> I went back and read the article in Bee World, can you help flesh this out a little. In the context of this article, what do you think the author was getting at?  I'm wondering why the process of natural selection should be comprehensible to begin with, except maybe in hindsight.

Thanks for writing. Sometimes I wonder if anyone is interested in the stuff I post. One of the hallmarks of a solid scientific theory is that it should be able to let us predict outcomes. The concepts of natural selection and evolution are a little weak in this area. But then, so is weather forecasting. We can say general things but not specific ones. 

Generally species that are more fit will prevail, but we don't necessarily know what that fitness entails. For example, how could we have predicted the situation of Nosema in honey bees? The basic scenario is that N. ceranae jumped hosts sometime before 1970 and in the ensuing decades came to be the only species in A. mellifera, replacing N. apis. But why should this happen, given that apis seems to build up in winter while ceranae multiplies in summer? We would have predicted that they both would thrive and wouldn't even be in competition. 

But back to your question, why should we suppose natural selection would be comprehensible? Well, it's human nature to try to understand everything, make a theory and predict outcomes. But I should mention that the original statement came from an article on African Bees. Probably I should bring in the whole paragraph.

The supposedly enormous differences between the tropical-evolved Africanized and
the temperate-evolved European honey bee may, in fact, not be as great as previously
thought. One aspect in which this assertion is especially demonstrable is the
defensive behaviour of the two types of bees. It is well known that Africanized and
European honey bees show distinct variations in defensive behaviour over time.
Specifically, AHB respond more rapidly and generally in greater numbers. Nevertheless,
defence in AHB and in EHB colonies ranges from mildly to highly defensive. In
essence, not all EHB are mildly tempered, nor are all AHB highly defensive. Although
it should be possible to reduce the defensive nature of AHB over time, we do not
believe that we will be able to select less defensive AHB in the USA in the very near
future. The new gene pool introduced by AHB will not only result in more stings to
beekeepers, but it will also negate many years of selection by queen breeders of less
defensive EHB. Finally, the complex genetic composition of a colony makes it difficult
to determine the criteria at which natural selection operates, nor does it allow us
to comprehend the process of natural selection. 

Dietz, A., & Vergara, C. (1995). Africanized honey bees in temperate zones. Bee World, 76(2), 56-71.

So, the impetus for "comprehending the process of natural selection" is to predict what the ultimate result of the African bee's invasion of the US and its effect on the honey bee population here. Will it become impossible to keep bees in neighborhoods? Will it change everything or just make the work a little bit harder? 

Beyond that, people have been saying for thirty years that "we need varroa resistant bees" and that natural selection can produce them. But can it? Why do people breed plants and animals in the first place? Because natural selection does not necessarily produce what we want. And yet, how can we be smart breeders without understanding natural selection and how it works?

Ironically, it was the study of breeding that led Darwin to develop his theory about natural selection. Hence the term, selection. But does nature really select at all? Of course not. Populations evolve over time; subtle or dramatic changes take place. Some outcomes might be predicted, many or most might not be foreseeable at all. 

Varroa mites seem to be able to evolve or develop resistance to control measures. The European honey bee seems very slow or unsuccessful at adapting to varroa mites. I remember giving a talk once and a question came up about the development of natural resistance. I blurted out "The African bee is nature's plan for the survival of the honey bee." The questioner rightly responded "How do you know what nature's plan is?"

What I meant was, the honey bee is not in danger. If we stepped aside and let the evolution runs its course, it's entirely plausible that the African subspecies would come to be the dominant form of honey bee worldwide. It certainly has better survivability in the face of pests and parasites. Some subspecies are already in danger of being diluted or lost, such as the native honey bees of Sicily:

> One beekeeper, Carlo Amodeo, preserved the last three genetic lines surviving on a few Sicilian islands. He shared them with other producers, and now the Presidium has eight beekeepers. A reintroduction project is being supported by the Sicily Regional Authority. see: http://www.fondazioneslowfood.com/en/slow-food-presidia/sicilian-black-bee/

African bees have been in the US for almost 30 years and yet the outcome is different from what was predicted. Ultimately, No, we don't have to be able to comprehend natural selection. We just have to be able to adapt. But then, a major part of adaptation is to be a factor in the process, not a passive observer. All species are engaged in the push and pull of adaptation to each other. All evolution is coevolution (thanks, Stewart Brand).

PLB

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