien spies, or rather, that humanity itself is descended from such a species as its physical manifestation. The "heresies" as attested by Belvisaj I are believed to have at least in part been documentation containing the nature of humanity's earliest development in the Aidus system. While the precise subject of these "heresies" are merely conjecture, the Belvisajine Inquisition was only thoroughly interested in erasing historical as opposed to scientific knowledge. Indeed, much of the basis of human civilization's contemporary scientific achievements and understandings rest on information believed to date from the Forgotten Age. Hence, while much is known of the extremely long span of evolution of non-human animal species, the distinct lack of information on the development of human beings is believed to be an intentional consequence of the Inqusition.
The only other primary sources dating before the Belvisajine Inqusition come from Velesa. The Trenshaya Codices are a series of electronically preserved logs of the Podchinic evacuation of Orbalia during the Drevnian Wars. While these logs are sparse in terms of contextual details, many of them make frequent references to the "young" age of human civilization in the Aidus system and the severity of the consequences that the Drevnian Divinity would exact on the human "project." A number of popular interpretations of these documents exist, including the most well known, which is that the "young" age of human civilization is a direct reference to the mere three generations of distance between the Zemaian immigrants and the Podchinic evacuees. However, no physical copies of the codices are known to exist, a fact often attributed to the successive Velesan civil wars of the middle to late Second Age, which most notably resulted in a twice-rendered destruction of Trenshaya, the oldest city on Velesa. Hence, critics of the Zemaian migration theory often dispense the codices as forgeries, although this has never been conclusively demonstrated either.
Physiological
Some of the most widely discussed evidence for the Zemaian migration comes from the physiological condition of human beings, most notably, the circadian rhythm. The human sleep pattern is biologically constricted to a period of around 24 hours, but at the same time, this rhythm is influenced heavily by the zeitgeber of light produced from the star Aidus on the surface of Orbalia. A number of lifeforms on Orbalia diverge significantly with regards to their sleeping patterns; while a handful of lifeforms, including humans, are biologically conditioned to a 24.25 hour sleeping-waking cycle, a majority of Orbalian lifeforms are conditioned to a sleeping-waking cycle of 73.45 hours, which is roughly half of one uec. This huge biological discrepancy has long been the source of investigation and classification: 24.25 hour circadian lifeforms are categorically and taxonomically distinct from 73.45 hour lifeforms. Even in the investigation of cellular structure and genetics, the 24.25 hour cycle lifeforms diverge significantly from the 73.45 hour ones.
The most intriguing differentiation between the 24.25 hour and 73.45 hour lifeforms is the nature of their existence. Whereas all 24.25 hour lifeforms are animals, all 73.45 hour lifeforms are plants, fungi, and bacteria. The striking difference between the circadian rhythms of animals and plants has a number of explanations which are considered to be "value neutral" in their assessment of the origin of these beings: whereas animals are mobile and capable of finding shelter in which to shield themselves from light during sleeping periods, plants are immobile and thus incapable of preventing self-oversaturation with light. The density of animal and plant life is then significantly impacted by the cyclical variations of light due to Orbalia's axial tilt: the magnetic polar regions of the planet are home to a much higher density of non-migratory animals and hardier plants, whereas the animal and plant life in the equatorial regions of the planets are much the opposite.
The exact fitness impact that the differences in circadian rhythm between animal and plant life on Orbalia are difficult to compare. Over time, adaptation to the circumstances of the planet maximized the fitness of its lifeforms, regardless of wherever the lifeforms are to have originated. What is perhaps the most telltale sign of significant change between animals and plant life is the rapid oxygenation event that occurred on Orbalia beginning roughly 120,000 uecs before the present, a timeframe which Zemaian migration theorists hold as the date of the arrival of humanity in the Aidus system. During this period, oxygen concentrations at sea level on Orbalia rapidly rose from around 17% to 21%, evidence which has been confirmed through repeated ice core samples of the Antisolar Glacier, which further demonstrate that before 120,000 CBP, oxygen levels were only rising at an extremely slow pace. The precise impact that this rapid oxygenation event is believed to have had on animal and plant life is difficult to ascertain: Zemaian migration theorists hold it up as evidence of humanity's intervention on the natural condition of the Orbalian atmosphere, while Orbalian homeworld theorists believe the event was seminal in the rapid enlargement of the human brain, and thus, the root cause of humanity's supposed saltation from primitive civilization to a more advanced instance.
Orbalian homeworld
The other major scientifically plausible theory of human origin, the Orbalian homeworld theory posits that humans are a native species to the planet Orbalia. Throughout the end of the First Age and the beginning of the Second Age, the Orbalian homeworld theory was the most prevalent academic and popular belief about the origin of humankind. Over the course of the late Second and early Third Ages, however, the general shift towards the Zemaian migration theory occurred, beginning primarily with historians and later expanding to a number of archaeologists, paleontologists, and, lastly, the general population. Among these groups, the Orbalian homeworld theory is now viewed critically as an academic "reaction" to the extreme ideological scrutiny of the Drevnian Divinity and the chokehold that Drevianism had on academic freedom and integrity. Generally, the Orbalian homeworld theory is believed to lack the rigorous deductive and evidential qualities possessed by its more prevalent, rival origin theory. Nonetheless, the Orbalian homeworld theory remains endorsed and supported by a significant minority of academics.
Rarity of life
A critical component of the Orbalian homeworld theory is the apparent rarity of particular exological conditions of the Aidus system, and more precisely, of the planet Orbalia and its relationship with its parent star. Orbalia rests squarely within the frost line of the Aidus system, permitting liquid water to exist on its surface. While liquid water exists on the surface of Pechlus, Velesa, and Chaius as well, only on Orbalia does this liquid water interact with planetary-scale continental landmasses. Given the existence of four out of seven planets in the Aidus system containing liquid water, and then a further one out of seven containing continental landmasses, it can be deduced that there is some level of normalcy to this arrangement in the galaxy, given its billions of individual star systems. What hones the uniqueness of the Aidusal-Orbalian relationship, however, is the non-variable nature of the star Aidus; its low level of hydrogen-to-helium fusion, low luminosity, and its extremely strong magnetic field. Both Aidus and Orbalia share the quality of strong magnetic fields in common, and the non-variance of the star further points to the extreme suitability of Orbalia towards the development of a stable hydrosphere on the planet's surface.
Only a handful of Orbalia-sized planets within the frost line of their parent stars have been identified within the 100 parsec neighbourhood of the Aidus system. Furthermore, of this handful, even fewer orbit non-variable stars at distances which reflect similar stellar fluxes respective to the luminosity of their parent stars. Hence, while it is indeed conceivable that Orbalia-like habitable planets exist in other star systems, they are demonstrably relatively few in number. Aside from their exological rarity, what is more significant is the atmospheric and magnetic conditions of these planets, which are qualities difficult to measure accurately through the strong magnetic distortion of the Aidopause at the perimeter of the Aidus system. Without access to more precise measurements, it is very likely, then, that the number of Orbalia-like planets with habitable atmospheric and magnetic field conditions in the whole of the Milky Way is extremely small.
Even more prescient on the rarity of the unique circumstances of Orbalia is the likelihood of the development of lifeforms at all. Native lifeforms are found on three of the seven planets of the Aidus system, namely, Pechlus, Orbalia, and Velesa. Each of these planets is host to liquid water and a strong magnetic field as well as suitable levels of stellar flux and the non-variance of their parent star. The lifeforms of each planet are known to have developed separately albeit with variant complexity: by far, the most complex organic life is found on Orbalia, followed by Velesa, and lastly, Pechlus. Proper animal and plant life is only found on Orbalia and Velesa, as on Pechlus, life is limited to a microscopic level. Given the development of complex life on two out of three worlds, and then the supposed development of sentient life on one out of three worlds, it becomes apparent that the possibility of the development of life is not improbable on the alien worlds beyond the Aidus system, but that the development of complex animal and plant life, and then furthermore, the development of sentience, is likely a rare phenomenon.
Biosphere cohesion
While there are numerous significant differences between the genetic and cellular structure of lifeforms on Orbalia, they consist of similar organic compounds as one another. This feature of Orbalian lifeforms is critically important for understanding the degree to which they are connected with one another; although the circadian rhythms of animals and plants on Orbalia diverge from one another, their basic trophic relationship remains intrinsically bound together. The 73.45 hour circadian rhythm plants serve as the primary autotrophic energy sources of the 24.25 hour circadian rhythm animals. Continuing down the food chain, other 24.25 hour heterotrophs then predate on the consumers of the primary autotrophs. Hence, while the genetic differences between animals and plants are stark and deep-seeded, the trophic relationship between the two is not hindered by this difference.
Another important aspect of the Orbalian homeworld theory is the explanation of the rapid oxygenation event that occurred roughly 120,000 uecs before the present. In an evolutionary timescale, this event occurred in the extremely recent past, meaning that its impact on life on the Orbalian surface would have been acute, possibly to the point of hindering or even stopping altogether the evolutionary development of any surface-dwelling, air-breathing species. Many Orbalian homeworld proponents point to the rapid oxygenation event as the point at which human beings experienced a period of significant physiological over-efficiency, and thus, the impact was as rapid as the change in atmospheric condition. Most crucially, this argument rests on the size of the human cranium; humans possess the largest overall brain mass and surface area of any animal in the Aidus system. Yet, a common criticism of this explanation is that if humans would be adaptable and susceptible to such a rapid change, then it would more likely than not similarly effect other animals with whom humans dwell on the Orbalian landmass.
Additionally, while there exists no paleontological record of an earlier human species on Orbalia, the paleontological record of other species is similarly non-existent. Orbalia, much like Velesa, contains no fossil record. The similarity there between Orbalia, a world with prominent landmasses, and Velesa, a world whose lithosphere is entirely covered in liquid water, is a prevalent feature of the Orbalian homeworld argument. Critics of this viewpoint, however, then question why the word "fossil" even exists within the lexicon of any Aidusian language, and what precisely its meaning entails if not that of something related to being "dug up," as it is etymologically classified by the Liber Institute for Anglatin Study. The most common rebuttal of this argument comes from the impact of the Two Uec War on the meridional band of Orbalia: the bombardment was so severe that any near-recent paleontological record would have been erased by it. However, even in the inland Subsolar Desert, when the theory of continental drift is considered, it would be highly unlikely that the entirety of the Orbalian fossil record could have been wiped out by the bombardment of even the most distant terrestrial regions.
Historicity
There are a number of criticisms levied against the Orbalian homeworld theory that go beyond the mere instantiations of points in its favor and trace the belief along historical lines. Principally, historians who support the Zemaian migration theory find that the Orbalian homeworld viewpoint was likely a reaction against the hardline theological stance of the Drevnian Divinity towards the origin of humanity during its zenith in the First Age. While the Belvisajine Inquisiton deliberately and systematically destroyed anything it condemned as heretical, going so far as to root out specific beliefs and ideas in the public conscience, it did not aggressively seek to destroy much of the scientific knowledge that predated the ideological transition. Instead, much of what was considered generally accepted science during the Forgotten Age was co-opted by the Drevnian Divinity during the First Age; that which aligned perfectly was most vehemently endorsed, while that which resulted in inconvenient questions was quietly ignored or purged. General Drevnian knowledge related to the fields of archaeology, biology, and paleontology were thus preserved, while specific knowledge and documents related to the history of humanity were purged.
During the Sundering War, a sense of anti-Drevnianic sentiment pervaded the Volsh and Podchin societies of the Aidus system. Scientists trained during the end of the First Age thus became highly skeptical of the dogmatic histories featured in the Drevnianic corollaries and scriptures. Having lost access to much of the information which was once widely available during the Forgotten Age in relation to the history of the human species, the preserved principles of the scientific method were then applied to the realms of knowledge which had been eschewed of any Drevnianic dogma. Hence, the most popular and emergent of theories explaining the origin of humanity in the Aidus system fell in line with the principle of parsimony: that the simplest explanation of humanity's origin was likely the most true. When combined with knowledge of the theory of evolution and the examples of biological lifeforms at hand, the notion of humanity evolving on Orbalia became relatively popular.
The development of this line of reasoning, say critics of the Orbalian homeworld theory, is both understandable in its context and yet also flawed. Instead of actively investigating the scientific explanation for the presence of humanity in the Aidus system, it became a matter of simply moving in the opposite direction of a viewpoint which was considered to be itself anti-scientific. The contemporary Imperial historian Tosha Gord reflects that "the idea that humanity possessed no divine heritage... became just as dogmatic for the Anti-Divinists as the opposite was true for the Divinists themselves."
Seeding
A notable tertiary viewpoint on the origin of humanity in the Aidus system is the Seeding theory, sometimes referred to as the Xeno-Creator theory. This particular theory has a long history in the Aidus system as a variation of it was once promoted by the Drevnian Divinity as the truth of humanity's origin in the system. For this reason, the Seeding theory was it is known in the contemporary period is sometimes held as a distinct viewpoint to the Xeno-Creator theory. This distinction is a mere issue of nomenclature: the precepts of the Seeding theory are often regarded as more scientifically grounded than the Xeno-Creator theory. The Xeno-Creatory theory is based upon the Drevnianic scriptures derived from the work of the Divine Leader Belvisaj I, and as a result of this, proponents of the Seeding theory often describe the association of their own beliefs with the Xeno-Creator theory to be intentional slander of an otherwise scientifically plausible viewpoint.
Seeding vs. Xeno-Creation
The precise differentiation between the Seeding and Xeno-Creator theories is made primarily by the proponents who favour the nomenclature of the "Seeding." These supporters argue that the description of the Seeding itself as intrinsically tied to the idea that humanity was designed by an alien species is an unnecessary and likely incorrect extrapolation of an otherwise scientifically plausible theory. Seeding proponents describe the human origin in the Aidus system as the artificial implantation of the human species on the planet Orbalia and then humanity's development there as otherwise through the natural course of civilizational development. In essence, the primary distinction between the Seeding and Xeno-Creator theories is the degree to which the artificial implantation of humanity was followed up by a guided construction of human civilization. While Seeding proponents do not wholly omit the possibility of such a guiding, at the same time, its endorsement is not considered to be grounded in an evidence-based approach towards the origin debate.
Likewise, those who support the Xeno-Creator theory hold that an alien civilization guided the development of the human species. The degree to which humanity has strayed away from or moved towards the ideal form of society as laid out by this alien civilization is a matter of religious identification. Orthodox Drevnianic faith holds that humanity fell out of favour with its creator/seeder alien civilization, and that through the will of the Divine Leader and the purges of the Inquisition, an order favourable to the alien creators could be implemented, so long as the whole of humanity fell under the whims of such an order and was unified in its faithfulness towards it. Orthodox Drevnianic religion later collapsed during the Sundering War, when the divide between the Littraelists and Paixists solidified into new instantiations of the Drevnianic religion. Later developments with Septoilanism and Estrelism redefined the relationship of contemporary humanity with its alien creators. Both extant branches of the Drevnianic faith hold onto the Xeno-Creator theory in its more hopeful, Paixist interpretation: that once humanity is unified under a common commitment towards a return to its primordial ideal, that the alien civilization who breathed existence to humanity would reunite with it once again.
As a result of the heavy religious influence on the Xeno-Creator theory, proponents of a scientifically grounded Seeding theory often insist upon a distinction between the two. However, too significant of a distinction often leads to accusations that the Seeding theory is in essence just a variation of the Zemaian migration theory, which Seeding theorists often reject as too bound up in conjecture as well. The primary difference between the Zemaian migration and Seeding theories is that the Seeding theory claims to posit a less "risky" transit through interstellar space. Whereas the Zemaian migration theory holds that grown, adult human beings were transported through space in large numbers, the Seeding theory instead claims that the majority of those transported through interstellar space were merely the pre-reproductive precursors of human beings. Hence, whereas the Zemaian migration posits a continuity of personhood and identity from the Zemais system to the Aidus system, the Seeding theory posits instead the introduction of an entirely embryonic humanity.
Circumstances
According to proponents of the Seeding theory, the factors necessary to motivate the action depend on the precise manner by which it was carried out. The most critical question to the manner of the Seeding the nature of its administration upon arrival in the Aidus system. It is likely not the case that there was no intelligent manager of the operation upon reaching the destination planet, as the risks associated with the lack of oversight of its administration would essentially outweight the benefits of performing the Seeding at all. Indeed, the motivation behind the Seeding plays a critical role as well in determining how exactly the Seeding itself was carried out. It would appear likely then, Seeding proponents argue, that there was some sort of intelligent, decision-making entity present at the administration of the Seeding, one capable of making judgements based on the risks associated with the unique circumstances in which the Seeding vessel would find itself.
The presence of an intelligent decision maker for the Seeding to be successful opens the subject to a myriad of possible conjectures. To Xeno-Creationists, the intelligent decision maker would be the alien civilization that brought humanity into existence. To proponents of the Seeding theory, there are a number of less improbably options that are typically argued for. The most popular candidate for an intelligent decision maker is an artificial intelligence that monitors the ship's navigation through interstellar space and the raising of the first newborns upon landing on Orbalia. Such an artificial intelligence would not necessarily need be mobile itself; it is often held that the vessel used to transit interstellar space would contain the "seedlings" in landing-capable craft. Upon landing on the planet's surface, the reproductive element of the Seeding would be triggered and the young humans would spend their formative years in the landing craft, being educated and closely monitored by the artificial intelligence.
The less popular theory among proponents of the Seeding is that an individual human was placed in charge of the Seeding of the world. Much as with the Zemaian migration theory, this individual was placed in the care of an artificial intelligence during the voyage through interstellar space, and upon arrival on Orbalia, they became responsible for the raising of the first generation of Orbalian-born humans. While this theory of human origin follows close to the Zemaian migration theory, the critical difference between the two is in the underlying risk of the process of sending hundreds of thousands of adult-aged human beings across interstellar space as opposed to the mere "ingredients" for human beings which are then "assembled" in situ. In this manner, no "living" beings are put at risk through the Seeding process, whereas with the Zemaian migration, individual human beings are risking death in interstellar space or even for a number of other reasons in order to continue living in a new location.
The most challenging aspect of the Seeding theory, then, is in the motivation to undertake such a project when compared to a migration of living human adults. Where as with adults the motivation to migrate across the stars is to continue the process of one's life on a new, unspoiled world, the motivation to send pre-embryonic human-making materials to a new star system would indicate a much different desire on the part of the mission-initiator. As opposed to the fleeing of circumstances deemed unsuitable to continue living on one world, the Seeding theory instead represents the ability for a human civilization to potentially replicate itself in a different star system. If the individual is no longer the object of preservation, then it might be argued that instead it is humanity more generally whose preservation is the object. Hence, proponents of the Seeding theory often refute the idea that Orbalia-like worlds are rare, and that instead there have likely been hundreds of human colonization efforts through the Seeding method, so as to sustain the human species indefinitely in its broadening of protection from the risk of being bound to a singular solar system.
Historicity
As with the other theories of humanity's origin, the Seeding theory suffers from a lack of concrete evidence towards its truthfulness. The largest body of evidence towards the historicity of the Seeding is often held up as the Drevnianic scriptures of the Belvisajine Inquisition, in particular, the Ueclicals of Belvisaj I. Throughout the Ueclicals, the Divine Leader make constant reference to the nature of humanity in the Aidus system. While an extrastellar species is regarded as the progenitors of humanity, it has been argued by many secular Seeding proponents that there is some amount of truth within the Divine Leader's more religious framing of humanity's origin. Many Seeding proponents would dismiss the idea that the Seeding itself was initiated by any other race than the human species itself; that "They, the Holiest" to which the Divine Leader makes constant reference is in reality the human ancestors of the Aidusian human population merely located in a different star system. In the purging of "heresies," it is likely then that the Divine Leader is referring to evidence that it was a human-led initiative to seed the Aidus system with life. Furthermore, this interpretation of the exact constitution of heresies for the Drevnian Divinity is not wholly inadmissible as to the "project" referred to in the Trenshaya codices and that the "young" civilization of humanity in the Aidus system could be more literally interpreted as the raising of a new generation by the intelligent decision-maker.
It is frequently pointed out by Seeding proponents that anything archaeologically significant to the Zemaian migration theory is also just as likely evidence for the Seeding theory as well. So long as no archaeological sites are found pre-dating those at Meddon Spulcre or Tristan with evidence in favour of the Orbalian homeworld theory, there remains the equally the possibility of the Seeding as much as the Zemaian migration. The largest difficulties that could be conceived in criticism of the Seeding theory, then, is the difficulty which an artificial intelligence would face in raising an entire generation of human beings with no support from that species. It would seem likely that if an artificial intelligence attempted to raise a child, that some sort of developmental issue would then manifest with that child, as the importance of physical contact has been demonstrated in the successful upbringing of children. In such a case, it would not be inconceivable to rebut that the intelligent decision maker would be far more complicated a thing to create than a robotic construct it could inhabit to truly fulfil the role of parentage. Likewise, many Seeding theorists will often point to the extreme violence of the Drevnian War as a potential example of the societal instability that a human civilization founded entirely by artificially intelligent robots would bring about.
The destruction of artificial intelligence is a well-documented aspect of the Belvisajine Inquisition. Belvisaj I wrote that their pervasive intrusion in human society would be its undoing. Seeding theory proponents often cite the frequent references of artificial intelligence as "abominable" in the Ueclicals as pointing towards the role they could have played in the upbringing of children in the Drevnian Empire. It has been well corroborated by historians that the excessive use of artificial intelligence and its embodiment in automotive robotic constructs was a key trigger of the Belvisajine Inquisition. Furthermore, Drevnianic religion has long been opposed to the reintroduction of artificial intelligence in any significant capacity in human civilization throughout the Ages of recorded history. Hence, Seeding theory proponents surmise that the Belvisajine Inquisition itself was a reaction against the nature of the Seeding as carried out by an artificial intelligence and that the writings of Belvisaj I reflect this inference.