Update Thread 43: ... I got nothin'

[Mamorien]

Sunday, Sunday, SUNDAY!

The "Species Problem" is the general term in the biological sciences for the difficulty in defining what a "species" is, with literally dozens of recognized methods and criteria for the definition of a "species."  And in the context of this text, one of the more well-known examples—which has literally been known to start fist-fights among biologists of the author's acquaintance—is the question: are dragons one species, or many? (Note that first priming the biologists with strong drink or a lectern podium aids in achieving the desired results). 
The issue with defining dragons as a species is that dragons are, both in their genetics and phenotypes, a "terrible mess," to quote Frelsifrædi, Haddock, Levi and Lewis in their seminal paper "Genetic Variety Of Worldwide Draconic Populations: Diversity And Bottlenecks" [Journal Of Genetic Studies, Summer, AD 1781].  Dragon genetics and populations resemble a river delta, with numerous braided tributaries and links of gene flow between different populations.  In general, the archaeological record tells us that ancestral dragon population originated on Syndriland and migrated to the Javanese archipelago between 18 and 15 million years ago, where the numerous volcanoes and rich fishing waters of those island arcs helped define the dragon species' specializations as flying, fire-breathing semi-obligate piscivorous social animals who use geothermal hot spots as breeding sites. 
However, genetic analysis shows that, even during those early days, dragons were already specializing into different forms that were still part of a larger population capable of interbreeding and gene flow.  After leaving the Javanese islands and spreading out over the rest of the world, population isolation and mutation resulted in the creation of more breeds of dragon—but, like dogs, they are still generally capable of interbreeding with other members of their species.  Generally.  And here lies the headache of defining dragons as a singular species or as several distinct-but-closely-related species.  Because where does one draw the lines for the distinctions?
To illustrate this, consider that there are a number of general parent categories of dragon, with the precise count depending on the schema used.  The ancient Norse used a six-category system based on the dragon's general affinity (Stoker, Sharp, Boulder, Strike, Tidal and Mystery), a system which has survived to the present in various technical vestiges and common parlance.  Other systems have been devised in the years since those days, many of them more accurate but also more technical, and we will be addressing those later in this text.  But to use the familiar terms from the archaic system, generally speaking most Stoker-class dragons of the same size are capable of interbreeding and producing viable young.  The same goes for most Boulder-class dragons and so forth.  However, a Boulder-class and a Stoker-class might not be able to interbreed as successfully, although such crosses are known. 
To quote Dr Susana Fyodorna, the leading dragon geneticist at the University of Kyiv, "It looks as if the dragon genome takes the feature sets from the parents, smashes them together, and sees if it explodes or not.  Six limbs?  Four limbs?  Heptane or kerosene?  Spawn it and see if the build works!"  (Further note: Dr Fyodorna has a very potent left fist).  And her statement is essentially accurate; if the genetic code proves viable then a dragon is hatched, possibly one with unique features.  If the genes aren't viable, then the fetus might miscarry, with the most extreme examples resulting in the egg exploding in a manner similar to embryos with developmental defects.
In essence, the more similar two dragons are, the more likely they will be able to mate and produce viable offspring, but, to the frustration of biologists—and the amusement of their onlookers—this does not preclude successful matings and breeding between dissimilar dragons.  And while there are populations which are so dissimilar that there are no records of successful crosses, a line still cannot be drawn around one population separating it from another as "one species," not when there is still gene flow.  Yes, a Terrible Terror and a Bewilderbeast are certainly not capable of mating together, much less producing viable offspring… but the Terror can mate with breeds adjacent to it in size, as can the Bewilderbeast, and, via a dozen or more intermediary breeds, there can be gene flow between them—and drive the recording biologists to drink and pugilism. 
The reigning theory at present is that most dragon breeds are simply specific sub-populations of the greater dragon species which have achieved self-sustaining population numbers, and as a result can find similar mates without too high a degree of consanguinity.  Some of these populations have almost completely diverged from the greater species, such as the multi-headed breeds, where others, especially among the Strike-class dragons, have small populations and require regular interbreeding with other dragon breeds in order to avoid dangerous levels of inbreeding.  Strike-class in particular have high rates of egg miscarriages due to this factor—the biological tolerances on their plasma-generating organ systems are simply so stringent that developmental disorders are nearly always fatal, but their numbers are often so small that they must mate with dragons from different breeds to avoid inbreeding, meaning that the parental differentials often have terminal results for the embryos.

This week's A Thing of Vikings starts on Berk, where Tuffnut has done something I did not, for one, see coming any more than he did. Over on Eigg, Hiccup (and his bud) help Gobber finish moving into the Joms smithy and set about christening it properly, whereupon the Hero gets a chance to explain the need for bread-making Vikings and small-home-repair Vikings. Back on Berk, Fishlegs settles into stewarding and contemplation of his problems, unburdening himself to the one friend who can never tell another human. In Almatu, on the great steppes, Drago earns this chapter its warnings for explicit depiction of combat, explicit blood, and explicit death, via yet another hilariously doomed ambush. And we close on Berk, where Esther is helping Wulfhild when Fish arrives with startling news from the Broodery...

https://archiveofourown.org/works/104089...s/58382569