Re: Coevolution of Honey Bees and Varroa Mites: A New Paper
Hi JB (Does that work?)
I obviously can't respond to a post of that length on a point by point basis, so I've just selected parts that might allow me to address some of the most important issues.
jbeshearse: In reality, treatments are an effective way to insure overall populations do not severely decline before the species rebounds on it's own.
Mike Bispham: There is absolutely no evidence that this is the case, and it flies in the face of fundamental evolutionary biology. It directly contradicts the clear statements, made by the authors. Bees have a natural defence mechanism - shared by all living things: die-back to resistant strains: rebuild from resistant strains. This process carries no cost in terms of diversity. Treatments frustrate that process entirely, and on an ongoing basis. Treating corrodes diversity by preventing the re-emergence of feral bees around apiaries.
jbeshearse (reply): What clear statements are you referring to? Please elaborate. Also tell me how this “flies in the face of fundamental biology.
I will elaborate. I'm going over familiar aground again, but I'm doing so to try to make a couple of points as clearly as I can. The first is about the nature and forcefulness of the principle of natural selection. The second is about the way that principle unifies many different explanations.
Here is the clear statement from the abstract:
"Coevolution by natural selection in this system has been hindered for European honey bee hosts since apicultural practices remove the mite and consequently the selective pressures required for such a process."
To those familiar with evolutionary biology or breeding sciences that statement needs no elaboration. Its a straightforward consequence of the general principle of natural selection for the fittests strains.
This is very very simple, but a clear understanding is essential!
Nature tends to breed more from the stongest individuals than from the weak. Since qualities are inherited, this passes more of the better qualities to the next generation than the less-good qualities.
There are many different mechanisms that press toward this outcome, perhaps the most obvious being that the weakest (most unfit) die before they are able to mate. The strongest reproduce the most, the weakest reproduce not at all, the middling ones reproduce in middling numbers.
Another powerful mechanism; the strongest males tend to win mating competitons. Again this contributes to each new generation tending to be made from genes supplied by the strongest parents. In these and other ways, generation after generation, weakness and vulnerabilities are winnowed out, on an ongoing basis.
Can you see how neat that is? If not, read it again, and think about it some more. When you feel some kind of shock at the sheer elegance of what goes on, a billion times a day, always, and how that is able to maintain life itself, please, hold on to that and don't let go! Come back to it whenever you feel wobbly! That is the underlying, fundamental principle of the organic sciences! Nothing less. You cannot argue with it, or twist it. It is simply a (rough) description of a fundamental reality.
In animal husbandry this process is copied. Now, instead of natural selection, artificial selection is used. The husbandryman chooses those parents that s/he thinks will make the best offspring, and uses those, and only those, as breeding pairs. ('Pairs' is misleading since often one male will sire many females - but they're all 'pairs')
The art of raising good breeding pairs is fundamental to the success or failure of the husbandry. Allowing weakly, slow-growing, or disease-prone stock to enter the breeding pool carries the probablity that those weakness will be reproduced in the offspring. And so any animal showing any deficiency is quickly removed as a contender for future breeding stock. Only the very best are allowed through.
Do you see how nature has been copied? How animal husbandry and natural selection are using the very same means to maintain health and vitality, and quickly take out weakness?
This is the golden rule of husbandry. Both nature and husbandry work with the fact that traits are heritable, that mother and father pass down parts of their make-up to their children. It isn't precise nor predictable in individual cases - but as things average out, it works.
Now lets marry to the above the following:
"Breeding is by no means a human invention. Nature, which in millions of years
has bought forth this immense diversity of wonderfully adapted creatures, is the
greatest breeder. It is from her that the present day breeder learnt how it must
be done, excessive production and then ruthless selection, permitting only the
most suitable to survive and eliminating the inferior." Friedrich Ruttner,
Breeding Techniques and Selection for Breeding of the Honeybee, pg 45
Now: Can you see how what Ruttner, one of the all-time great bee breeders, says is in complete agreement with my outline? Can you point to any strains or contradictions between what I've said and what he's saying?
I've sketched the evolutionary biology that underpins the statement made by the authors, and outlined the most basic animal-raising principle, and shown how Ruttner works from the same understanding. And there is complete concordance between them all. Complete agreement between scientists, animal husbandry principles, beekeeper. That concordance is that all are united by an understanding of this most basic principle of organic life - Natural Selection for the Fittest Strains.
There is complete concordance too between this web of interrelated understanding and the medieval dictum 'Put Best to Best.'
Can you see this? Can you see: this is the music of animal science, the tune that life dances to?
Stay with this. This is Golden.
Now: This process is - essential - to the maintainance of health. There is, we've heard, a sort of constant 'arms race' between every host and their many predators. The predators are constantly seeking to gain more food (for that's what its all about - everything needs food to live at all), the hosts must equally constantly seek to prevent that. The two populations therefore are locked in a sort of race, each seeking the upper hand. Constantly. And each uses the same tool, adaptation, evolution by natural selection.
And so... if you stop evolution in the host, you allow the predator to gain an advantage. In each generation.
Selection, by nature or by husbandryman, is then essential to prevent the predators gaining advantage.
Selection, by nature or husbandryman, is what allows - or creates - the necessary adaptation
So (last part): by logic: what happens when we prevent - or seriously inhibit - adaptation in the host by frustrating selection?
Something - anything - is essential. We remove it. What happens?
What does treatment do? It removes the natural selection that would otherwise occur. What happens when we stop the selection processes?
I can't do more than this. You have to be able to understand the dance, to hear the music, apply the understanding with simple logic. Then it all makes perfect sense, and you breath a sigh of relief, and sit in wonder at the magnificent elegance of nature's wonderful basic health-maintenance mechanism.
And the questions you ask me answer themselves, easily and naturally.
I've said far too much: the thing is beautifully simple and elegant. And what you have to do, as a husbandryman, is obey the dictum. Put Best to Best. Only.
Is that so hard?
If you keep looking until that is all properly clear and firm, you will be able to see that your next statement simply is not in accordance with the web of understanding that flows from the simple fact of inherited traits. I'll show you why:
jbeshearse (reply): We are not treating the bees for varroa, we are poisoning varroa and to a degree bees. This in no way removes the effects of fundamental evolutionary biology. Frustrate it yes, prevent it, no. As humans we interfere in the process, but we cannot overcome it. A die off is the last line of defense. Fundamental evolution demands that defenses that do not result in death will be favored over those that do result in death.
First, 'a die off' is not the last line of defence - the death of the weakest (without reproducing) is an important part of the _first_ line of defence!
Second: back to the paper: "Coevolution by natural selection in this system has been hindered for European honey bee hosts since apicultural practices remove the mite and consequently the selective pressures required for such a process."
Don't misread that 'hindered' - it doesn't signal a time issue as you think. Note the second part; the selective pressure is removed. Without selective pressure there will be no adaptation. Ever. Without sdelective 'pressure' on a population there is nothing to drive any change, nothing to adapt to.
jbeshearse (reply): It is never easy to make a convincing case to entrenched positions. I never said that evolutionary biology is going wrong. I don’t even know where that came from. What I did say was that treatments are only a stopgap measure until natural selection takes over.
The 'entrenched position' is the inarguable fundamental principle at the root of evolutionary biology. And what that tells us is: your 'stopgap measure' prevents natural selection from occurring. Natural selection, where it is given free rein works just fine. Where treatments are made it cannot work - and there is no adaptation. And that is the crux of the problem. That's why treatments are described as 'addictive'. The more you treat the more you need to treat. (Actually its worse that that: treating only a bit creates a downward spiral as resistance is progressively lost). Where treatments are removed, and husbandry is done properly, things work fine.
Can you see now how all the evidence fits together, and is united with the great web of understanding that is founded upon the recognition of inherited traits, and natural selection of the fittest?
Again: find that music. Dead animals don't reproduce; the strongest reproduce most, health is passed on down.... this _process_ is essential to life. Understanding it essential to successful husbandry.
You cannot treat and expect any adaptation to occur. Indeed, if you start treating adapted bees they will, over the course of a few generations, adapt to the new environment, and lose their resistance.
Last edited by mike bispham; 09-26-2012 at 08:12 AM.
The race isn't always to the swift, nor the fight to the strong, but that's the way to bet