> The last figure I heard was 1% inbreeding (a Wright calculation for those interested) resulted in a 1% lower milk production.  I have yet to hear any evidence that suggests to me we are suffering a bit from inbreeding suppression in honey bees. 

This is what I am saying. Basically, you have two ways of determining if there is loss of diversity: 1) inbreeding effects and 2) genomic analysis. 

There are numerous examples of very restricted island populations of honey bees, which show no signs of inbreeding depression. Now, the island effect could account for the unusual African bees of Puerto Rico. That is not to say they are overly inbred, but if a trait was advantageous in some profound way it could prevail in an isolated population, conferring benefit. 

The genomic analysis is a bit of conundrum. What you find is what you look for. « Les abeilles ont été pour nous comme des nuages, chacun y a vu ce qu'il voulait y voir ». Without a set of criteria, it is just an unfathomable mountain of data. So, how do we know if so and so is looking for the correct signs of diversity, and if the diversity they find is connected in any way to behavior? We have to take their word for it.

One thing that has been discovered is the phenomenon of genetic drift. Populations can drift apart genetically to the point that they can be distinguished by the differences in the genomes. However, this does not mean they are different in ways that affect behavior or survival. The genes for survival tend to be "conserved" while areas of the genome that are not critical for survival tend to accumulate mutations simply because they don't impact on survival one way or another.

An example of this is the Arnot Forest bees. Seeley et al showed that they were genetically distinct from commercial hives in the vicinity. This raised two red flags for me. One, does the difference really reflect anything other than drift? Two, they were comparing them to commercial bees which had probably been requeened regularly with California stock. I know the beekeeper who has most of the hives in the vicinity and this is what he does. You would expect unmanaged bees to have different genetic makeup than managed, unless they had just swarmed out of the managed hives. 

But in the end, lack of genetic diversity makes no difference if there is no verifiable symptom. We know that inbreeding in bees can produce profound effects. Zayed and Packer (2005) attributed increased extinction risk to the effects of the "Diploid Male Vortex." The production of diploid males can initiate a positive feedback cycle that leads to rapid extinction. 

PLB

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