Assuming it’s only a matter of mixing the egg and sperm and putting the embryo someplace to grow where it won’t cause a problem, at what degree of separation is it no longer possible for two kitties or two dogtypes to breed? We’ve seen ligers and wolfdogs, where does it stop?
Can a male housecat successfully fertilize the eggs of a bobcat? Panther? Lion? Wiki says there are two families: Pantherinae, and Felinae - since we invent those classifications, what do we base it on? Can the two families cross? Can they interbreed within the family?
Can a male chihuahua successfully fertilize a female wolf? A coyote? A fox? A jackal?
And if the size issues are actually issues and a Bichon frise can’t impregnate a wolf, can a Lab fertilize a coyote? Can a fox fertilize greyhound or a jackal a bulldog? Leaving out the domestics, can a jackal fertilize a fox?
Are there any recorded instances of wild canids or wild felids crossing species lines on their own?
And yes, seeing as this is all science, it’s all available in incredible depth on the web, in Wiki itself, but the depth is the problem. I started to follow some of the links for the definitions of the terms being used and it got very elaborate…more than I wanted. I’m sure some Doper can distill it to the good parts.
Not exactly, from what I’ve been given to understand. No cite at hand, but it’s my impression that most intrageneric cross-species crosses are viable among the canids and felids, with the majority of them producing fertile offspring as well (i.e., not “muling out”). Cross-genus matings are infrequent and AFAICT don’t normally produce offspring.
So dog x wolf or either x coyote works. Any of the above with red fox does not – but red fox x gray fox does. Likewise crosses within Felis, Panthera, and so on will work – but not, usually, crosses between cats [broad sense] in different genera.
My understanding is that all members of the genus Canis are interfertile, and the hybrids are also fertile. This includes wolves (and domestic dogs and dingos, which are derivatives of wolves), coyotes, and jackals. Members of other genera of canids, such as the foxes, do not in general produce hybrids with Canis, but may produce hybrids within their own genus.
The big cats, Panthera, produce viable hybrids within the genus, but the hybrids are for the most part sterile.
Domestic cats will produce hybrids with some other species of small cats in the genus Felis (in the broad sense; some of these species are sometimes classified in other genera), and some of these are fertile. I am not sure to what extent it is known these various small species can cross.
Wikipedia on the Family Felidae gives one common classification system. (FWIW, the one I learned puts all the “great cats” – including jaguar but excluding puma) in Panthera, all the smaller cats up to and including the puma in Felis, recognizes only Neofelis among the assortment of other genera, and puts Acinonyx (the cheetah) as an outlier, in a separate subfamily Acinonychinae. (Cheetahs, specialized for speedy hunting, seem to have set out to answer the question, “How many anatomical differences can be introduced from other cats and still remain a cat?”) So take th Wikipedia article with a grain of salt – it represents A common classification of the cats, but not the agreed consensus classification – there isn’t one, to the best of my knowledge.
Wikipedia on Canidae. (I was in error above in putting red and gray foxes in the same genus as one of my examples.) I don’t know of any major disagreements on this taxonomic scheme, though like any classification there are always arguments among the experts on details. Some older classifications still maintain the dog as a separate species; I think there’s a consensus that it’s a subspecies of Canis lupus now.
While in general I concede your point, John, in this particular case C. lupus is a very diverse species, and dogs, dingoes, and some other “they’re really wolves but called something different” forms are classed as subspecies within it.
Yes, I thought about that as I posted. But I think the solution is to put them in the subspecies of the population from which they were derived. The point being to not created a distinct subspecies for the domesticated variety.
As a practical matter, domestic dogs are often referred to as Canis lupus familiaris, but this is more a matter of tradition and convenience than a reflection of their actual formal taxonomic status. For one thing, a true subspecies is 1) confined to a specific geographical area, and 2) is defined according to some morphological feature that all or most members of the subspecies share and by which they differ from other subspecies. Neither is true of domestic dogs, which obviously occur all over the world, including areas where the ancestral species is found, and which are not united by any single characteristic. It’s probably simply best to consider them a “variety” of Canis lupus rather than call them a subspecies.
Yes, but not by natural breeding. But if done via artificial insemination, they are inter-fertile. Also, for a chihuahua female, there would likely be problems in carrying & birthing just because of physical size. So you might need a c-section birth, or a St. Bernard host-mother.
But you could produce such cross-bred puppies. Of course, the AKC would not accept them, in either breed. So they would be very expensive, unregisterable mutts.
And yet, there is evidence that dogs and wolves really are different genetically. I saw this on a TV show, so I can’t provide a cite, but researchers raised a group of wolves as pets and tested them against dogs of all ages, including young puppies. From a very early age, dogs pick up signals from humans. Dogs, even very young puppies, will look for something they want where a human points; wolves do not. Wolves will continue to problem-solve on their own for a long time; dogs will try for a minute, then sit back and look at a human with the patented “Oh, please, I want it so bad, won’t you help me?” look. Remember, this testing was with wolves that had been raised exactly as if they were dogs, and in the vast majority of ways, they behaved exactly as dogs do, including showing great affection toward their humans. Unfortunately, dingoes were not included in the testing, so I don’t know about them, nor do I know about wolf-dog crosses.
It seems evident to me that dogs are a genetic subset of wolves that has truly adapted to life with humans. Even chimpanzees raised by humans don’t get the concept of following a pointed finger, but dogs do, apparently right from puppyhood, which means it’s not entirely learned behavior.
The wolves were NOT raised the same – they were not suckled by a mother who was trusting & devoted to humans, but the dog puppies were. Young animals learn a lot from their mother; one of the first things they learn is who is a safe & trustworthy helper, and who is a danger. Both sets of puppies are learning from their mothers, and the mother wolf & mother dog look at the human differently.
In raising horses, it’s quite common for foals to develop habits & personalities similar to the mares that raise them. Two years later, as the foal starts in training, you can often see reactions similar to when their mother was trained, many years before. And that isn’t genetic – an orphan foal, raised by another mare, will show traits of that mare, even without any genetic relationship.
Regarding cats, somebody on this message board once said that it was possible for housecats to produce fertile offspring from other felines that are more or less the same size if slightly bigger. I’d asked about this at the time, because we had a 25# tabby which we’d found as a stray kitten. In particular, his teeth and claws were much bigger than anything we’ve ever seen on any other pet cat. To be honest, he was probably a good 7 pounds or so overweight, but had he been at his optimal weight, the superior development of the teeth and claws would have only been thrown into sharper relief.
But I haven’t been able to find any documented evidence on this subject.