Domestication: If humans hadn't existed, would cats and dogs exist?

[Korn]

[Continued from this thread]

We domesticated ourselves. No one did it to us.

It looks to me that confusion easily can occur if we mix 'humans' with 'we' or 'I'. I was born into domestication, just like 'pets' are.

Most humans that live on the earth today don't live in their natural habitat, we are born into a domesticated situation. 'Unnatural' has become 'normal'. Like domesticated 'pets', most humans can't come and go as they want to, they don't get enough sun because they work indoors most of they time when there's sunlight, they eat highly processed/and unnatural food, they hardly see wild animals or have the chance to eat fresh fruit or wild berries and so on. We didn't domesticate ourselves, our forefathers did. Due to a number of reasons, lots of us would never be able to go back into the wilderness just like that and find a way to survive.

I did not domesticate myself, and the dog I had when I was a kid didn't domesticate itself either. Both humans and animals partly suffer from a lifestyle and limitations imposed upon them by a very unnatural, 'un-wild', life, and 'Modern Man', as we know it, with all its limitation, many 'modern' diseases and frustrations, wouldn't have existed if it wasn't for something that happened in the past.

Originally Posted by Korn
First of all, because 'needing help' doesn't qualify for making humans extinct, it shouldn't qualify for making animals extinct either, and secondly: there aren't so many dogs and cats around because of us; there are so few around because of us.

What? If humans hadn't existed, there wouldn't be *any* dogs and cats.

As I know there isn't any scientific agreement about this, I'd like to hear why you think this is the case. Do you suggest that eg. all dogs, in spite of how different they look, behave etc all are a result of intentional, human cross breeding of wolves?

[ALexiconofLove]

That's how I understand it. From "Origin of the domestic dog" on Wikipedia:

"Prior to the use of DNA researchers were divided into two schools of thought:

1. most supposed that these early dogs were descendants of tamed wolves, which interbred and evolved into a domesticated species.
2. other scientists, whilst believing wolves were the chief contributor, suspected that jackals or coyotes contributed to the dog's ancestry.

Carles Vilà of UCLA,[5], who has conducted the most extensive study to date, has shown that DNA evidence has ruled out any ancestor canine species except the wolf. Vila's team analyzed 162 different examples of wolf DNA from 27 populations in Europe, Asia, and North America. These results were compared with DNA from 140 individual dogs from 67 breeds gathered from around the world. Using blood or hair samples, DNA was extracted and genetic distance for mitochondrial DNA was estimated between individuals.

Based on this DNA evidence, most of the domesticated dogs were found to be members of one of four groups. The largest and most diverse group contains sequences found in the most ancient dog breeds, including the dingo of Australia, the New Guinea singing dog, and many modern breeds, like the collie and retriever. Other groups such as the German shepherd showed a closer relation to wolf sequences than to those of the main dog group, suggesting that such breeds had been produced by crossing dogs with wild wolves. It is also possible that this is evidence that dogs may have been domesticated from wolves on different occasions and at different places. Vilà is still uncertain whether domestication happened once - after which domesticated dogs bred with wolves from time to time - or whether it happened more than once."

It does seem weird that we have so many different kinds of dogs if they all descended from wolves. This article (http://www.abc.net.au/animals/program1/factsheet5.htm) discusses a (non-vegan) experiment with domesticating silver foxes. The changes they underwent in behavior and appearance in just 40 years are pretty surprising. If wolves were domesticated for the first time tens of thousands of years ago, I think it's very possible that we could end up with all the different species of dogs that we have today.

[Korn]

I'll post some excerpts showing that there are several theories about the origins of dogs, but let me first say that in spite of intentional human cross-breeding and domestication, humans haven't 'created' dogs, we have to some degree influenced how Canis animals have evolved.

Wolfs exist in many subspecies and colors - grey, white, black, brown, yellow and red. If I would live in some area dominated by a certain type of wolves, say, 5000 years ago, and a wolf from another type of wolf entered my village and I managed to "create" a wolf that looked like a mix of the two wolves, I don't own or control their offspring, and this kind of action wouldn't give me or humans right to eg. make this new breed go extinct. Wolves have developed through at least 300,000 years, and my attempt to cross breed to types of wolves - or continued attempts of influencing how wolves develop doesn't make the the owner or creator of these animals.

The History of Dog Domestication

Dogs are known to hybridize in the wild with both species of wolf, the coyote and the golden jackal, especially where the wild species is close to extinction. All such hybrids are fertile. However, there is conspicuous lack of records of wolf-dog hybrids from the Middle East, India and China, even though local wolves often inhabit the vicinity of human settlements. In parts of northern Eurasia, populations of wolf-dog hybrids became a serious problem for wildlife management and public safety.Where normal wolf pack structure is still maintained, wolves regularly hunt dogs, often preferring them to any other prey (Dinets & Rotshild, 1997).

[...]

Vila et al. (1997) have compared wolf DNA from 27 populations in Europe, Asia, and North America with DNA from 67 dog breeds worldwide. Not surprisingly, the study found that some dog breeds show traces of recent hybridization with various wolf subspecies. But it also estimated the date of original wolf-dog split as 150-400 thousand years ago. The authors (and many groups that later conducted similar research with similar results) have interpreted this result as the date of the first domestication event, presumably in Sub-Saharan Africa prior to the dispersal of Homo sapiens to other continents. However, to my knowledge, there are no wolf fossils from Sub-Saharan Africa.


[---]
However, the "domesticated wolf" theory has serious problems. Some features of dog anatomy, particularly brain structure, resemble jackals and coyotes, but not wolves. Although the most primitive dog breeds and the oldest feral populations all look similar, they do not particularly resemble wolves, having typical dog anatomy and mostly reddish or yellowish coloration. There is absolutely no archaeological evidence of any transition from wolves to dogs from human sites. And, most interestingly, pariah dogs of Asia are not known to hybridize with sympatric wolves, even where both forms coexist in very close proximity.

A much better explanation for all known facts is that dogs have existed in tropical Asia prior to the arrival of modern-type humans and subsequent domestication (Dinets & Rotshild, 1998).

In a little-noticed publication, Koler-Matznik (2002) summarized evidence that the ancestor of the dog was not the gray wolf, but a closely related, smaller extinct canid. The author suggests Canis (lupus) variabilis, an extinct wolf that occurred in present-day China 100-200 thousand years ago, as the most likely candidate.

From http://archaeology.about.com/od/dome...ns/qt/dogs.htm

Recent mitochondrial DNA studies suggest that wolves and dogs split into different species around 100,000 years ago; but whether humans had anything to do with that, no one really knows. Another recent study suggests that the entire population of dogs today are descended from three females near China about 15,000 years ago; these two competing articles probably represent a reworking of the genetic clock as we become more familiar with the process.

http://en.wikipedia.org/wiki/Dog

Genetic analyses have so far yielded divergent results. Vilà, Savolainen, and colleagues (1997) concluded that the ancestors of dogs split off from other wolves between 75,000 and 135,000 years ago, while a subsequent analysis by Savolainen et al. (2002) indicated a "common origin from a single gene pool for all dog populations" between 40,000 and 15,000 years ago in East Asia. Verginelli et al. (2005), however, suggest both sets of dates must be reevaluated in light of recent findings showing that poorly calibrated molecular clocks have systematically overestimated the age of geologically recent events. On balance, and in agreement with the archaeological evidence, 15,000 years ago is the most likely time for the wolf-dog divergence.

http://8e.devbio.com/article.php?id=223

Many arguments about domestication (see Morey 1994) focus on the notion of intentionality. That is to say, did humans select the traits they wanted (human intention), or did humans merely provide a new ecological niche that the wolves exploited ("self domestication")? In the latter scenario, (Zeuner 1963; Coppinger and Smith 1983) the wolves that became dogs may have started out as scavengers around human camp sites and became accustomed to human handouts. Such debates focus more on what it is to be human (as a manipulator of nature) than on what it is to be a dog. There probably was a reciprocal relationship (something that any dog "owner" can tell us about) between wolves finding a new niche and humans finding a furry friend and helper. Both natural selection and artificial selection may have contributed to wolf domestication.

So whether by human intention or niche exploitation, some wolves have become dogs. How did this occur? In becoming domesticated, wolves have undergone numerous morphological, physiological, and behavioral changes. Morey (1994) finds a common factor in pedomorphosis. The adult dog has retained many of the phenotypic traits of the juvenile wolf. The skulls are broad for their length, and juvenile behavioral traits such as whining, barking, and submissiveness, are retained in the adult dog. Morey considers pedomorphosis as a byproduct of natural selection for early sexual maturity and small body size that would increase the fitness of wolves in exploiting a new ecological niche.

http://www.workingdogweb.com/DogOrigins2.htm

In 1997, UCLA biology professor Robert K. Wayne and his colleagues startled the dog world by announcing that their genetic research suggested dogs were first domesticated as early as 100,000 years ago. They also confirmed that dogs are descended only from wolves, not jackals or coyotes as some had surmised.

Here's an article that suggests that dogs aren't evolved directly from wolves, but from from wolf ancestors:
http://en.wikipedia.org/wiki/Dog

The English word dog, in common usage, refers to the domestic pet dog, Canis lupus familiaris. The species was originally classified as Canis familiaris by Linnaeus in 1758. In 1993, dogs were reclassified as a subspecies of the gray wolf, Canis lupus, by the Smithsonian Institution and the American Society of Mammalogists. "Dog" is sometimes used to refer collectively to any mammal belonging to the family Canidae (as in "the dog family"), such as wolves, foxes, and coyotes. Some members of the family have "dog" in their common names, such as the Raccoon Dog and the African Wild Dog. A few animals have "dog" in their common names but are not canids, such as the prairie dog.


Based on DNA evidence, the wolf ancestors of modern dogs diverged from other wolves about 100,000 years ago,[3][4] and dogs were domesticated from those wolf ancestors about 15,000 years ago.[5] This date would make dogs the first species to be domesticated by humans.
Evidence suggests that dogs were first domesticated in East Asia, possibly China,[6] and some of the peoples who entered North America took dogs with them from Asia.[6]
As humans migrated around the planet a variety of dog forms migrated with them. The agricultural revolution and subsequent urban revolution led to an increase in the dog population and a demand for specialization. These circumstances would provide the opportunity for selective breeding to create specialized working dogs and pets.

http://www.idir.net/~wolf2dog/wayne1.htm

Multiple and Ancient Origins of the Domestic Dog

Mitochondrial DNA control region sequences were analyzed from 162 wolves at 27 localities worldwide and from 140 domestic dogs representing 67 breeds. Sequences from both dogs and wolves showed considerable diversity and supported the hypothesis that wolves were the ancestors of dogs. Most dog sequences belonged to a divergent monophyletic clade sharing no sequences with wolves. The sequence divergence within this clade suggested that dogs originated more than 100,000 years before the present. Associations of dog haplotypes with other wolf lineages indicated episodes of admixture between wolves and dogs. Repeated genetic exchange between dog and wolf populations may have been an important source of variation for artificial selection.

The archaeological record cannot resolve whether domestic dogs originated from a single wolf population or arose from multiple populations at different times (1, 2). However, circumstantial evidence suggests that dogs may have diverse origins (3). During most of the late Pleistocene, humans and wolves coexisted over a wide geographic area (1), providing ample opportunity for independent domestication events and continued genetic exchange between wolves and dogs. The extreme phenotypic diversity of dogs, even during the early stages of domestication (1, 3, 4), also suggests a varied genetic heritage. Consequently, the genetic diversity of dogs may have been enriched by multiple founding events, possibly followed by occasional interbreeding with wild wolf populations.

It's commonly thought that dogs were the first species to be domesticated by humans, which suggests that the development from the original wolf toward what we now call dog may have happened over a period of thousands of years before humans started to domesticate dogs.


http://www.canismajor.com/dog/whtzbred.html

Although the domestication of the dog is shrouded in mystery, many scientists are convinced that dogs developed from wolves that settled on the fringes of human development. Wolves found easy pickings in the garbage heaps near human settlements, and, as the wolves became more accustomed to humans and vice versa, humans probably found equally easy pickings among the wolf cubs. These cubs became pets, cave or hut guardians, hunting companions, and later, livestock guardians and herders.

Once a truce was established between wolves and men - a situation that likely happened over and over again in different parts of the world - people may have started to select wolves to enhance certain traits, and thus created dogs skilled in herding, tracking, guarding, retrieving, and coursing.

Wolves in different parts of the world contributed to development of dogs with different body types and coats. There are several theories about the details.

According to Fogle, four types of wolves contributed to the development of dog breeds:

the North American wolf (with some influence from the Chinese wolf) led to the northern breeds such as Alaskan Malamute and various Eskimo dogs and primitive North American dogs;
the Chinese wolf led to the Chow Chow, prehistoric North American dogs, and the Pekingese and various toy spaniels;
the southern Indian and Middle Eastern wolves led to development of a broad spectrum of breeds from sighthounds to mastiffs; and
the European wolves were the progenitors of the shepherd dogs, spitz breeds, terriers, and gun dogs and through crosses with breeds developed from Asian wolves, of spaniels, bloodhounds, pugs, and bulldogs.
Raymond Coppinger, a dog trainer, breeder, and scientist, believes that this widely-accepted theory is not quite accurate. Coppinger presents his version of the development of dog breeds in his fascinating book Dogs: A New Understanding of Canine Origin, Behavior, and Evolution