How to breed a new species?

How would you classify a new species of dog? The problem seems to have more to do with semantics than any physical differences. If the only qualification necessary to label species separate was inability to breed, we could probably achieve that within a lifespan (perhaps with a little help from GM).


It is possible to notice the effects of selective breeding within the last century. IF you can change the shape of a cats nose within fifty years, think of how much change a fifteen millenia of selective breeding would incur. Hehehe. You could create your own race of superbeasties (although perhaps genetic engineering is a quicker way to play with nature).

Regarding genetic similarities :Cross breeding would have to be taken into consideration. It's only in the past century or three that people have been so fussy about keeping breeds pure (and, even then, there has been an enormous amount of cross breeding). Through travelling, we've just destroyed fifteen millenia of genetic divergence. Damn! Oh well, time to start again. We can probably do it a lot faster if we fiddle add some giraffe genes :wink: ..

Would anybody like to create a new superbeastie with me? Disclaimer : As you can probably tell by now, my expertise on this subject is yr 12 biology, 1970s science fiction novels and a childhood obsession with dogs. It is possible that the superbeastie would produce enough slobber to drown all of humanity.

I believe a new breed only requires 10 generations of consistent attributes to be considered a new breed by akc. What do you mean by new species?

Good question. In general usage, things are considered to be different species when they can no longer mate and produce fertile offspring.

So, how long might it be before any given breed of dog became so different from any other breed, that they could could no longer mate to produce fertile offspring, thus implying that a new species of dog had evolved. And would that then be two new species, or one new species?

Since mutations are random, it is not possible to predict exactly how long it would take for one or mutations to occur which would prevent species from crossbreeding.

Populations can be considered different species even though they are able to interbreed. For instance, male wolves can and do mate with female coyotes and produce fertile offspring.

Interbreeding threatens rare species

Not all breeds of dogs can crossbreed with wolves. If a male chihuahua could neither attract a female wolf nor physically mate with her, they are certainly different species.

Hi Terry,

I didn't expect a precise answer. I was more interested in understanding the comparitive relationship between artificial selection in dogs and natural selection over time.



Then what defines a "species"?

hmm interesting

The Chihuahua example reminded me of an interesting memory (I hope interesting): I have a 3 1/2 pound male MI-KI named Drago. He is the gentlest animal you will ever see, but having never known fear, he doesn't seem to realize he is small. Once, when my neighbor's 75 pound female was in heat, the strangest thing occurred. When he approached in the ritual fashion, she dutifully dropped to her side to accommodate him. As he approached though, she nipped at him and I though he was a goner. It just blew me away that an animal 20 times his size would have laid down in the first place.

If we use this (above) as a definition of species, then Chihuahuas and wolves are already different species.

But I'm more interested in a level of differentiation in which the genetics are no longer viable for reproduction. And I'm interested in imagining how such a difference in genetics might show up physically. After all, a Chihuahua still looks like a dog, even though it's attributes are extreme. But (after eons off selective breeding) when it finally stops being a Canis Lupus Familiaris (at a genetic level), what might it look like? What characteristic might it have that would make it anything other than a dog?

I'm trying to explore two ideas here:

1. The timeframe involved in artificially selecting changes until the divergence shows up at the genetic reproductive level (different species by genetics).

2. What level of genetic change is most likely to result in species divergence? For instance, does body size selection lead to divergence more rapidly than, say... selection for digestive differences (a dog that had more omnivorous traits, rather than carnivorous traits)? Another way of saying this might be, "Is species divergence more driven by surface structural changes, or by deeper/older genetic designs like digestion or tooth size?"

Thanks,

I was thinking along the line of Occum. Very large and very small could conceive by artificial insemination. Likely most of the pups would die at birth or shortly after, but an occasional pup would survive and breed. Breeders are however searching for desirable traits, not just different. Dogs seem to be very versatile. Perhaps a new species could be produced easier from raccoons or some other species. Neil

There is no simple definition of species, since it depends on what characteristics you focus on:

species: An important classificatory category, which can be variously defined by the biological species concept, cladistic species concept, ecological species concept, phenetic species concept, and recognition species concept. The biological species concept, according to which a species is a set of interbreeding organisms, is the most widely used definition, at least by biologists who study vertebrates. A particular species is referred to by a Linnaean binomial, such as Homo sapiens for human beings.

cladistic species concept: The concept of species, according to which a species is a lineage of populations between two phylogenetic branch points (or speciation events).

ecological species concept: A concept of species, according to which a species is a set of organisms adapted to a particular, discrete set of resources (or "niche") in the environment.

phenetic species concept: A concept of species according to which a species is a set of organisms that are phenotypically similar to one another.

recognition species concept: A concept of species according to which a species is a set of organisms that recognize one another as potential mates; they have a shared mate recognition system.

ring species of warblers

I wonder if canines could be considered ring species? Does anyone know if toy dogs ever successfully breed with saint bernards? Body size matters if they are physically unable to mate and bear puppies. Mating behavior and reproductive cycles (wolves only come into season once a year) are probably more important for separating species.

Differences in digestion, tooth size, coloring, etc. would lead to populations inhabiting different ecological niches, possibly keeping them from meeting or being inclined to mate.

We could probably produce canine speciation on a genetic level by inducing mutations and selectively breeding the resulting puppies, but it would be expensive, time-consuming, and there would be a lot of wastage. A lot of work has been done with lab mice, but I am not aware of any new species being produced.

Hi Terry, thanks for the feedback.



I've always suspected that a male toy would mate with a female large dog if given the chance (female dogs in heat seem to demand attention from all male dogs), though the coupling might be reminiscent of something more arachind than canine.

In any case, I suspect that large dog could get pregnant from a much smaller animal, and deliver pups (which might not be possible the other way around due purely to size problems).



Yes, this is the natural process. But we are essentially replicating that process artificially by inducing controlled/limited breeding situations. Since our artificial process is essentially the same as the natural one, the same result could logically be expected over a long enough time. This is what led me to ask the question.

Then I began to wonder what *type* of genetic variation/mutation would be more likely to produce new species? Would it be those "surface" features like ear shape and color, or would it be more ancient designs like digestion?



Yes, the same questions would apply to mice as well. And we *have* been producing breeds by exploiting natural mutation and natural variation. If we continue the process might we eventually get an entirely new species (genetically), and not just a breed?

Thanks,