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Mick Harper
Site Admin
In: London
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But how wild is the vicuna? Don't they have vicuna wool? I've never heard of catching a wild animal for its wool. But come to think of it, why not?
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Martin
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They do indeed have vicuna and guanaco wool. It is very expensive because they produce so little.
The key thing is orthodoxy/wikipedia says :
| There are no wild alpacas; they were bred down in domesticated form from the vicuña, which is also native to South America. They are closely related to llamas, which are descended from the guanaco. |
Both the guanaco and the vicuna are smaller than their domesticated cousins.
So there is a problem. The rule of thumb "domesticated animals are smaller than their wild cousins" or the orthodox history of the New World Camelids?
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Mick Harper
Site Admin
In: London
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You're entering into the spirit of things, Martin. My reading of the Wikipedia entry is that nobody has a clue about what is wild, what is domesticated and what is feral down South America way. Much less who is bigger than whom.
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Komorikid
In: Gold Coast, Australia
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| Where have fossil horses actually been found? Komori? Did they simply not have them that far south, the Great Plains having the monopoly? Where they had llamas, they used llamas. |
May 3, 2001 - Calgary News
Canadian scientists have uncovered what they say is the first unequivocal evidence that prehistoric North Americans hunted and butchered now-extinct horses.
Several of the horse's vertebrae were smashed and it had what appeared to be butcher marks on a number of its bones.
Although archaeologists have long suspected the "big game" hunters of the Clovis period (9000-10000 BC) of hunting the horses, there has been little evidence to support this theory until now.
This sums up the orthodox position of horse extinction in America.
Now what would one expect from a horse culture who not only use domesticated horses for hunting but also use their horses as a means of food when hunting is meagre? The horse was a food supply in hard times. To some Mongol tribes it was their only food supply.
| However, this leads on to the question of why none of the Meso-Americans (Aztecs, Incas etc) went in for any kind of horse-domestication. |
To understand this you have to understand the nature of horses. They thrive on open plains and grasslands. They do not tolerate deserts, scrubland, forests or jungles. Their digestive system is quite unique in that it only absorbs 25% of the nutrients it digests. This is why horses don't tolerate drought or famine at all. Their liquid intake is also critical; it increases significantly when grass is substituted with dry fodder as horses derive a large amount of their liquid from grass. They are also virtually useless in rocky and mountainous terrain where there are no dedicated paths; something the Spanish found to their chagrin in Central America. They are also handicapped by jungle and swamps where they are slower than men walking. The Spanish use of mules was a wise choice as they are much more robust in the legs than horses and are able to carry greater weight than horses. Horses break their legs quite easily running around on flat terrain; just look at the number of race horses that have to be put down because of this fact; and they are the 'Olympic athletes' of the species. They are also susceptible to tropical parasites; something that kept the horse out of Africa.
The Mongols were at an advantage over the plains Indians in that the terrain surrounding them was easily travelled to the East and West. The plains Indians were hemmed in, by mountains and forests to the East, West and North and desert to the Southwest.
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Mick Harper
Site Admin
In: London
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Your description of how extraordinarily (and dangerously) specialised the horse is leads one to wonder just what the "horse" is. Let us not forget that evolutionary textbooks always use the horse as an exemplar because of the (apparently) unique way the horse developed. Or rather the uniquely detailed palaeontological record of equid fossils. Could we be looking at very early domestication and subsequent palaeontological attempts to...er...preserve various paradigm.
Here's an example of what I'm talking about
| In the 1870's, the paleontologist O.C. Marsh published a description of newly discovered horse fossils from North America. At the time, very few transitional fossils were known, apart from Archeopteryx. The sequence of horse fossils that Marsh described (and that T.H. Huxley popularized) was a striking example of evolution taking place in a single lineage. Here, one could see the fossil species "Eohippus" transformed into an almost totally different-looking (and very familiar) descendent, Equus, through a series of clear intermediates. Biologists and interested laypeople were justifiably excited. Some years later, the American Museum of Natural History assembled a famous exhibit of these fossil horses, designed to show gradual evolution from "Eohippus" (now called Hyracotherium) to modern Equus. Such exhibits focussed attention on the horse family not only as evidence for evolution per se, but also specifically as a model of gradual, straight-line evolution, with Equus being the "goal" of equine evolution. This story of the horse family was soon included in all biology textbooks..http://www.talkorigins.org/faqs/horses/horse_evol.html#part1 | |
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Komorikid
In: Gold Coast, Australia
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| Could we be looking at very early domestication and subsequent palaeontological attempts to...er...preserve various paradigms? |
The only fossil evidence we have from North America is that people ate horse. And by a strange coincidence that is exactly the same evidence we find in the Eurasian Steppes.
I'd say you're on a winner.
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Komorikid
In: Gold Coast, Australia
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Another interesting fact about horses is that all horse subgenus are the same size (give or take a hand) -- the Przewalskii, Fjord, Tarpan, Mongol and American.
Equus Caballus (modern Arab) is LARGER than all of the above by a large margin and so too is Equus Germanicus (Ardennais and other heavy draught horses). This is totally against the evidence that domestic animals are always smaller than their wild ancestors.
I believe the modern Arab is a selectively bred horse as is the Ardennais. There is just no way that the American horse can be a product of the Arab.
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DPCrisp
In: Bedfordshire
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| Another interesting fact about horses is that all horse subgenus are the same size (give or take a hand) -- the Przewalskii, Fjord, Tarpan, Mongol and American. |
These are the ones said to be "most ancient". These are the ones that should be smaller than their wild ancestor-cousins.
| Equus Caballus (modern Arab) is LARGER than all of the above by a large margin and so too is Equus Germanicus (Ardennais and other heavy draught horses). This is totally against the evidence that domestic animals are always smaller than their wild ancestors. |
I think the rule of thumb is that newly-domesticated animals are smaller than their wild ancestors; or animals get smaller in the process of domestication; or domestication selects the smaller side of the family; or...
Once we get going with selective breeding within the domesticated population, we can achieve anything from the Yorkshire terrier to the St. Bernard.
| I believe the modern Arab is a selectively bred horse as is the Ardennais. There is just no way that the American horse can be a product of the Arab. |
Quite so. The American and Mongol have been left alone, the Arab and Ardennais have been tinkered with.
If you can point out where large, genetically diverse horses disappeared and smaller, genetically "coverse" {to coin a phrase} ones appeared, then you will have pointed to the actual domestication of horses.
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Mick Harper
Site Admin
In: London
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| If you can point out where large, genetically diverse horses disappeared and smaller, genetically "coverse" {to coin a phrase} ones appeared, then you will have pointed to the actual domestication of horses. |
Since the evolution of the horse is known in more detail than for any other animal, this momentous step ought to show up in the orthodox palaeontological equine record. Though of course they won't know it. Have a look, someone.
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Martin
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This assumes domesticated animals get smaller. This is not always the case. Also the 'wild' horses that exist today seem relatively small.
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Mick Harper
Site Admin
In: London
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Martin, I don't think you're allowed to say "that is not always the case" and leave it at that. What case(s) are you alluding to? Nor is it being useful to say that 'wild' horses seem relatively small. What is the meaning of the quotation marks? What other animals, pray, would constitute 'wild'?
However in amongst it all you make a significant point. All the horses that are not "owned" -- and by that I include New Forest ponies as well as Przewalskiis -- are small compared to the ones that are. Is it not fair to say there are no truly wild horses in the world today for making size comparisons? And where does the zebra come in, size-wise?
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Martin
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Guinea pigs and llamas got larger. They would select for larger or smaller size depending on their needs.
I mean wild as in non-domesticated as opposed to feral.
There are many feral horses around the world. But Przewalski's horse is the only wild horse and it is smaller than modern domesticated horses. Zebras, etc. are obviously related to the horse, but Przewalski's is related much more closely. So closely that if they are bred with a normal horse they can produce fertile offspring.
Another point regarding the Przewalski's horses; all are descended from a very small group of horses around the turn of the last century. Does this mean that these horses are to some degree inbred. Could this be connected to their reputed bad tempers, difficulty to ride, etc.? A bit like pedigree cats they can be pretty temperamental.
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Mick Harper
Site Admin
In: London
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| Guinea pigs and llamas got larger. They would select for larger or smaller size depending on their needs. |
That is not at all addressing the point. We know that it is possible to produce giganticism via selective breeding. But the question before us is: "Are the first domesticates (ie before selective breeding) always smaller than the wild version?" What is the fossil evidence for guinea pigs and llamas?
| I mean wild as in non-domesticated as opposed to feral. There are many feral horses around the world. But Przewalski's horse is the only wild horse and it is smaller than modern domesticated horses. |
You are being extremely bold in claiming that Przewalski's horse is wild rather than feral. Please list the ways you can tell the two conditions apart and show which applies to Przewalski's horse but not (for instance) to mustangs on the Great Plains.
| Zebras, etc. are obviously related to the horse, but Przewalski's is related much more closely. So closely that if they are bred with a normal horse they can produce fertile offspring. |
Sorry but you're not making yourself clear. You seem to be claiming that Przewalski's horse is more closely related to horses than are zebras, which presumably none would deny. And all horses can produce fertile offspring, can they not?
| Another point regarding the Przewalski's horses; all are descended from a very small group of horses around the turn of the last century. |
This is electrifying news. If their ancestors were wild (which they would have to be if Przewalski's horse is wild, as you claim) then who observed this "wild descent"? I find it difficult to believe there were the necessary geneticists and zoologists in Mongolia at the turn of the last century. [Is this 1800 or 1900 by the way, it's getting confusing at the turning of this century.]
| Does this mean that these horses are to some degree inbred. Could this be connected to their reputed bad tempers, difficulty to ride, etc.? A bit like pedigree cats they can be pretty temperamental. |
'Bad temper' is an interesting point re domestication. They say you cannot break a zebra -- which points to 'horses' being an entirely domesticated 'species' (including Przewalski's horse which I assume can be broken no matter how bad tempered). I cannot see how otherwise a 'breakable' gene would get into the species naturally.
I first came across this point when considering bison who, it is always confidently stated, cannot be domesticated.
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Martin
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| But the question before us is: "Are the first domesticates (ie before selective breeding) always smaller than the wild version?" |
No. Think about it. Domesticates are selectively bred, that's how they become domesticates. The selective breeding does not come after domestication- it is part of it. They can select larger or smaller examples as they see fit. What mechanism is used to explain this reduction in size hypothesis? Is there one or is it a case of they just do?
However this is not, as far as I am aware, the consensus. The fossil record is not conclusive either way, though I believe for llamas and alpaca there is evidence from DNA sampling that alpaca descends from vicuna (small to big) and llamas are descended from guanaco (big to small). If we work from that assumption the 'confusing' fossil record is a lot easier to interpret. Guinea pigs were bred for food and so large ones were selected;. there are lots of wild ones that are small.
| Please list the ways you can tell the two conditions apart and show which applies to Przewalski's horse but not (for instance) to mustangs on the Great Plains. |
The main difference is genetic. Przewalski's horse has 66 chromosomes all other horses (feral or common) have 64. Some people say the two are seperate species some subspecies. they can produce offspring, who have 65 chromosomes and are fertile, so in that sense they are subspecies. Also behaviour, Przewalski's horse are apparently virtually impossible to ride, feral horses can be trained and broken.
There were wild horses (i.e. non domesticated) in Europe up to the 18century, though it is hard to know if they were feral or not. Around 1870 Przewalski saw some wild herds in Mongolia and then described them in the academic journals. European aristocrats went nuts for them so they went back to try to catch some, but they couldn't- they would just run off if they got anywhere near them. eventually they got a few colts and fillies, about 15 and they were brought to Europe. Since then the wild horses have become extinct, the last one being seen in the sixties. (though where they live is so remote it is possible some could survive) All the Przewalski's horses today are descended from those 15. Why did they became extinct in the wild? There's a question I've not seen asked.
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Mick Harper
Site Admin
In: London
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| No. Think about it. Domesticates are selectively bred, that's how they become domesticates. The selective breeding does not come after domestication- it is part of it. They can select larger or smaller examples as they see fit. What mechanism is used to explain this reduction in size hypothesis? Is there one or is it a case of they just do? |
Well, you are mis-stating my position since I was clearly dealing only with much later attempts at stock-improvement but in any case this is not our position, it is orthodoxy's. It is a "common belief" -- I put it no stronger than that -- that domesticates are smaller than their wild progenitors. However I think you are wrong nonetheless for the following reasons:
1. We do not know how domestication comes about/came about. It is unlikely that "they can select larger or smaller examples as they see fit" since the process might well be be accidental, or at any rate haphazard and incremental.
2. However, if there is some element of choice involved then it would seem sensible to choose smaller rather than larger ones -- we are after all dealing with wild animals.
3. The palaeontological evidence, such as it is, is clearly against you. Quite decisive downsizing seems to occur over quite short a period of time. Too quick I would have thought to be the product of merely systematic size-selection. (That is why I asked for the guinea-pig and llama evidence because all the ones known to me are this character.)
4. Some other process -- for instance somehow retarding animals into a permanent juvenile state -- would appear to be necessary.
| However this is not, as far as I am aware, the consensus. The fossil record is not conclusive either way, though I believe for llamas and alpaca there is evidence from DNA sampling that alpaca descends from vicuna (small to big) and llamas are descended from guanaco (big to small). If we work from that assumption the 'confusing' fossil record is a lot easier to interpret. Guinea pigs were bred for food and so large ones were selected;. there are lots of wild ones that are small. |
If it is true that the llama is descended from the guanaco or thast the alpaca descends from the vicuna, then you have won the million pound challenge offered in THOBR to name a living species ancestral to another living species. Obviously you won't be claiming the money but you can congratulate yourself on being the only biologist to have done this.
Excellent detail about Przewalski's horses. The chromosomes seem especially important. Though I still don't accept that either they or the European horses you mentioned are ipso facto wild.
| Why did they became extinct in the wild? There's a question I've not seen asked. |
We have a large amount of stuff on "mystery extinctions" -- and we think we know the reason for them (including why the question is never asked) -- but I'm afraid it's a Treasure Hunt matter and closed. But I'm sure it'll dribble out.
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