# If humans vanished, would dog breeds merge or speciate? **URL:** \ **Category:** Great Debates\ **Created:** [February 3, 2014, 4:07am UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399 "2014-02-03T04:07:26Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [February 4, 2014, 6:31pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/61 "2014-02-04T18:31:52Z")
> [@Voyager](#): > > It would be a textbook example of ring species. I think we’d see speciation at the ends, over time. The survival rates of various hybrids would determine how any splits there are. Whether or not pure breds get outcompeted, there would not be many in subsequent generations, so it wouldn’t really matter. It would be pretty much impossible for feral dogs to establish more than one breeding population. Within two generations there wouldn’t be any more giant dogs or toy dogs. First because those types of dogs would be at a severe survival disadvantage compared to average dogs, and second because the ones that did survive would mate with regular dogs and not solely with other giant/tiny dogs. A chihuahua CAN mate with a great dane, if the chihuahua is the male. The only way we’d see speciation is if there is reproductive isolation. That cannot happen with feral dogs unless there is a physical barrier like dogs on an island. A surviving great dane might not mate with a surviving chihuahua, but the great dane is going to mate with the lab, and the chihuahua is going to mate with the terrier, and the lab/dane is going to mate with the chihuahua/terrier. It isn’t like all the great danes live on one island and all the chihuahuas live on another island and 10,000 years later they can’t interbreed anymore. Dog breeds are thoroughly mixed geographically, and don’t have any behavioral or social barriers to interbreeding. There are enough behavioral and social differences between dogs and wolves that it is possible that dogs and wolves wouldn’t merge back together into one breeding population. ---
**Author:** ![CarnalK](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnalk/32/486_2.png) [@CarnalK](https://boards.straightdope.com/u/CarnalK)\ **Post date:** [February 4, 2014, 6:37pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/62 "2014-02-04T18:37:38Z")
> [@leftfield6](#): > > Against a similar sized wolf pack? Nope. Just my opinion, of course, certainly not willing to run the scientific study needed to prove it. > > IMHO, the wolves have had generation after generation of breeding nothing but survival into themselves. By the time the Rotts have acquired anywhere near this level of survival instinct, they probably aren’t Rotts anymore, based on the crossbreeding that has already been discussed in this thread. I am sorry, but that is silly. Wolves have bred for generations for survival, but that is not the same as fighting skill. Rottweilers are simply stronger. They may not survive as well for a number of environmental reasons but they were bred to be tough. How about a pack of pitbulls, bred specifically to fight other dogs? Still too weak against the wolf? ---
**Author:** ![leftfield6](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leftfield6/32/18780_2.png) [@leftfield6](https://boards.straightdope.com/u/leftfield6)\ **Post date:** [February 4, 2014, 7:01pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/63 "2014-02-04T19:01:45Z")
Neither one of us is ever going to “know” who would win this hypothetical fight, and maybe it comes down to choice of venue, if you will. In the wild, no fighting ring, no barriers, I take the wolf to win. Smart and strong defeats just strong. Stick them in a dog-fighting ring, maybe your pit bull or rottweiler wins. But remember, the premise of the thread is that there are no humans around to stick them in a fighting venue. Here is my reasoning: [ul] [li]typical gray wolf has a big weight advantage on the pit bull, a male gray wolf averages right at 100 pounds[/li][li]Wolf has thick neck fur which helps protect from another predator locking on the neck and ripping. BTW, that is the pit’s preferred attack method.[/li][li]Smarts. The wolf won’t attack the pitbull, it will wait the pitbull out until it starves because it can’t feed itself without it’s master.[/li][/ul] So, in the wild, the wolf wins, but in a staged throw them in a pit fight, maybe it’s even odds. I’d still bet on the animal that didn’t have to be _trained_ to be a killer. ---
**Author:** ![CarnalK](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnalk/32/486_2.png) [@CarnalK](https://boards.straightdope.com/u/CarnalK)\ **Post date:** [February 4, 2014, 7:09pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/64 "2014-02-04T19:09:04Z")
Wait til it starves? Wtf? Look, we were talking about a fight between packs. Wolves or the Pits have killed a deer. Other pack walks up. Who gets the deer? eta: And there is little “maybe” about it in a ring, imho. If wolves would likely win, we wouldn’t have bred pitbulls. We would have bred wolves. ---
**Author:** ![leftfield6](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leftfield6/32/18780_2.png) [@leftfield6](https://boards.straightdope.com/u/leftfield6)\ **Post date:** [February 4, 2014, 7:43pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/65 "2014-02-04T19:43:40Z")
> [@CarnalK](#): > > Wait til it starves? Wtf? > > Look, we were talking about a fight between packs. Wolves or the Pits have killed a deer. Other pack walks up. Who gets the deer? > > eta: And there is little “maybe” about it in a ring, imho. If wolves would likely win, we wouldn’t have bred pitbulls. We would have bred wolves. Agree to disagree. Anyway, back to the thread. Sorry for participating in a rather disturbing wander away from the original question of the thread. ---
**Author:** ![Malthus](https://avatars.discourse-cdn.com/v4/letter/m/85f322/32.png) [@Malthus](https://boards.straightdope.com/u/Malthus)\ **Post date:** [February 4, 2014, 7:48pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/66 "2014-02-04T19:48:23Z")
> [@John\_Mace](#): > > Except that there is a clinal variation in size, so that even if a doberman never mated with a chihuahua, they would each mate with dogs intermediate in size between the two, and so gene flow would continue. And the more successful breed “hybrids” would outcompete the purebreds, bringing us right back to the Pariah Dogs I linked to, above. Does this mean my nightmare vision of a world dominated by packs of vicious teacup chihuahuas is … unrealistic? ☹ ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [February 4, 2014, 7:55pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/67 "2014-02-04T19:55:25Z")
> [@Lemur866](#): > > It would be pretty much impossible for feral dogs to establish more than one breeding population. Within two generations there wouldn’t be any more giant dogs or toy dogs. First because those types of dogs would be at a severe survival disadvantage compared to average dogs, and second because the ones that did survive would mate with regular dogs and not solely with other giant/tiny dogs. > > A chihuahua CAN mate with a great dane, if the chihuahua is the male. The only way we’d see speciation is if there is reproductive isolation. That cannot happen with feral dogs unless there is a physical barrier like dogs on an island. A surviving great dane might not mate with a surviving chihuahua, but the great dane is going to mate with the lab, and the chihuahua is going to mate with the terrier, and the lab/dane is going to mate with the chihuahua/terrier. It isn’t like all the great danes live on one island and all the chihuahuas live on another island and 10,000 years later they can’t interbreed anymore. Dog breeds are thoroughly mixed geographically, and don’t have any behavioral or social barriers to interbreeding. > > There are enough behavioral and social differences between dogs and wolves that it is possible that dogs and wolves wouldn’t merge back together into one breeding population. Actually, lots of dogs do live on islands. Assuming there are enough dogs on an island to establish a viable population, differences in which breeds were present, could bread, and survive would establish geographically diverse populations which would no doubt speciate over time. Dogs would move between islands connected by bridges, until they fall down at least, but not between major Hawaiian islands, not to mention those and the mainland. Or even islands in the Pacific Northwest, like outside of Portland. No problems with wolves or coyotes there either. Maybe then the answer is both. Dogs in large populations will merge, while dogs who are geographically isolated will speciate. We’d wind up with several dog species aft 10,000 years or so or less. ---
**Author:** ![Miller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/miller/32/481_2.png) [@Miller](https://boards.straightdope.com/u/Miller)\ **Post date:** [February 4, 2014, 8:23pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/68 "2014-02-04T20:23:02Z")
> [@Voyager](#): > > Actually, lots of dogs do live on islands. Assuming there are enough dogs on an island to establish a viable population, differences in which breeds were present, could bread, and survive would establish geographically diverse populations which would no doubt speciate over time. Dogs would move between islands connected by bridges, until they fall down at least, but not between major Hawaiian islands, not to mention those and the mainland. Or even islands in the Pacific Northwest, like outside of Portland. No problems with wolves or coyotes there either. Or, for that matter, between continents. Dogs in North America would quickly homogenize, but after fifty thousand years, will they resemble the dogs in Europe any more? ---
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [February 4, 2014, 8:25pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/69 "2014-02-04T20:25:26Z")
A few random thoughts: I think the wolf argument presupposes that the domestic breeds overlap the wolves’ territory and they begin to compete within a generation or two. Not necessarily so in most regions of the USA. As has been said, more likely that coy-dogs with excellent instincts eventually find small areas of existence outside the wolf territory and finally speciate to the local environment. I would think that the Chesapeake Bay retriever might be an exception, at least for several generations. They are so beautifully bred to their environment, and to the purpose of hunting, that I see no reason for them to be threatened by other species for quite some time. They would, of course, breed in with any available females, but their majority attributes are so adaptive, I’d expect the long-term results to be at least identifiable. Bull dogs die out in the first generation, except to the extent that traits of the female survive after mating with smaller male dogs. It would be interesting to know which traits lie on the Y chromosome. We could definitely rule out mass survival of Y-specific traits from very large dogs. (Mastiffs mating at random with small females would produce highly problematic births and low survival rates.) Large skulls in general would be a trait that would die out quickly. In many environments though, the smaller dogs might have the advantage. My dog is a rescue - about 18 pounds. He can stalk a rabbit and touch it with his nose. I feel certain he’d keep us in stew meat if I’d only take him off the leash. I also don’t agree that yellow would be dominant. CeltDog is jet black - completely undetectable at night. This is a huge advantage, especially when competing against sight hounds. And isn’t dark the dominant trait? Also, in any case where food suddenly becomes scarce, smaller more efficient animals will always have the advantage. Natural selection is not necessarily a matter of who wins the fight. It’s a matter of who can grab a fish or efficiently digest the local food source. While I wouldn’t expect to see a lot of wild Chinese Cresteds running around, I’m betting some dachshund traits would be identifiable for a good long time. Further South throughout the Carolinas, Georgia and Alabama, I’d expect to see the hound group do exceedingly well. I wonder about the long hair breeds. I’d expect them to suffer infections at a higher rate, and to be excluded form any water-based food source. ---
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [February 4, 2014, 8:30pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/70 "2014-02-04T20:30:56Z")
Interesting cite re: [Y haplotypes](http://www.ncbi.nlm.nih.gov/pubmed/15965788) (Genetic diversity in domestic breeds - male traits) > [@](#): > > Fifteen breeds were characterized by a single Y chromosome haplotype. Breed-specific haplotypes were identified for 26 of the 50 breeds, and haplotype sharing between some breeds indicated a common history. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [February 4, 2014, 9:10pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/71 "2014-02-04T21:10:23Z")
> [@Voyager](#): > > It would be a textbook example of ring species. I think we’d see speciation at the ends, over time. The survival rates of various hybrids would determine how any splits there are. Whether or not pure breds get outcompeted, there would not be many in subsequent generations, so it wouldn’t really matter. No, because all individuals are inter-fertile. In a ring species, some individuals cannot produce fertile offspring with each other. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [February 4, 2014, 9:15pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/72 "2014-02-04T21:15:21Z")
> [@Voyager](#): > > Maybe then the answer is both. Dogs in large populations will merge, while dogs who are geographically isolated will speciate. We’d wind up with several dog species aft 10,000 years or so or less. Very unlikely, unless there was some dramatic environmental change. Large mammals just don’t speciate in that short a time span. Once people are out of the way, wolves are going to spread across the landmass like wildfire, driving coyotes back to more marginal areas. Or, they are going to be absorbed into one larger breeding population (as is already happening in some areas). There will be a huge drop in dog populations in the first few generations, but the ones that do survive (and there will be LOTS of them) will most likely merge into coyote or wolf populations. Dogs, as dogs, will probably survive only in isolated areas. Why is everyone so sure there is going to be some speciation event so quickly? What would drive that? ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [February 4, 2014, 10:00pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/73 "2014-02-04T22:00:45Z")
> [@John\_Mace](#): > > Very unlikely, unless there was some dramatic environmental change. Large mammals just don’t speciate in that short a time span. > > Once people are out of the way, wolves are going to spread across the landmass like wildfire, driving coyotes back to more marginal areas. Or, they are going to be absorbed into one larger breeding population (as is already happening in some areas). > > There will be a huge drop in dog populations in the first few generations, but the ones that do survive (and there will be LOTS of them) will most likely merge into coyote or wolf populations. Dogs, as dogs, will probably survive only in isolated areas. > > Why is everyone so sure there is going to be some speciation event so quickly? What would drive that? Like I said, geographical isolation. I quite agree it probably won’t happen on land masses with lots of mixing. In nature we don’t start with instantaneous isolation coupled with possible breed diversity. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [February 4, 2014, 10:07pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/74 "2014-02-04T22:07:43Z")
> [@CarnalK](#): > > If wolves would likely win, we wouldn’t have bred pitbulls. We would have bred wolves. Dogs **are** domesticated wolves. And I don’t think pit bulls were bred to fight wolves. ---
**Author:** ![CarnalK](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnalk/32/486_2.png) [@CarnalK](https://boards.straightdope.com/u/CarnalK)\ **Post date:** [February 4, 2014, 11:29pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/75 "2014-02-04T23:29:52Z")
> [@BrainGlutton](#): > > Dogs **are** domesticated wolves. And I don’t think pit bulls were bred to fight wolves. And wolves weren’t bred to fight pit bulls. Their is very little physical threats to wolves in their naturalenvironment. Their fighting of other dogs is almost always to show dominance - not to rip the crap out of the other dog like pit bulls have been bred for. ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [February 4, 2014, 11:57pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/76 "2014-02-04T23:57:03Z")
Right. So a pit bull has some fighting behaviors that make no sense for a social pack animal. Pit bulls continue to fight long after the fight doesn’t make sense, even after horrible injuries. The purpose of a fight between two social animals is to establish which one would win the fight, if the fight keeps on. Once that is established, the fight is over. Think about a pack of pit bulls that won’t give up a fight, compared to a pack of wolves. The pit bulls are going to kill each other off. Even if an individual pit bull could win a fight to the death with an individual wolf when locked in a cage together, the pit bulls are worse off. Their fighting instincts are all wrong and crazy. Crazy insane fighting spirit makes sense if you’re breeding dogs to win dogfights. It doesn’t make sense if you’re a wild social creature trying to survive as part of a pack. Dog fights are only one-on-one within a pack, between packs the dogs/wolves will cooperate with each other. A pack of pit bulls where any disagreement over dominance leads to a fight to the death isn’t going to last very long, and a pack of wolves can easily bring down an individual pit bull. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [February 5, 2014, 12:33am UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/77 "2014-02-05T00:33:16Z")
> [@CarnalK](#): > > And wolves weren’t bred to fight pit bulls. Their is very little physical threats to wolves in their naturalenvironment. Their fighting of other dogs is almost always to show dominance - not to rip the crap out of the other dog like pit bulls have been bred for. You have obviously never seen a pack of wolves tear into a coyote or a stray wolf from another pack. They can rip the crap out of a wolf if they need to. They just rarely need to within their own pack. ---
**Author:** ![CarnalK](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnalk/32/486_2.png) [@CarnalK](https://boards.straightdope.com/u/CarnalK)\ **Post date:** [February 5, 2014, 12:53am UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/78 "2014-02-05T00:53:28Z")
Yeah, as a pack. They can be pretty cowardly when alone. I already admitted that Wolves are the survivors. Their hunting instincts alone give them a massive edge going forward. But I bet if a Pit Bull or Rottie breeding kennel was right next to a sheep farm when the apocalypse hit, it would be some time before wolves figure they could move in. ---
**Author:** ![GoodOmens](https://avatars.discourse-cdn.com/v4/letter/g/d26b3c/32.png) [@GoodOmens](https://boards.straightdope.com/u/GoodOmens)\ **Post date:** [February 5, 2014, 1:43pm UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/79 "2014-02-05T13:43:09Z")
> [@Boogly](#): > > Do you think dogs discriminate now? Does one breed look at another and think ‘oh hell naw’? Given what I saw one Sunday at the dog park between a (very determined) dachshund and a (very bored) mastiff, I’d say there at least some cross-breed doggy-style going on. ---
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [February 6, 2014, 2:29am UTC](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399/80 "2014-02-06T02:29:27Z")
I have seen a German Shepherd bitch reject a smaller dog’s advances. And Siberian Huskies quickly develop strict pack hierarchies, with sub females sometimes physically skipping estrus, but more often going through it without mating. [Previous page](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399.md?page=3) [Next page](https://boards.straightdope.com/t/if-humans-vanished-would-dog-breeds-merge-or-speciate/680399.md?page=5)