There isn’t much science in book 1 — at least, not visibly.  As a former student of the hard sciences and a current interested dabbler, however, I can’t help but create scientific underpinnings for many of my magical and spiritual happenings.  Some people don’t like that, or at least so I’ve been told; they want fantasy to be completely its own imaginary beast, without the need for anchors of investigation or testing.  Since I’m trying to build a large world, though — and more than that, a world that changes and progresses through the ages — I can’t bend to that kind of philosophy.  Beside that, I don’t want to.

I want to know how you get from wolf to man.

The lay explanation is fairly basic.  Skinchangers are each attached to their parent beast-spirit, whether it be the Wolf, the Crow or the Hare, each of which has a corresponding beast form.  The beast-spirits also have a ‘Mask’ form: a humanoid version, which they once used to try to infiltrate the wraith ranks.  Because the beast-spirits are not bound to any physiology but all were split off of a primordial shapeshifting Great Spirit, they are able to change between these two forms — and through various intermediate ones — at will.  Because of their continued connection to their mortal offspring, they can also extend that physical fluidity to the skinchangers, though it’s more painful and takes more time for the skinchangers than it does for spirits.

The entire shapeshifting ability is predicated upon a connection to the patron spirit.  So how does science come in?

Shapeshifting itself is not a purely fantastical conceit.  I don’t mean this in a ‘werewolves’ manner, but in biological adaptation to new conditions and niche environments — i.e. evolution — and in shorter-term transformative behaviors such as camouflage and active mimicry.  In nature, there are hordes of creatures that have adapted to look like predators when they are really prey, to look bigger or smaller depending on the need, or to just fake being whatever they feel like.  They can roughly adjust their size and shape and sometimes color via voluntary manipulation of body parts, without losing the biological basis of what they are.

I see Halion skinchangers as more fluid and more large-scale versions of those natural creatures.  The world of Halci is as transformationally adapted as it is evolutionarily — by which I mean that evolution takes place, but quicker and more easily, to the point that it can be consciously directed from generation to generation by a patron spirit.

Skinchangers aren’t actual animals which turn into actual humans.  They are metamorphic entities that have been given two templates by the energy that connects them, and can move smoothly between these templates.  Like the mimic octopus in the link above, they are always the same basic creature, but sometimes it shifts its ears down and pulls in its fur and claws and calls itself a man, and at other times it adjusts its joints, extends its jaw and shows its tail and calls itself a wolf.

(And by the way, some traits are more difficult to shift.  Skinchangers with tails don’t lose them when they become human; it would take too much time, pain and calories to regrow that part of the template.  They’re not primordial balls of undifferentiated silly-putty that can be pushed into any pattern.  A hand can’t become a mouth, or an ear turn into an eye, because the templates overlap as much as possible for the purpose of conserving energy and agony.  Most skinchangers in human form are still visibly inhuman: eyes too large or too small, dentition wrong, too hairy or too hairless, scary nails, badly-hidden tails, weird gait, animal smell, pelt-markings.  The Mask isn’t perfect, but it works well enough at a distance.)

This brings up a question of what skinchangers’ bodies are made of.  Do they have normal bones?  It doesn’t seem likely, considering the lengthening and shortening and bending necessary to take on a new form.  So what, then?  Flexible cartilage?  Dimensional manipulation?  What about stretching skin and appearing/disappearing hair?  I’m not perfectly certain about this.  I have a theory involving the spirit realm: since skinchanging is predicated on a spirit connection, it seems reasonable that some things such as fur can be ‘pushed’ into the spirit realm and ‘pulled’ back when needed, rather than biologically shed and re-manufactured.  Likewise, since switching between templates connects the skinchanger directly to the essence of their patron, which has been stated to heal all wounds (as the skinchanger becomes synchronized with their unwounded patron), it is possible that all the nasty splintering and stretching that you see in werewolf movies does happen — only ultra-fast, and is so smoothly mended that it’s barely even noticed.

Some skinchangers don’t even try that hard.  There are several types — notably the crows and the scorpions — who change the bare minimum of features required to speak human languages and to have an identifiable ‘human’ face, and don’t much bother with the rest.

And some skinchangers don’t try at all.  Ogres and goblins are both technically skinchanging races, but their patron spirits chose to adapt to a single semi-human template rather than clinging to two.  While ogres and goblins have a sort of spirit-memory of their original beast-forms and can — with great effort — change into a throwback version of that primal form, they can’t go further toward the human Mask; the spirit does not offer that option.

What we come to now is what the human Mask accidentally triggered among the skinchanger races: interbreeding.

Skinchanger Type A + Skinchanger Type B = human baby.

Why?

Skinchangers and their spirits are all descended from the original primal shapechanging race and its spirit, yes.  But when the Great Spirit divided into the Ravager and the Guardian — the predator and the prey — a schism was created not just in the spiritual side of the race but in the genetics as well.  All creatures attached to the Ravager suddenly had what could be called an R gene, while those with the Guardian had a G.  When the Ravager and the Guardian thereafter split off portions of themselves into their own ‘child’ spirits — which would become the beast-spirit patrons — they further split the genetic codes of their mortal offspring apart until each skinchanger group was its own race, bound to its own niche.  Each was defined by its beast-patron’s template and no other, and while there were superficial variations between members of each race — in features, in coloration and personality — they were all essentially outgrowths of one genetic lineage.

The only common thread between all mortal skinchangers is the skinchanger gene.

As the part of their genetic code that allows shapeshifting, the skinchanger gene can be considered their last link to the primordial Great Spirit.  It also connects them to their patron beast-spirit; without an active skinchanger gene, one can pray to a beast-spirit and be answered, but never be fully connected.  It is the spirit’s anchor to the physical body and the physical realm.

It also makes it possible for two skinchangers of different races to produce children.  That lingering connection to the original all-encompassing spirit can override and mesh the otherwise-incompatible genetics just once: in the womb.

Children of such unions come out as humans no matter the parents’ preferred forms, because the human Mask — the biological template for a bipedal front-facing humanoid body structure — was adopted by almost all of the beast-spirits, and thus requires the least amount of adaptation between mother’s and father’s genetics.  However, this adaptation deactivates the skinchanger gene.  No human, even if born to two skinchangers, can shapeshift naturally.

The skinchanger gene has implications beyond humanity, though.  Because it is empowered by its connection to a patron spirit, it can be deactivated by the death of that spirit — destroying an entire race’s capacity to skinchange.  Such has happened many times in Halci’s history, locking former skinchangers into whatever shape they had been in at the moment of the spirit’s death.  The Szari-Nak lost their skinchanging when their patron Szarnos the Bull was slain, and while a few of them were in human form, most had adopted a minotaur-like hybrid form in order to fight, while others were in full cattle-shape.  All became stuck in those forms, unable to breed with any but those stuck in their same form — or, in the case of the ones wearing the human Mask, with humans.

Likewise, the horse-folk who followed Ryntri Lakhigi were irrevocably split into humans and horses when their patron was slain.

With inactive skinchanger genes, these patronless former skinchangers must fall back on their mortal genetics, which recognize their current shape and race and niche and will not permit movement — or breeding — outside of those confines.  While it is possible to reactivate the skinchanger gene in a full-blooded skinchanger, this requires forging a connection to a new patron spirit, whose influence will slowly override the old patron’s beast template.  In the case of followers of Ryntri Lakhigi who prayed to and were connected with Athalarr the Lion, this means that with each skinchange, the former horse-folk slowly became more leonine, until they were indistinguishable from natural lion-folk.

As noted previously, the skinchanger gene in humans is only active at the moment of conception — and then only in a child of two skinchanger parents.  The fertility of that child depends on the genetics of his or her future partner; if one or more of the child’s lineages matches with the partner, they will be fertile, but if none do, they will be incapable of breeding.  Through millennia of interbreeding between populations — and due to the widespread distribution of most types of skinchanger — the human gene pool has become broad enough that there are no longer any particular fertility problems on the main continent; there is a little bit of wolf, or a little bit of deer or fox or hawk or crow, in everyone.

This intermixing makes it difficult — but not impossible — to revert a human to one of their skinchanger ancestries.  The skinchanger gene is still present in all Halion peoples and creatures, even if dormant, and could conceivably be reactivated if a patron appears with a template that fits — or if the subject’s genetics are adjusted to fit an existing patron’s template, and all other interloping templates removed.  Dalurvykhe (also called body-magic, biomancy or medical necromancy) has long been in search of a way to scrub extraneous templates from a human subject without killing them, but so far has had no luck.

Sooooo.  If you got this far, this has been my descent into mashing biology and mysticism together like two handfuls of silly-putty.  Does it work better than just waving my hand and saying ‘the spirits did it’?  I don’t know.  But it gives me a nice logical reason for why the minotaur and the goblin can’t have babies.

(Ew.)