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Ishmael
In: Toronto
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| Mick Harper wrote: | | 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. |
I thought I claimed that prize when I identified the grizzly bear as the ancestor to the polar bear. That's the current orthodox claim. Look it up.
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Mick Harper
Site Admin
In: London
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Didn't you get the cheque? It was certainly cashed so I expect a Canadian postie half-inched it. Or is Natalie walking round in a suddenly acquired mink coat?
I'm afraid I can't send another one because, late breaking news, somebody has just claimed that the polar bear is the ancestor to the grizzly bear not the other way about. No, wait, something's just coming through the wires...a cub has been born in Medicine Hat Zoo to a grizzly mother and a polar bear father (by artificial insemination admittedly but they're still now officially one species). No, 'ang about, somebody else is claiming they're both evolved from the European Brown Bear...oh no, a telegram from the British Ursine Society has just arrived...
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Martin
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| 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 |
We don't know much about domestication of large mammals because all the potential candidates were discovered and domesticated long ago - all by 2500BC. Of course the process was probably haphazard, however if the domesticators are not selecting for a trait they deem desirable, what were they doing? However there are recent domesticates, like the chinchilla. I don't know much about their wild ancestors
| 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. |
Only if the size of the animal is a problem. There are some very aggressive and unpleasant small animals as well as docile large 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.) |
I am not saying they always get bigger, just that they don't always get smaller. The evidence is very poor for domestication in general so it is very hard to say what it proves either way. Luckily we have the genetic evidence as well.
Animals can be selectively bred and change appearance quite rapidly; was it not possible then?
| 4. Some other process -- for instance somehow retarding animals into a permanent juvenile state -- would appear to be necessary. |
Possibly, though I don't see why.
Here are some other living species ancestral to other living species
sheep-mouflon
goat- bezoar goat
pig- wild boar
donkey- African wild ass
domestic reindeer- reindeer
Bali cattle-banteng
Mithan-Guar
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Ishmael
In: Toronto
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| Mick Harper wrote: | | ...late breaking news, somebody has just claimed that the polar bear is the ancestor to the grizzly bear not the other way about. No, wait, something's just coming through the wires...a cub has been born in Medicine Hat Zoo to a grizzly mother and a polar bear father (by artificial insemination admittedly but they're still now officially one species). No, 'ang about, somebody else is claiming they're both evolved from the European Brown Bear...oh no, a telegram from the British Ursine Society has just arrived... |
Yes. When I first raised the subject, I suggested that the Grizzly ancestry of the Polar Bear had achieved consensus among those interested only because so few were interested. If the ancestry of the Polar Bear were suddenly judged of great importance, I am certain that the matter would suddenly re-open -- and the quest for a long-extinct common ancestor would begin.
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Mick Harper
Site Admin
In: London
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4. Some other process -- for instance somehow retarding animals into a permanent juvenile state -- would appear to be necessary.
Possibly, though I don't see why. |
Just a nifty thought. It is well-known that pets -- dogs and cats -- are the way they are because they spend their entire lives supposing they are puppies/kittens and we are their parents, so by extension domesticated animals are sort of adolescents.
It is always accepted that domestication took place zillions of years ago but nobody ever asks why we don't do it today. After all, what better way for tourists to travel round the Serenghetti than on zebra-back. The answer is we don't know how. So the Ancients must have had some specific technique....and it's about time we (I suppose that'll mean us here at the AEL) discovered how they did it.
Your list of species is all concerned with domesticates. You have to name two wild species to claim the prize (not that I accept any of your examples as being other than "conjectural"). What's a mithan-guar?
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Martin
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| It is always accepted that domestication took place zillions of years ago but nobody ever asks why we don't do it today. |
The answer would seem fairly obvious- there are no large wild mammals that could be domesticated today that have not already been domesticated.
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Ishmael
In: Toronto
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Why does biological life appear to evolve through recurrent phases of gigantism?
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Mick Harper
Site Admin
In: London
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| Why does biological life appear to evolve through recurrent phases of gigantism? |
I'll give the orthodox answer, at least I assume it's the orthodox answer since it is just sitting here in my brain, left over from God-knows-what.
1. Everything is normal size.
2. Some new species arises which is more successful than its peers.
3. New species tends to kill off old species.
4. New species acquires monopolistic status.
5. Therefore only competition comes intra-species.
6. So bigger tends to kill off smaller.
7. So survivors tend to get bigger and bigger.
8. Until size itself becomes a disadvantage.
9. Hence smaller animals tend to succeed.
10 Everything is normal size (though what is "normal" might be open to question, cf Wireloop's small-median-big).
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Mick Harper
Site Admin
In: London
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Wandering around Longleat Safari Park the other day, got me wondering about top-o'-the-line predators. Basically, lions have got nothing to worry about except other lions. Now of course most lion vs lion killings occurs when new male lions kill lion cubs when they take over a pride but why aren't male lions even bigger than they are? After all, they don't need to hunt themselves (the lionesses do all that), all they've got to do is kill other male lions to get access to the lionesses. Answer: well, they've got to hunt for themselves in the period between growing up and competing for a lioness. Presumably giganticism is always kept in check by something or other practical.
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Ishmael
In: Toronto
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Mick Harper wrote: | I'll give the orthodox answer, at least I assume it's the orthodox answer since it is just sitting here in my brain, left over from God-knows-what. |
I've been reading a fascinating book written in 1917. It's called Growth and Form. I saw a woman reading it on the train and, looking for an angle to flirt with her, I asked her about the book. She showed me a picture from within its pages that blew my mind.
If you've not read this book, it's worth reading. I was drawn to it because of its discussion of Phi and how nature builds numbers such as that into its structures. I'm only halfway through.
Nevertheless, the author shows that there are physical forces that influence size (in fact, he argues that all growth and bodily forms are largely determined by physical forces). This aspect of biology is completely ignored by Darwinists.
Can you guess where I am going?
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DPCrisp
In: Bedfordshire
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| 7. So survivors tend to get bigger and bigger. |
In case it's relevant: did you know that there is a very clear correlation between the sizes of birds and the sizes of their eggs... but that the kiwi is 'out of place' by miles? Their eggs are almost as big as they are.
But if you plot the sizes of the eggs in its familiy (moa?), the kiwi's egg is on a par. It's as if the kiwi shrunk but its egg did not: presumably because the hatchling is then almost fully grown. Though what competitive advantage a kiwi needs, I don't know offhand.
Or vice versa: the birds grew {If it's moas I'm thinking of, they were giants.}, but the eggs didn't. Easier for a big parent to protect small young? (I doubt it.) Pop 'em out quick coz there's plenty of fuel for rapid growth? (Dinosaur eggs are all much of a muchness, no matter how big the adults, I think.) What's the rush? Whatever the situation was, it seems to have reversed.
And let's not get carried away thinking animals pop out their young at such-n-such a rate because helps (or hinders) them(selves) in any way at all...
| After all, they don't need to hunt themselves (the lionesses do all that) |
I think they've found that lions hunt much more than they used to tell us, particularly at night.
Hyenas are definitely something to worry about: you might ask again why not bigger? But do they have to be any bigger than big enough to cope?
Are cheetahs at the top of the food chain, too? They play a very different game.
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| Can you guess where I am going? |
On the train? To and from work. Are you going to get Phi times bigger... and then Phi times smaller?
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DPCrisp
In: Bedfordshire
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| Guinea pigs and llamas got larger. They would select for larger or smaller size depending on their needs. |
The point about the size of the llama is obscured by jumping ahead to selective breeding. The guinea pig might suggest something else, though: rather than first domesticates being smaller, perhaps first domesticates are nearer to human size than their wild cousins: big animals get smaller, small animals get bigger; first domesticates are more manageable. Maybe.
Rabbits are smaller than hares...
If the animal is small enough, there is no particular advantage or disadvantage in its size...
Guinea pigs might have been domesticated in "modern" times...
Maybe the bigger individuals tend to get eaten first anyway, leaving the smaller individuals to produce the first generation in captivity, even with small animals...
I dunno...
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DPCrisp
In: Bedfordshire
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| 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. |
A conundrum for palaeohippology is that horses are more genetically diverse than their wild ancestors, contrary to the observation on other domesticates. And contrary to plain common sense, we might add, since domesticates represent a limited branch or branches of the wild family.
They attempt to explain this by a convoluted account of multiple domestications of the horse, somehow mixed together... but the problem goes away if they realise that what they took to be wild ancestors and primitive breeds are all domesticated horses.
This means the horse was domesticated MUCH earlier than they think, that's all. And why not? (What they present as the earliest signs of domestication -- some bit wear and a possible corral -- strike me as rather advanced.)
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DPCrisp
In: Bedfordshire
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| It is well-known that pets -- dogs and cats -- are the way they are because they spend their entire lives supposing they are puppies/kittens and we are their parents, so by extension domesticated animals are sort of adolescents. |
It's hard to say what is domestic about a domestic animal, except that they live and die on our schedule. (And that in itself might mean "never learning to stand on their own four feet".)
It includes being allowed or encouraged to breed. At least, it does now. As for selective breeding, surely you have to have control of breeding before you can even think about being selective.
By definition, they were keeping wild animals... and slaughtering them for food when needed. (Meat isn't perishable until it's dead.) {We can forget about wool and milk: that's an intimate relationship that suggests they are already domesticated.} When it comes to breeding, the first question is which ones live long enough to be able to breed? Surely, the smallest, most docile individuals. {People eat crocodiles, but they don't keep them hanging around. The question of selecting the best ones and coming up with a domestic breed that we can keep safely does not arise.}
There's no need to suppose they selected individuals for breeding if the ones they left alive selected themselves, as it were.
Once breeding is taking place in controlled conditions and some of the offspring get to repeat the cycle next season, we have domestication.
And then what? Do you say to yourself "now I've seen what they've done, I'll try to capture some wild boar and rear them for myself"; or do you say "this guy has pigs for sale, for eating or for breeding"?
Domestication is the matter of which animals have actually, historically found a market and been incorporated into our lifestyle.
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Ishmael
In: Toronto
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| DPCrisp wrote: | | If the animal is small enough, there is no particular advantage or disadvantage in its size... |
Unfortunately Dan, what was a simple and elegant hypothesis has now degenerated into what looks increasingly like special pleading.
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