Naked Science Forum

General Science => General Science => Topic started by: neilep on 11/04/2007 03:28:31

Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: neilep on 11/04/2007 03:28:31
This is a chiwawa:

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fimg.photobucket.com%2Falbums%2Fv286%2Fneilneil%2Fchiwawa-f-koinu.jpg&hash=fa47ddf55a9e3ce4c79a0d8ebda5dd8e)

This is a Great Dane and another Chiwawa:

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fimg.photobucket.com%2Falbums%2Fv286%2Fneilneil%2FIMG013biglittledogFX_wb.jpg&hash=f37c0b14c1e13c8727893e2bad4f67c0)

This is an Old English Sheep dog:

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fimg.photobucket.com%2Falbums%2Fv286%2Fneilneil%2FOldEnglishSheepDog-L.jpg&hash=ad7af236f992fee2a54becbed3e0fefe)


This is a bunch of Peeps:

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fimg.photobucket.com%2Falbums%2Fv286%2Fneilneil%2Fcrowds_inside.jpg&hash=917ccce68b0374eb9a06dbb4e7215590)

Notice how all the Peeps look very similar in stature and build etc ?


Why are there more varieties on such a grand scale of canines  (and other animals like bears, primates)....than there are humans ?...or perhaps my question should be...why are there less varieties on a grand scale of humans than there are other types of animal ?
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: JimBob on 11/04/2007 03:54:51
I guess Samuel (Peeps, that is - I know, it's Peyps) like the same type of women and only, how do I say it, propagated, his line with very similar looking women.
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: Karen W. on 11/04/2007 04:11:48
I don't know Is that a shot from one of your wedding fayres?
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: another_someone on 11/04/2007 04:21:59
One explanation I have heard is because dogs have more chromosomes to play with, so can have more combinations of genes to mix up.

But, at least as much of an issue is that dog breeds are totally artificial - we deliberately inbreed dogs with certain characteristics to develop the different breeds.  We do not in general implement the same deliberate breeding programs to create the same variety of human breeds.

Dogs, if left to their own natural breeding habits will revert to all being something like wolves or dingos.
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: BillJx on 11/04/2007 05:23:57




 - we deliberately inbreed dogs with certain characteristics to develop the different breeds.  We do not in general implement the same deliberate breeding programs to create the same variety of human breeds.

Dogs, if left to their own natural breeding habits will revert to all being something like wolves or dingos.

To start with an intelligent, competent animal and deliberately breed it in such a way as to render it unfit to be anything but a living toy, I think is a crime of arrogance.
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: another_someone on 11/04/2007 07:08:48
To start with an intelligent, competent animal and deliberately breed it in such a way as to render it unfit to be anything but a living toy, I think is a crime of arrogance.

It depends on the dog.  A rotweiler or a sheepdog is bred as a working dog, and certainly not merely a toy (maybe a slave, but not a toy).

But then, selective breeding is not only something we do for dogs - we do the same for cattle, sheep, and numerous other species of animals (even the European honey bee has been selectively bred).
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: DoctorBeaver on 11/04/2007 08:46:03
- we deliberately inbreed dogs with certain characteristics to develop the different breeds.  We do not in general implement the same deliberate breeding programs to create the same variety of human breeds.

Dogs, if left to their own natural breeding habits will revert to all being something like wolves or dingos.

To start with an intelligent, competent animal and deliberately breed it in such a way as to render it unfit to be anything but a living toy, I think is a crime of arrogance.

Arrogance or not; so long as the animal is happy & well looked after, that's all that matters.

Seeing a border collie shepherding or a Rottweiller rounding up cattle is a joy to behold. OK, so they were deliberately bred; but you will never see happier animals than those 2 breeds when they're working.
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: Bored chemist on 11/04/2007 11:18:33
OK, ignoring the problem of defining "happy" for non human species, there are some breeds of dogs that have been taken to such extremes that they are prone to various diseases. That's criminal if you ask me.
BTW, the cattle are working too; how happy are they to be chased by a rottweiler?
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: daveshorts on 11/04/2007 12:58:09
Basically dogs have been very strongly bred for their physical characteristics. If you just let very tall people breed with other very tall people, you would quite quickly get a race of very tall people.

Whether you could get the variation of size you can with dogs, I am not sure, because humans are genetically very uniform - I think there is more genetic variation in mountain gorrillas than humans - so there is a lot less diversity to work with than in a wolf, so you probably couldn't push humans as far with selective breeding - essentially we are a very highly bread hominid breed that has been selected for a large brain.
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: another_someone on 11/04/2007 13:00:25
OK, ignoring the problem of defining "happy" for non human species, there are some breeds of dogs that have been taken to such extremes that they are prone to various diseases. That's criminal if you ask me.

I would suggest that defining 'happy' for non-human species is no more difficult that defining 'happy' for a 4 month old child, and it is scarcely easier to define 'happy' even for an adult.

One thing we can at least say is that when an animal is clearly sufferring, we tend to put it out of its misery - something we refuse to do for humans.

As for whether it is right to unnecessarily inbreed dogs that are particularly prone to some illnesses - in general, (although I would not use the word criminal - since that is a word with a very precise meaning) I would agree that I am uncomfortable with the idea, but there are many analogous (although not identical) questions that can be applied to human experience too.

BTW, the cattle are working too; how happy are they to be chased by a rottweiler?

Probably the same way that a child feels when it is angrily told to go to school (bear in mind that the dogs do not physically harm the animals they are herding, any more than a decent parent physically harms its child).
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: neilep on 11/04/2007 13:27:02
I guess Samuel (Peeps, that is - I know, it's Peyps) like the same type of women and only, how do I say it, propagated, his line with very similar looking women.


How he managed to woo women, write a diary and single handedly extinguish the fire of London is worthy of BIG respect !!
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: neilep on 11/04/2007 13:29:31
I don't know Is that a shot from one of your wedding fayres?

yes it is !!..can't ewe see all the brides and wedding cakes ?...LOL...no ..it's just some piccy of a crowd I found !!

wedding fayres are a little more discrete with all fluffy wedding stufff all over the place !!
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: neilep on 11/04/2007 13:36:17
One explanation I have heard is because dogs have more chromosomes to play with, so can have more combinations of genes to mix up.

But, at least as much of an issue is that dog breeds are totally artificial - we deliberately inbreed dogs with certain characteristics to develop the different breeds.  We do not in general implement the same deliberate breeding programs to create the same variety of human breeds.

Dogs, if left to their own natural breeding habits will revert to all being something like wolves or dingos.

Thank Ewe for this George.

Any ideas what the ratio is to pure breeds to ' artificial' ones are ?

I assume there must be a ' foundation template' of a few thoroughbreds ?

Could the ratio be as high as i think it might ?.(Wild guestimate 80:20)........in that I expect there to be far more ' manufactured ' breeds than thoroughbreds !!......but what about other types of multi-variety animal ?
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: neilep on 11/04/2007 13:42:14
OK, ignoring the problem of defining "happy" for non human species, there are some breeds of dogs that have been taken to such extremes that they are prone to various diseases. That's criminal if you ask me.
BTW, the cattle are working too; how happy are they to be chased by a rottweiler?

There is no doubt that there are types of dog that are  bred for the cosmetic fancy of their owners.....and often to the detriment of the dog itself. I can not remember the breeds but there are some that can barely walk as their legs are so short, they can barely breathe...........they can barely do anything except be an ornate adoration.
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: paul.fr on 11/04/2007 13:59:00
pink poodles...what are they all about?
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: another_someone on 11/04/2007 14:17:07
Any ideas what the ratio is to pure breeds to ' artificial' ones are ?

I assume there must be a ' foundation template' of a few thoroughbreds ?

Could the ratio be as high as i think it might ?.(Wild guestimate 80:20)........in that I expect there to be far more ' manufactured ' breeds than thoroughbreds !!......but what about other types of multi-variety animal ?

As far as I am aware, there is only one natural breed of dog, and that is the wolf, and everything else is an artificial breed.

Clearly, there is some variety amongst wolves, but none of that variety directly correlates to a modern breed of dog.

Trying to find a natural breed dog is like trying to find a natural breed of cow - no domestic animal is ultimately natural.
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: neilep on 11/04/2007 14:26:49
Any ideas what the ratio is to pure breeds to ' artificial' ones are ?

I assume there must be a ' foundation template' of a few thoroughbreds ?

Could the ratio be as high as i think it might ?.(Wild guestimate 80:20)........in that I expect there to be far more ' manufactured ' breeds than thoroughbreds !!......but what about other types of multi-variety animal ?

As far as I am aware, there is only one natural breed of dog, and that is the wolf, and everything else is an artificial breed.

Clearly, there is some variety amongst wolves, but none of that variety directly correlates to a modern breed of dog.

Trying to find a natural breed dog is like trying to find a natural breed of cow - no domestic animal is ultimately natural.

Have you met my wife ?
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: elegantlywasted on 11/04/2007 15:26:35
English Bulldogs cannot breed naturally anymore. Their bodies do not allow for the actual act to take place, and because their heads have been designed to be so large they can only be delivered by C-Section.
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: Seany on 11/04/2007 16:01:42
Hmm, not so long ago, there was an article on the newspaper on this. Darn, I forgot to read it though  [:P]
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: Karen W. on 11/04/2007 16:13:13
I don't know Is that a shot from one of your wedding fayres?

yes it is !!..can't ewe see all the brides and wedding cakes ?...LOL...no ..it's just some piccy of a crowd I found !!

wedding fayres are a little more discrete with all fluffy wedding stufff all over the place !!

Thats alot of people wherever it is!
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: Karen W. on 11/04/2007 16:20:35
pink poodles...what are they all about?

Hey there was this Lady, when I was a kid she lived in Eureka by the sequoia park,..She lived in a pink and white singlewide trailer house well kept very clean, with a little white short pickette fence around her yard. She owned a , I kid you not pink poodle who was well groomed with hot pink bows on each ear. Pink rhinestone studded color and leash. She drove a nice big Pink catalac and get this dyed her own hair pink to match her dogs pink hair.. I used to love to see her so much.. I was sad when she either died or moved, I was young so I don't know what happened I thought she was too cool!! LOL Always smilen and always so friendly! I loved her !! LOL
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: another_someone on 11/04/2007 16:35:07
I don't know Is that a shot from one of your wedding fayres?

yes it is !!..can't ewe see all the brides and wedding cakes ?...LOL...no ..it's just some piccy of a crowd I found !!

wedding fayres are a little more discrete with all fluffy wedding stufff all over the place !!

Thats alot of people wherever it is!

Three brand names visible in the shot are Fairlight, B&H, and EAW.

Fairlight is into audio-visual equipment, and the other two are audio companies.  Fairlight and B&H are both Australian companies.

Thus I would suspect it is an audio-visual exhibition somewhere in Australia - but that conclusion must be regarded as speculative.
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: that mad man on 11/04/2007 20:10:11
Pink poodles and an audio fair................cant resist!

In a Noel Coward double entendre stylee.


I'd love to be a pink poodle in panties,
and get stroked by my friends all day,
a lovely pink poodle in panties,
I wouldn't want it any other way,

With a diamond collar round my neck,
and a matrix by my side
playing with my bone,
that is sometimes hard to hide,

I'd love to be a pink poodle in panties
and play with my friends all day.

 [:o]

TMM

Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: neilep on 11/04/2007 20:20:44
Pink poodles and an audio fair................cant resist!

In a Noel Coward double entendre stylee.


I'd love to be a pink poodle in panties,
and get stroked by my friends all day,
a lovely pink poodle in panties,
I wouldn't want it any other way,

With a diamond collar round my neck,
and a matrix by my side
playing with my bone,
that is sometimes hard to hide,

I'd love to be a pink poodle in panties
and play with my friends all day.

 [:o]

TMM



QUALITY !!!
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: Carolyn on 11/04/2007 20:21:03
Pink poodles and an audio fair................cant resist!

In a Noel Coward double entendre stylee.


I'd love to be a pink poodle in panties,
and get stroked by my friends all day,
a lovely pink poodle in panties,
I wouldn't want it any other way,

With a diamond collar round my neck,
and a matrix by my side
playing with my bone,
that is sometimes hard to hide,

I'd love to be a pink poodle in panties
and play with my friends all day.

 [:o]

TMM



Haha.  Nice! [;D]
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: Seany on 11/04/2007 21:12:30
Pink poodles and an audio fair................cant resist!

In a Noel Coward double entendre stylee.


I'd love to be a pink poodle in panties,
and get stroked by my friends all day,
a lovely pink poodle in panties,
I wouldn't want it any other way,

With a diamond collar round my neck,
and a matrix by my side
playing with my bone,
that is sometimes hard to hide,

I'd love to be a pink poodle in panties
and play with my friends all day.

 [:o]

TMM



Lol [:D]
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: JimBob on 12/04/2007 04:02:05
Any ideas what the ratio is to pure breeds to ' artificial' ones are ?

I assume there must be a ' foundation template' of a few thoroughbreds ?

Could the ratio be as high as i think it might ?.(Wild guestimate 80:20)........in that I expect there to be far more ' manufactured ' breeds than thoroughbreds !!......but what about other types of multi-variety animal ?

As far as I am aware, there is only one natural breed of dog, and that is the wolf, and everything else is an artificial breed.

Clearly, there is some variety amongst wolves, but none of that variety directly correlates to a modern breed of dog.

Trying to find a natural breed dog is like trying to find a natural breed of cow - no domestic animal is ultimately natural.

There are about 30 types of wild canines. The African Wild dog is obvious. But foxes are also Canines. There are 20+ species of foxes.  Here is what WIki.. says about the African dog:

"The African Wild Dog, Lycaon pictus also known as the African Hunting Dog, Cape Hunting Dog, or Painted Hunting Dog, is a mammal of the Canidae family, and thus related to the domestic dog. It is the only species in monotypic genus, Lycaon, and the only species in the canid family to lack dewclaws on the forelimbs. They are, as their name indicates, found only in Africa, especially in scrub savanna and other lightly wooded areas. The Latin name of the species means painted wolf and it is characteristic of the species that no two individuals have the same pattern of coat. Individuals can easily be recognized in the basis of coat patterns. The pelage is an irregular pattern of black, yellow, and white. Their coats are sparse in comparison to canids in temperate zones, and the skin is black."

Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: JimBob on 12/04/2007 06:32:09
Dang! DON'T FORGET THE COYOTE!

The coyote (Canis latrans, meaning "barking dog"), also prairie wolf, is a member of the Canidae (dog) family and a close relative of the domestic dog. In have seen one here in the city. Duh!

Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: another_someone on 12/04/2007 09:57:02
Foxes are indeed a different species of the dog family, but as such, they cannot interbreed with domestic dogs.

Wolves can interbreed with domestic digs, and are thus not merely a different species of the same family, they are indeed the same species, but merely a different breed.
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: JimBob on 12/04/2007 10:01:00
Coyotes DO interbreed with the common dog. They are also a different species.
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: another_someone on 12/04/2007 10:30:36
Coyotes DO interbreed with the common dog. They are also a different species.

This is where we get to ambiguities about species.

If cayotes can interbreed with the common dog (and I assume can also interbreed with wolves), the why are they regarded as a distinct species (except maybe out of tradition - the first guy who saw them regarded them as a distinct species, and nobody ever corrected him - but then, if an alien first saw a Chihuahua and a Great Dane, they would probably have regarded them as distinct species also - this is why I am always very sceptical about some of the counts used for the numbers of species that exist, and thus the number of species that become extinct.
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: JimBob on 12/04/2007 11:12:26
Coyotes have a much different genetic make-up than dogs. Interbreeding is allowed because of gene number - when the zygotes are able in may cases to survive. Obviously, a horse and a donkey(ass)are different species. A donkey's coat is not waterproof. Asses are still found in the wild while horses are not. But these two different species can interbreed. The result is a donkey. There is one known example of an artificial insemination cross between a lion and a tiger. Alpacas and Llamas have been interbreed by ranchers in order to obtain a finer type of wool on an animal larger in size than an alpaca. There are many other types of examples in nature where the meeting of two species has led to other species - corals, fish, etc.

But the point you make about what differentiates a species begs the question of are there other types of dogs. There obviously are, or the African Wild Dog would not be named as it is. Jackals are also closely related to wolves. They were domesticated - at least breed - by the Egyptians. And, if you look up wolf taxonomy, there are more than 17 different sub-species that are differentiated. None that share habitat with each other will interbreed. So what is a species? The American Red wolf, not listed in Wiki, is being driven out of it's habitat and going to extinction from competition with the grey wolf or plains wolf. If lack of interbreeding describes difference in species then there should be 17 + wolf species. Taxonomy today is dependent on genetic sequencing. I am no expert on sequencing so I cannot speak to genetic taxonomy. But the old idea of if it interbreeds, it must be the same species and if it doesn't interbreed it is a different species was dead in the early '80's.

Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: another_someone on 12/04/2007 13:54:13
Coyotes have a much different genetic make-up than dogs. Interbreeding is allowed because of gene number - when the zygotes are able in may cases to survive. Obviously, a horse and a donkey(ass)are different species. A donkey's coat is not waterproof. Asses are still found in the wild while horses are not. But these two different species can interbreed. The result is a donkey. There is one known example of an artificial insemination cross between a lion and a tiger. Alpacas and Llamas have been interbreed by ranchers in order to obtain a finer type of wool on an animal larger in size than an alpaca. There are many other types of examples in nature where the meeting of two species has led to other species - corals, fish, etc.

Mules (the cross between a horse and donkey) does exist, but is sterile.  Male ligers and togons are sterile, although the females are fertile.  Clearly, in none of these cases can a cross be considered a viable branch of either of the parent species.

But the point you make about what differentiates a species begs the question of are there other types of dogs. There obviously are, or the African Wild Dog would not be named as it is. Jackals are also closely related to wolves. They were domesticated - at least breed - by the Egyptians. And, if you look up wolf taxonomy, there are more than 17 different sub-species that are differentiated. None that share habitat with each other will interbreed. So what is a species? The American Red wolf, not listed in Wiki, is being driven out of it's habitat and going to extinction from competition with the grey wolf or plains wolf. If lack of interbreeding describes difference in species then there should be 17 + wolf species. Taxonomy today is dependent on genetic sequencing. I am no expert on sequencing so I cannot speak to genetic taxonomy. But the old idea of if it interbreeds, it must be the same species and if it doesn't interbreed it is a different species was dead in the early '80's.

http://en.wikipedia.org/wiki/Red_Wolf
Quote
For decades, the Red Wolf has been indistinguishable genetically from either the Gray Wolf or the Coyote. The Red Wolf breeds with both species and may again be in peril as contact with other species in the wild resumes

http://en.wikipedia.org/wiki/Canis
Quote
Canis is a genus that includes several of the modern wolf and jackal species, including the Gray Wolf (Canis lupus) which is thought to be the ancestor of the Domestic Dog (Canis lupus familiaris). There are between 7 and 10 species, depending on the source that is used. The jackals used to be placed in their own genus: Thor, but that classification is never used now. Molecular evidence indicate that Cuon (Asiatic wild dog) is actually part of Canis. Other closely related genera are Lycaon (African wild dog) and, more distantly, Pseudalopex and other South American Foxes.

In other words, if the Wikipedia entry is correct, the African Wild Dog is more distant from domestic dogs than is the grey wolf - so the use of the term 'dog' in the name should not be regarded as any indication of taxonomic proximity.

While I agree that DNA is used to determine taxonomic relationships, but I am not aware that we are yet sufficiently advanced in understanding the DNA to determine species delineation (i.e. we can say that A is more closely related to B than to C, but I was not aware that from DNA alone we can yet say whether A and B are two breeds of the same species, or two distinct species - although in the case of the Red Wolf, it does seem that the DNA is so close to the grey wolf and the coyote, that it is on that evidence alone the same species).
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: neilep on 12/04/2007 14:41:05
THANK YOU BOTH GEORGE & JIMBOB


This is very interesting.

Can a Chihuahua do  'the deed ' with a Great Dane then ?

Will the offspring be the same whether the Chihuahua is the mummy or daddy ?
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: another_someone on 12/04/2007 15:40:19
One of the problem with the idea of species is that it has become political.  If the Red Wolf is regarded as a distinct species, then you can claim protection for it as an endangered species, but if it is only regarded as a breed, then it loses that legal protection, and so the word you use has not only scientific significance but also political significance.
Title: Why are we (humans) not as varied in shape and size like dogs ?
Post by: Seany on 12/04/2007 15:42:11
*Nods head frantically*