Hybridization and Hybrids Guide
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Wolves, coyotes, jackals, dogs, and anything else listed as a playable Luperci—that is, within the genus Canis—are able to interbreed and produce fertile offspring. These types of hybrids have been proven possible through human experimentation or accidental hybridization in the wild.
Hybrids of species within the family Canidae but not of the genus Canis do not occur in the wild; hybridization experiments have either proven impossible or have not been attempted at all. As such, these hybrids are impossible—maned wolves, African wild dogs, foxes, and other canines may not become Luperci, and they may not hybridize with Canis members.
Hybridization rarely occurs in the wild for a variety of reasons. Some species' ranges are oceans apart, and thus interbreeding is impossible outside of human aid. Other species whose ranges overlap, such as the wolf and the coyote, are generally hostile toward one another and generally will not take mates of the other species. However, in 'Souls we allow a lot more freedom than this—you are pretty much free to hybridize as you please within the Canis genus.
It is generally difficult to predict middle-stage hybridization. First-generation hybrids, sometimes referred to as F1 hybrids, are obviously 50% and 50%—however, “a twice backcrossed individual would be predicted to contain 12.5% of one species' genome (say, species A). However, it may, in fact, still be a 50% hybrid if the chromosomes from species A were lucky in two successive segregations, and meiotic crossovers happened near the telomeres. The chance of this is fairly high ... however, this probability declines markedly with chromosome number and so the actual composition of a hybrid will be increasingly closer to the predicted composition.“1
Hybrid vigor, or heterosis, is the term used to describe hybrids that are stronger than its parents. When a hybrid inherits the good traits of its parents and displays higher adaptability and ability to survive, this is known as hybrid vigor. However, the opposite can also occur in hybridization—“individuals from different populations have lower fitness than progeny from crosses between individuals from the same population.” This is known as outbreeding depression; this can occur especially when hybrids are created from animals that have a differing number of chromosomes.
An example of this would be as the horse and the donkey. While they are capable of producing first-generation hybrids, fertile crosses between these species are exceedingly rare, as their chromosome number differs. Horses have 64 chromosomes and donkeys have 62; the resultant hybrid (a mule or hinny) lies on the scale between at 63 and cannot produce viable gametes and thus cannot reproduce.1 The only Canis species with a different number of chromosomes are the jackal subspecies of Black-Backed Jackal and the Side-Striped Jackals; these canines have 74 chromosomes, while all other members of the Canis genus have 78.
Wolves have hybridized with dogs and coyotes historically; it is suggested that black coloration in wolves is caused solely by interbreeding with dogs, as the mutation for that coloration arose in dogs first.7 "Black wolves with recent dog ancestry tend to retain black pigment longer as they age," and dark fur is also a dominant trait in canines.7 “In many cases the resulting adult wolfdog may be larger than either of its parents.”9 The appearance of wolf-dog hybrids varies incredibly: wolf-dog hybrids may appear to be full-blooded dogs or full-blooded wolves. “Wolfdogs tend to have somewhat smaller heads than pure wolves, with larger, pointier ears which lack the dense fur commonly seen in those of wolves. Fur markings also tend to be very distinctive and not well blended.”9
"'Coydogs,' hybrids of Coyote and domestic dog, especially shepherd mixtures, are larger, usually lack [the] dark vertical line on lower foreleg, and have relatively shorter and thicker snouts."5 Experimentation with coyote-dog hybrids found that after a few generations, there were higher incidences of genetic problems in coydogs bred back with dogs, although this is generally unverified outside of one study. A coydog cross depends on the breed(s) of dogs introduced to the coyote blood, naturally—resulting hybrids typically have a rather feral appearance with clear canis familiaris traits present.
Coywolves are generally much larger than coyotes, with much wider snouts and larger skulls than a purebred coyote. Hybridization with wolves has happened historically, and as coyotes' ranges expanded and wolves' ranges diminished, some hybridization occurred "and helped turn coyotes from mousers of western grasslands to deer hunters of eastern forests."6 The so-called "eastern coyote" is considered to be a distinct hybrid subspecies of wolf and coyote—individuals with as much as 89% wolf heritage have been identified in Pennsylvania.4
Dogs are incredibly varied in appearance, from the large Great Dane to the tiny Chihuahua. There are a large number of dog breeds with various traits and characteristics, far too many to cover in this small section—you can see the page on Dogs for likely candidates for survival. There are some characteristics which would probably disappear relatively quickly—brachycephalic features (upturned, shortened muzzle) would disappear very quickly, as would the short and stubby legs of the Corgi and Welsh Terriers.
Generally, the differences in breeds would gradually disappear, and dog breeds would become landraces adapted to their particular environment rather than breeds specialized for human needs and human aesthetics. One can look at various feral dog types to infer what most of these dogs would look like: Dingoes, pariah dogs, Carolina Dogs, Canaan Dogs, and New Guinea Singing Dogs are all examples of "feral type" dogs. They generally have tawny or yellowish fur, and erect ears. Erect ears are a trait that tends to be dominant across the board in feral canines—upright ears allow for movement and rotation and better sound detection and location.
The Golden Jackal is indicated by genetic research to be more closely related to coyotes, wolves, and dogs than either of the other jackal species.12 Breeding experiments have proven that even Golden Jackals have some degree of difficulty hybridizing with other members of its same genus; fourth-generation hybrids are widely reported to be sterile unless mated back to either parent species rather than another hybrid.
These canines need to be taken into special consideration. Both the side-striped and black-backed jackals have 74 chromosomes, whereas the rest of the Canis genus possesses 78. While this does not necessarily bar these types of canines from hybridizing with wolves, it is likely they would suffer from outbreeding depression as a result of hybridization.13 Breeding experiments between jackals and other members of the Canis genus are typically performed between Golden Jackals rather than side-striped jackals; thus, it is not known exactly how stable these hybrids will be.
Purebred animals of either Dingoes or New Guinea Singing Dogs are typically uniform as far as coloration and patterns go; the Dingo is almost universally tawny yellow in coloration, whereas New Guinea Singing Dogs come in black and tan as well as tawny yellow coloration. Hybridization between dingoes and dogs has been previously recorded; this generally disrupts the uniform colorations and produces individuals with "broken colour-patterns, red with white, black or bluish spots, completely black, brown or bluish, black-and-white and piebald striped patterns"14 Of course, as Dingoes and New Guinea Singing Dogs and Dogs are all very closely related, there is not very much difference with hybridization between these species. Presumably, the wild populations and their dominant characteristics would swallow dog populations in a few years, and hybridization would no longer be an issue.
Wolf and coyote hybridization is suggested to have created or heavily contributed to Red Wolf populations existing around and after 1980. Red wolves are genetically indistinguishable from wolves and coyotes.8 The Eastern Timber Wolf has also been considered to have some coyote heritage. Of course, it is possible that these species were one genetically distinct from wolves, coyotes, and one another; however, as wolves of all types were eradicated from the continental United States, existing populations had no choice but to mate across species lines to ensure the survival of their genes.
It is also possible that such hybridization occurred so long ago, it allowed the hybrids to develop into a distinctive species—however, the last pure specimens of Red Wolves were captured in 1980, and from then until 1987, Red Wolves were extinct in the wild. The release program began in 1987 with four individuals; it is not known how large this program expanded until the demise of humanity in 1988, and so individuals with red wolf heritage are very likely hybrids.
Indian Wolves are controversial in that they are sometimes considered part of the Iranian Wolf populations they always were; however there is evidence that this particular sect of the "Iranian wolf" has not interbred with other canines in nearly 400,000 years, which could make them genetically distinct enough to be considered their own species.11
Himalayan Wolves are also a unique consideration in that they are not known to hybridize with dogs or any other species of the Canis genus. They are controversially listed as both a distinctive species as well as a subspecies of the Tibetian Wolf?. "These wolves share no genetic markers with dogs. This indicates that the Himalayan wolf played no role in the domestication of dogs ... DNA analysis suggests that the Himalayan wolf is distinct from the Tibetan wolf and represents the most ancient wolf lineage ever recorded." 10
- Wikipedia - Hybrid (biology)
- Wikipedia - Heterosis
- Wikipedia - Outbreeding Depression
- Wikipedia - Coyote
- Enature - Coyote
- Adirondack Almanac - Coy-Wolves Evolved ...
- Wikipedia - Black Wolf
- Wikipedia - Red Wolf
- Wikipedia - Wolf-dog Hybrid
- Wikipedia - Himalayan Wolf
- Wikipedia - Indian Wolf
- Wikipedia - Golden Jackal
- Wikipedia - Canid Hybrid
- Wikipedia - Jackal-Dog Hybrid
- Natural History of Mammals in India and Ceylon by Robert A. Sterndale, 1884
- Wikipedia - Interbreeding of dingoes with other domestic dogs