That's what I would expect, with or without 'tolerance genetics' etc.
Swarms have very few varroa, they've left them behind!
Hives which have swarmed have a prolonged brood break inhibiting the reproduction of varroa.
However you look at this, if both swarms and mother colony survive and thrive multiyear from then on there is clearly no varroa problem. If both swarm every year there is a swarminess problem. I don't see swarminess, but I run unlimited broodnests. Possibly the practice of queen cell removal and restricted brood nests is making it harder for some bees (those more highly reliant on swarming) to manage their mites.
There is Survivorship Bias here (Google it); you could take ten hives, half die, but they all have exactly the same genetics,
No two colonies have exactly the same genetics. Like people, each queen is an INDIVIDUAL with a unique gene set. So you need to rethink all that runs on top of this incorrect assumption.
the half that survived were just lucky... unless one can pinpoint something(s) that enabled them to survive, and yet the survivors are given such names as survivor stock when being lucky is equally a valid explanation.
(Forgetting for a moment what I just said):
"You can't be sure that the strongest will always win, but that's the way to bet"
This comes from the context of evolution, natural selection and breeding. We don't arrive at having a million species, a thousand breeds of dogs, all domestic animals and fruit and veg by luck. We get them because nature/ the breeder favours the strong, the fit.
Nature's method is to over-produce (offspring that are INDIVIDUALS), then ruthlessly select the best (on a rough and ready, average, all else being equal) basis: AND MAKE EACH NEW GENERATION FROM THOSE.
You won't get a grip on the mechanisms that give rise to health in populations, on the predator-prey relationship, until you can see the way the machine works.
Anything that inhibits the reproduction of varroa will increase tolerance (lengthen the lifespan of the hive/colony), to date this is;
1. [... ] 6
What you are missing is the difference that exists within those mechanisms, the nuances; plus unknown mechanisms, plus IMPORTANTLY the fact that they don't manifest one to the exclusion of all others. They manifest IN COMBINATIONS.
An analogy: Your are looking at the notes of a scale, and saying: 'this one doesn't make make music, this on edoesn't make music, none of them make music' The mistake of course is that more than one at a time is needed. And that there are lots of different tunes.
This makes for a much more complex picture. It is, furthermore, one that is continually changing, as the predator-prey arms race endlessly unfolds.
You seem to be determined to deny the possibility of something that is both clear in the literature and the personal experience of thousands of beeks, by claiming the science is inadequate to an explanation. It isn't. The science of the mechanisms is not complete, and probably never will be - the material is too complex due to those nuances and combinations I've just spoken of.
But the match of evolutionary theory to evidence is perfect and complete.
Evolutionary theory explains how populations react to pressures in their environments, how health is recovered and maintained, why evolutionary reaction _must_ occur continuously in order for health to be maintained.
In short, you can't see the wood for the trees, any you aren't even cognizant of the fact that the trees grow, change, are born, live and die.
Anyone else think of other factors backed up by science? I have mentioned small cells, that could require a Thread of it's own!
Yep. All the above. Forget all you know about the trees (mechanisms) and go and learn about the nature of the woods.
If for no other reason that that is the topic of this thread, and you are persistent dragging it off elsewhere. If you are that interested in mechanisms, perhaps starting a mechanisms thread would be a good idea. This paper would provide you with a good start:
Honey bee survival mechanisms against the parasite Varroa destructor: a systematic review of phenotypic and genomic research efforts.
From the abstract:
"An alternative approach to chemical treatments is to selectively enhance heritable honey bee traits of resistance or tolerance to the mite through breeding programs, or select for naturally surviving untreated colonies. "
And further down:
"....natural selection has yielded honey bee populations in Europe, North America, South America and Africa that survive varroa without parasite management (
Locke, 2016;
Fig. 1A). The underlying mechanisms are not all well understood, and seem to vary between different naturally selected populations despite experiencing similar selection pressures "
https://www.sciencedirect.com/science/article/pii/S002075192030093X
This thread please note is about natural selection and the honeybee, and the perfect match between evidence and evolutionary theory found there.
None of the above has really anything to do with so called local adaption, except virus resistance (which to date is theoretical).
It's not theoretical. It's evidence-based, science-based and the lived reality of tens of thousands of beekeepers. And you are in denial about that, for some reason or another.
Suggestion: look up the Red Queen Hypothesis and come back and give us an account of it. That will show us how much you can, and are willing to, engage with the material, with the topic of the thread.