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using a species to increase subspecies numbers hybridisation!

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Offline Clive

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« on: November 06, 2007, 22:37 PM »
Hello all,

If I may borrow tp's  :technodevil: for a moment.... political and environmental situations not included...

In the case of the Cantabrian brown bear and its possible sub species status... why, when numbers are so reduced, is it that breeding programs with the closest relative (European brown bear) are not considered. Surely the survival of the species is paramount? Not the sub species.

What huge difference is there in the diet, habitat and general behaviour of ursos arctos parda and ursos arctos that prevents a hybrid breeding programme?

Surely the resulting hybrids will be better suited to life in our modern world as they have survived thus far...

Same question applies to pardel lynx and lynx lynx...

Why is protecting the subspecies so important when in many occasions the genetic pool has been lost in order to procure a future for the subspecies in question?


(the text above is not necessarily the opinion of the author........The questions are merely hypothetical)


Clive
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Offline nick

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« Reply #1 on: November 06, 2007, 22:53 PM »
Cantabrian brown bear may or may not be a subspecies...but

lynx pardinus and lynx lynx...are seperate species. No debate there. Separated a million years ago or so...

I wrote this several years back
http://www.iberianature.com/material/lynxeagle.html

Whtever the case,no longer sure about the phrase "did not originate in Iberia's Mediterranean forests. "
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Offline Clive

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« Reply #2 on: November 06, 2007, 23:09 PM »
I am not disputing the species distinction in either bear or lynx. That is for the scientists to decide.....

What I am asking is.. Is it ethically wrong to utilise cross breeding within close species groups in order to enlarge a gene pool and thus save the species (all be it slightly impure)

For example if a male lynx lynx inseminated a female pardel lynx and the resulting cubs were bred with pure pardel lynx then the "grand cubs" would only be a quarter lynx lynx (not forgetting about genetic throwbacks)

I wonder if anyone would be able to tell the bloodline of these hybrids by looking at their behaviour in the dehesas of cardeña...

Would the resulting animals be any different at all from a "pure" pardel lynx?

Clive
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Roxanne

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« Reply #3 on: November 06, 2007, 23:44 PM »
If the lynx are two different species then surely you couldn't cross-breed them? Not in the ordinary way; not without manipulating things under a microscope. As I understand it, the definition of a species is that it can't breed with other species.

Jill (who took over from Roxanne, earlier on in the evening, and can't be bothered to log out and log in again).

Offline Clive

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« Reply #4 on: November 07, 2007, 09:11 AM »
Hey Jill (and Roxanne)

Well I would think if things like ligers and tigons exists and also mules and hybrid wolf dogs I think that to cross breed to close species of lynx and or bear would be just as simple...

But like I said, my question is not whether the scientists agree or not about a species/subspecies or whether it is possible or not to create a hybrid..

I am trying to get to the bottom of whether it is ethical to do this and also what difference would it make to the general balance of nature in a lynx or bear area if hybrids were there...

Species are going extinct every day and it seems to me that the major problems occur when a gap is left after a species is gone (Example Asian vulture /diclophenac to see catastrophic events on balance of nature after a huge (90%) population crash)..

Also see Pyrenean Ibex extinction as an example where careful breeding using other caprine bloodlines could have added a new dimension to the protection programme that ultimately failed because they simply ran out of "pure" adults

instead of failing and seeing a species go extinct why not replace it with the nearest closest relative possible? That would be a hybrid of the closest species...

Do we humans have an obsession about purity of race and if we can't attain that then the animal is worthless? After all humans have been selectively breeding many types of lifeform for many many years...

food for thought?

Clive
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Offline lisa

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« Reply #5 on: November 07, 2007, 09:35 AM »
Well. In the case of the Cantabrian brown bear, they're doing just about well enough in the wild to not have to consider cross-breeding with other bears at the moment but I'm sure that has been considered. The whole point of their conservation is that they are different and should not be allowed to die out. In the Pyrenees bears have been introduced from eastern Europe because it was too late for the survival of the indigenous bears so the authorities used the last resort of importing other bears.
It all goes to prove that though international scientific opinion is divided on the sub-species status of Spain's bears, Spanish experts are not so divided.  

In the early part of the last century, the taxonomist Cabrera recognised the Cantabrian brown bear as being a distinct sub-species through the darker colouring of its extremities and the yellow colouring of the tips of its fur. Clive, have you read this? (Going to revise it slightly later) We'll see if DNA analysis doesn't come up with something soon  >:D
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Offline Clive

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« Reply #6 on: November 07, 2007, 09:40 AM »
I just can't keep you guys off the is it or isn't it subject....

I would agree that in the Cantabrian brown bear scenario there are enough animals to create a stable genetic pool so any cross-breeding would not be needed as yet.

Like I have said... I want to discuss things other than taxonomy.....


Clive
« Last Edit: November 07, 2007, 09:47 AM by Wildside »
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Offline Technopat

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« Reply #7 on: November 07, 2007, 14:32 PM »
Greetings All,
Right!
First of all, must point out what I have said on numerous occasions: for every six experts who agree on one basic issue, you’ll find another half-dozen who will disagree. In whatever field of study, and however supposedly scientific said study claims to be (quantum mechanics has http://en.wikipedia.org/wiki/Observer_effect and/or the http://en.wikipedia.org/wiki/Uncertainty_principle; and we all know the state of the art re. the origin of the species, etc.).

It is notorious that all the students attending a certain faculty during a certain period will agree on certain basics. Likewise a group of experts working together in a group. Discordant voices are either forced out or forced to keep quiet. Expressions such as “All the experts agree ...” are weasly and directly untrue if taken out of context: “All the experts in the working group agreed ...” The reasons for such discrepancy are irrelevant. They can be justified using the “scientific method” and they can be equally demonstrated to be false, or, at best, incomplete, using another, equally valid, “scientific method”.

And then of course, to the group of experts, we also have to add the “purists”. Both in the sciences and the arts, these sprout up like whatchamallems and blur the issues even further. In music, jazz purists insist that Duke Ellington’s Orchestra did not play jazz, because they insist that jazz by definition is improvisation and cannot therefore be orchestrated; classical purists have delighted in criticising just about every composer/virtuoso that has ever emerged, and so on. But I digress ...

Having checked out the “species problem” at Wikipedia http://en.wikipedia.org/wiki/Species_Problem and from which I quote liberally hereinafter, the working definition, albeit not a very scientific one, of species is that of organisms able to interbreed with each other and produce fertile offspring. Leaving aside the issue of asexual vs. sexual reproduction, such a sweeping definition is so fraught with difficulties and exceptions as to become scientifically meaningless.

An example given by Wikipedia is that of Great Danes and Chihuahuas. In nature it is clear that there would be no possibility of these two members of the same species interbreeding. Artisem is another matter. And there is no probably no doubt that the ensuing hybrid would evolve in whichever direction the dominant genes were to take it. Surely all animals are hybrids. The human being certainly is. Natural selection rules OK.

Darwin himself – pre-DNA days – said “I look at the term species as one arbitrarily given for the sake of convenience to a set of individuals closely resembling each other .... it does not essentially differ from the term variety, which is given to less distinct and more fluxtuating forms.” And I think his statement is equally valid even in these DNA-loving days. It is merely a term. A term that is relative to our current knowledge of a matter, and which will certainly be modified or directly ditched as science progresses. Or rather, as the mainstream scientific body of the day accepts a new theory.

Over and out (for the moment ...)
Technopat
Technopat's disclaimer: If this posting seems over the top and/or gets your goat (Sp. anyone?), please accept my apologies and don't take it personally - it's just my instinctive tendency to put my foot in it whenever/wherever possible. See also:
http://www.iberianatureforum.com/index.php/topic,266

Offline Clive

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« Reply #8 on: November 07, 2007, 15:41 PM »
Ok, so it looks like I am going to have to get tough in order to stop this constant bleating about species definition in this topic... Can no one see the direction of my posts at all?  ::)

As a hypothetical test area lets please forget about disagreements about classification and taxonomy...

Fact. (in my opinion) There are too many griffon vultures in Spain that are undergoing hunger stress due to laws on disposal of carcasses

Fact. the Asian vultures have been decimated by the drug diclophenac http://www.birdlife.org/action/science/species/asia_vulture_crisis/diclofenac.html

Quote
Diclofenac, a Non-Steroidal Anti-Inflammatory Drug (NSAID), has been found to cause gout and renal failure in vultures of the Gyps genus. In India, where Diclofenac was in widespread veterinary use, three Gyps species, formerly of Least Concern, have been pushed to Critically Endangered status, losing over 99 percent of their populations in just over a decade.

At the same time as the vulture decline in India, nature has filled the void by a population explosion of feral dogs and other scavengers and this huge imbalance has created a very bad situation.. (remember all the food that the vultures used to eat is now still there and being eaten by other scavengers of left rotting in the fields adding to disease problems)...

financially millions has been spent on discovering what the problem was and also grants and huge funds are being spent on captive breeding schemes to ensure the survival of them....(White-rumped (Gyps bengalensis), Indian (Gyps indicus) and Slender-billed Vultures (Gyps tenuirostris))

Now then, here we go for one possible solution....

Fact.
The griffon vultures of Spain eat a similar diet as the Indian ones and do pretty much exactly the same job as the Indian ones that are now so in danger of extinction...

Solution? When griffons(usually juveniles I am told) migrate and are caught for any reason IE they are sick and need help or are thin and just need feeding or they are captured for ringing purposes...

Why not transport them to India to replace the lost Indian vultures?

What ethical reason would there be against it... The breeding programs of the endemics will take decades or more and by then the balance will have changed so much that maybe there will be no place for the newly released birds...

The Idea I propose is faster and solves to problems in one go... Too many Gyps in Spain and not enough in India!

Clive

PS I don't want to talk about diclophenac or Species taxonomy!  ;D
PPS I am also not talking about introducing alien species into environments. This is purely about introducing a species so similar to the original that little or no negative affects will be noted....

« Last Edit: November 07, 2007, 15:56 PM by Wildside »
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Offline Jill

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« Reply #9 on: November 07, 2007, 18:30 PM »
Hullo Clive

Okay, now I can see where you're coming from.

I think that mankind, as a general rule, has a tendency not to want to "play god". The exceptions to the rule are the scientists, of course - they just love interfering - but the rest of us are afraid of upsetting the balance.

Yes, we are obsessed by the idea of purity. I think that it's because we consider that a man-made animal is not really wild. And we cherish true wildness. Hence, watching lions in a reserve is exciting, but not a patch, in my opinion, on watching badgers who are living out their lives in the Real Wild. By the same token, we also have our doubts about Wild Cats. "Is it really a wild cat," we ask ourselves, "Or is it just a wildcat that has crossed with a tame tabby?" Pure = Real.
Given the increasing size of the human population and our increasing impact on wildlife, it may very well be that ours is the last generation to have the privilege of seeing truly wild animals; our grandchildren may only know them as the inhabitants of Nature Reserves and such-like.

I seem to be digressing here.

On the whole, I think that we are justified in worrying about the far reaching effects of our intervention in Nature, and until very recently I've had a "don't touch it" attitude to such things. However, I have now come to the conclusion that mankind MUST now interfere with Nature. We've trashed Nature, and we've trashed it/her so badly that the wounds won't heal without our intervention. I have now reached the stage where I believe that the sort of thing that you are suggesting (re. the vultures) is the only sane course of action. Because, as you intimate, the only other course - that of sitting back and watching to see whether the natural world can recover - is going to end in disaster. No intervention will mean no more vultures in India.

Nevertheless, I think we / environmentalists / scientists need to tread very, very carefully because, as I say, our interventions will have far reaching consequences.

The most obvious consequence is that, assuming that it were possible to cross breed two distinct species, the result would be the annihilation of the endangered species. In the case of the Indian vultures this may be the lesser of two evils. Aside from anything else, Indian society evidently needs vultures in order to inhibit an increase in the numbers of semi-wild dogs. In the case of the European and Spanish bears... well, I'll let Lisa comment on that one! On the whole I would say that it is justifiable only where the endangered species seems almost certain to become extinct without our intervention and manipulation.

Having dealt with the ethics, we do need to return to the practicalities and realities. In the case of the Indian vultures I don't believe that the introduction of Griffons would solve the problem. On the contrary.
As I have said, so far as I am aware, it is not possible to cross-breed two distinct species of animal. Dogs are breeds, not species, so they don't count. Yes, you are quite right, of course, - you can cross a horse with a donkey. And False-killer whales have been known to breed with dolphins. (Albeit only in captivity. In the wild, False-killer whales kill dolphins.) These, and other differing species have interbred, BUT the progeny are invariably infertile - or so I have always understood.

(Plants are a different matter.)

If the Griffon vultures were to be introduced to India then, far from interbreeding, the two different species would probably compete. If there is an absolute abundance of resources then both might survive. If not, the bigger and stronger would be the winner. If Griffs are smaller than the local guys, but the local guys are few in number, then the species might co-exist and, together, would help to reduce the numbers of dogs. Then, once the numbers of locals increased they might wipe out the incomers (simply by depriving them of access to the food, or to nesting sites.)

Looking on the bright side (which I generally don't...), it is possible that the two species would each fill a slightly separate niche. Perhaps they enjoy slightly different habitats? Then they might co-exist merrily, and live happily ever after, like in the fairy stories...

Examples of a situation where introduced species have wiped out an indigenous one are numerous, I am sure. But the only one I can think of, on the spur of the moment, is the (inadvertent?) introduction of foreign freshwater crayfish to British streams. They are said to have decimated the local population of smaller crayfish.
Likewise, the release of mink from mink farms, by well-meaning but ill-informed activists, has led to a drastic decline in native British wildlife such as... water voles, IF I remember rightly... (Or was it otters?) Anyway, you can see what I'm getting at.

In summary, then:- Nice idea, Clive, and I'm with you on the ethics. But probably not workable - unless somebody can prove that Griffons and Indian vultures can reproduce, creating viable, fertile offspring.

Time for a drink, after that little lot.
Bung-ho!

Your pessimistic correspondent
Jill

P.S. Of course, if the Indian vultures do die out, then would be an excellent moment to introduce an alternative species of vulture.

Offline Clive

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« Reply #10 on: November 07, 2007, 20:04 PM »
Thanks Jill for your thoughts... :)

Just to clarify my point on the vultures being taken from Spain... I did not mean it to sound as if the Spanish griffons would be introduced in order to cross breed with the Indian vultures. They would be there simply to control the amount of carrion rotting in the ground and to help eat the food that the other scavengers would get therefore helping to retain a modicum of scavenger species balance...

Right now in Iberia we have probably over 20,000 griffons, a couple of hundred black vulture, Egyptians seem to be reducing ias well (a few hundred).... Bearded vulture numbers?

We could reduce the stress on the food supply here in Iberia and help the threatened black, Egyptian and bearded by removing some griffons to a place where they are needed...

As the griffons removed to India start to increase and breed in their own right they too may possibly need to have numbers controlled so as the breeding programmed birds of the endangered three species have room to expand...(In this I am suggesting controlled culling)

All that would be left if this hypothetical plan succeeded is 4 stable populations gyps species instead of 3....

Your last comment Jill I find interesting.. You see I would implement my plan as soon as possible and not wait for the three indian species to die out...

Still staying off the subject of species taxonomy and also I am not talking about introduction of invasive species ... :)



Clive
« Last Edit: November 07, 2007, 20:11 PM by Wildside »
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Offline Jill

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« Reply #11 on: November 07, 2007, 21:32 PM »
I wonder why the numbers of black, Egyptian and bearded vultures are reducing whilst the Griffons are apparently doing too well? If it's simply a case of lack of carrion, why aren't they all reducing? Could it be that the Griffons are driving the others out?

I like your idea, Clive. And if one could be sure that the Griffons would not compete directly with the natives, and so INCREASE the pressure on their populations, it would be a good thing.

But how can we know, in advance, which introductions will be benign, or helpful, and which will be "invasive species"?

Offline lisa

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« Reply #12 on: November 07, 2007, 21:46 PM »
Apologies for banging on there Clive, but it did seem relevant at the time.
It's going to take me a while to ponder the ethics of this and the possible adverse effects on both of the ecosystems involved. As the supposedly most intelligent species on earth, we've made a bit of a mess of things so far and I agree with Jill in that we need to put things right but these things do tend to snowball.
For now I'll just add that removing Griffons would not help the Bearded vultures as the latter need the former in the food chain.
And what about disease immunity?
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