Anthropomorphic animals are, on an essential, genetic level, human; whatever differences they might have from ordinary humans, they remain able to reproduce with ordinary humans, and they all have humans in their family tree. Their appearance is widely agreed to be a consequence of the resurgence of high magic, and humans with high levels of innate magical ability (whether merely potential or actively cultivated) appear to be especially likely to be the parents of anthro children. From a scientific standpoint, all anthros are of the [b]human[/b] species, and in spite of outward appearances are genetically [i]homo sapiens[/i] (with a few very rare exceptions, which are still considered to be near relatives in the [i]homo[/i] genus); the differences of physiology are not sufficient to be regarded as speciation. In spite of this, the type of animal that an anthro resembles is still widely referred to as their "species", though official documents often use the more technical "specioid type".

Some rare anthros are not born of human or anthro parents, instead appearing among populations of non-anthros, being raised mostly feral but still having some innate enculturation that allows adaptation to human culture and behaviors; these are typically the result of either accidents of magical polluton, or deliberate activity by magical entities such as spirits, deities, demons, angels, or fairies. Known as [i]protogenesis[/i], this process is not yet well documented due to its relative rarity and the difficulty in knowing when and where it will occur; as of yet, the moment of creation has not been documented reliably, and those instances that have been witnessed are subject to contention regarding the reliability of witness testimony.

Due to the magical nature of the differences in appearance which anthros have, they are still capable of parenting ordinary human children (or indeed, children of a wholly different specioid type, though this is much less likely). The characteristics of such children will be as if their anthro parent(s) had been born baseline humans, barring any other magical influences.

There are several major factors that seem to influence what species anthros resemble. The best-recognized are:
* Foremost is totemic associations of the parent; an individual who has a strong familial or individual spiritual connection to a particular species or genus of animals is all but guaranteed to have a child of that specioid type, if they do have anthro children. Examples include members of families that have a surname indicating a particular animal, those who have a coat of arms incorporating an animal, or magic users who have deliberately formed a bond with a totemic spirit. It is because of this that there are instances of anthros who have a specioid type of an imaginary or mythical species. This is known as the [i]totemic principle of specioid typing[/i]. This may be forced by deliberate magical and mental association of potential parents hoping to have a child resembling a particular species; it is also the reason that anthros often have children of the same specioid type, especially when both parents are of the same type. Additionally, this appears to be the reason for certain rare types of "hybrids" with a mixed specioid type, where the notion of the possibility of hybridization exists on some level (even where it would be impossible in the actual animal species.
* Second is the birth culture of the anthro in question; experts agree that the morphic field impressions in the coterminous akashic records exert a powerful influence. This is regarded as the reason that anthros may sometimes be born resembling long-extinct and/or even previously undocumented species. This is known as the [i]morphogenetic principle of specioid typing[/i].
* Third is the overall "health" of a species; this includes not only the total population of a species and its viability within its home environment, but recognition of the species by other life. Thus, while there are countless numbers of beetles, with a variety of individual species too great to be properly documented, there are relatively few beetle anthros (as the average person does not give much thought to them); regions where beetles are more culturally important or where they are more visible due to dense populations or great size are much more likely to have occurences of beetle anthros. In contrast, there are large numbers of tiger anthros, despite the relatively small population of non-anthro tigers. This demonstrates the powerful influence of the totemic and morphogenetic principles of specioid typing on this third factor, the [i]population principle of specioid typing[/i]. 
* Fourth is the influence of wholly magical entities as mentioned above. Known as the [i]deliberate principle of specioid typing[/i], it is both the most rare and most powerful, seeming to override any and all other factors.

While the population principle is less likely to impact the occurence of anthros than the other two factors, it has a side effect: the size of the population of anthros of a particular specioid type has a magnifying effect on the health of a species, with members of that species showing improved health across the board, and greater fertility. It is for this reason that there have been several projects to improve the health of threatened or endangered species by using the totemic and deliberate principles to ensure the birth of more children of that specioid type. The most successful instances of this have been with giant pandas, sand cats, mountain gorillas, and cheetahs, with projects underway with kakapos, fossa, and leatherback sea turtles.

Anthropomorphic plants are much rarer than animals, and tend to be the deliberate product of magical sciences; the same goes for anthros resembling a species from any other kingdom of life, as well as the extremely rare viroid anthros. Curiously, anthropomorphic machines are more common; evidence suggests that this has to do with the morphogenetic field being influenced by autonomous movement and by the identification of mechanical actions (particularly those of vehicles) with behaviors of animals. Similar reasons are typically given for anthropomorphic weather or elements. These are all especially likely to occur as a result of protogenesis.