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Live and Let Die - Do you really reduce the gene pool?

53K views 222 replies 22 participants last post by  Daniel Y 
#1 ·
In cases where bees are not given mite treatments, and those who cannot survive are allowed to die, the approach is sometimes called "The Bond Method" or "Live and Let Die".

An argument against this approach suggests that you reduce the gene pool by losing bees that might have other valuable breeding traits.

But given that users of the method are so much in the minority, wouldn't it stand to reason that any of the genetic traits of a given be that are not maintained in the treatment free yards would be carried on in the treated yards in the same area?

Adam
 
#37 ·
I think it's because of what you just said Sol, hard selection for a FEW traits. You lose some diversity in your population of bees as you may lose most of you hives but with open mating I don't see any bottlenecking taking place. I think people would just rather see a more controlled breeding practice of bringing in your desired traits with known stock and introgressing those genes into current apiaries and keeping more of the diversity people like to see in their bees.

The only other issue I see is if something else comes in early in your rebuilding phase and now all your bees are susceptible to that because most of your hives are now base from what few surviving colonies you had left and are probably pretty similar to each other.
 
#43 ·
>>The point I was trying to make is that the only area where "loss through
selection" can occur quickly in honey bee populations, is with homozygosity
in the the sex allele expression. This can happen faster than one would
think.

please rephrase this if you can, preferably in english.
 
#44 ·
Sure.

If you look into how honey bees's heredity for sex determination happens, you'll see that
it is not like us, Mammals where there's an XX or XY chromosome and you have female vs. male, but
it is an actual spot on the chromosome, a set of allelles where the sex is determined.

If the expression is homozygus, the egg is a goner and you have a hole in your pattern. If it is heterozygus,
you have a worker:

X1 X2, X2 X3, X5 X6 = worker
X1 X1, X2 X2, X4 X4 = diploid drone lethal, hole in pattern

so

If you are slecting too hard and too closely, the chances of you getting too many of the above X1 X?, X2 X?, X3 X? being the same is much greater.
That's the "homozygosity in the the sex allele expression"

Its pretty simple really. Think of it as another trait that if you have too many carriers having the same parts contributing to the offspring (virgin X drone)
there will be similar expressions: X1 X1, X2 X2, X3 X3 etc. rather then X1 X2, X9 X5, X12 X4.

So if you are limiting the breeding units in your population through hard selection (BOND or whatever) the chances that the ones surviving will have similar units to donate to the sex allelle in the next generation, is much greater.

Hope this helps ya...

Adam Finkelstein
www.vpqueenbees.com
 
#45 ·
ok, you are going to have to work with me on this one.

sex determination of the bee is different than ours, check.

sex determination of the bee is determined by the queen, (really by the workers who prepare the cells for her eggs, but..), when she lays her eggs.

if the egg is fertilized with a drone sperm, the egg becomes diploid (two sets of chromosomes, one from queen and one from drone), and the expression of traits will be a function of the two influences.

if the queen is 'encouraged' to lay in a drone cell however, the egg is not fertilized with drone sperm, the egg remains haploid (one set of chromosomes, only from the queen), and would be expected to express traits of the queen herself. plus, the genes these drones pass on to the next generation queen, which will be expressed as half of the genes in the next generation worker, will effectively give the mother queen the opportunity to pass her traits on through those drones.

my approach is to select for, well, happy bees. the strong, healthy, get the job done bees. i'll do this by using the best colonies for queens and drones, and relying on drone contribution from the many feral hives in the woods near here.

i believe you are saying this is a good strategy, but i still don't understand the potential problem you submit when selecting for traits.
 
#46 ·
There are a couple of other things that have been overlooked here. Most drones are monoploid, so they only have a single set of chromosomes. They are a clone of the queen, basically. Naturally, a monoploid organism will be homozygous.

The other thing that I don't see in this discussion is the effect of gene expression. Not all genes are active all the time. Genes can be turned on and off by environmental factors, allowing organisms to respond to environmental change without requiring mutation or recombination through sexual reproduction. While genetics is almost infinitely complex because of the number of genes available, genetic expression makes it much more so.

Ted
 
#56 ·
what does she think?
I had a conversation with her about hobby beekeepers setting up methods to create breeding systems for the selection of mite resistant stock. She told me it was not possible for an individual with less than 100 colonies to successfully create such a system without genetic bottlenecking. I disagreed with her for a bit, giving alternative scenarios such as having neighboring colonies in the area (or ferals). She remained unchanged in her opinion.

According to Marla, even if you are able to select for a specific trait (such as mite resistance), after just a few generations you lose so much genetic material that a second factor (nosema, other mites) will devastate the colonies.

The same holds true whether you are actively selecting for a trait (hygienic behavior) or letting them select themselves (bond survivability), considering there is usually one item selecting for survival.
 
#59 · (Edited)
specialkayme,

oh, i was misled, my fault. not good with names.

of course, she's the 'expert'. but i think you and i raise a valid point.

that may be her interpretation, in her not so humble opinion?

i'll have to say i will challenge it, and will attempt to gain more information to accept or refute in my own mind.
 
#61 ·
i'm open to learning more about this.

here's how one could create a bottleneck if they wanted to:

start with just one hive and build it up to a strong double deep and try to have a few drone frames. split the queen out of the hive and make a two frame nuc. let the hive raise 9 good queen cells, and make 9 more nucs up out of it, for a total of 10 hives deriving from that one queen. be sure and locate these far away from any other bees.

if the mating occurs mostly with the drones from the parent hive. all of the bees will be so inbred, or bottlenecked, that the diversity would be all but lost.

in this extreme, and anything that approximates it, you should get marked bottlenecking.

for most operations, especially those around forested areas, i think you would have to try awfully hard to achieve a bottleneck.
 
#86 · (Edited)
i'm open to learning more about this.
can you really reduce the gene pool?

i think yes, but here's what your up against.


the honey bee genome contains around 10,000 genes.

the queen, being female like the workers, has a double set of genes, and the drones have a single set of genes.

the queen's and worker's double set comes about by the combination of an egg and a sperm.

the egg is a cell manufactured in the queen's ovary and is made with only a single set of genes. this single set of genes comes about by the splitting of the ovary cells dna into two single sets of genes. the composition of the single set of genes in the new egg cell has an almost limitedless number of possibilities, because when the dna splits, it can pull the gene from the queen's mothers side or it can pull the gene from the queen's father's side.

when an egg is fertilized, it receives the set of genes from the sperm that the sperm received when it's egg was made in the ovary.

that's 10,000 times how ever many possibilities for the genetic make up of a bee.

this is why every bee, whether queen, worker, or drone, is as much an individual genetically as you and i. our bee populations are comprised of the most genetically diverse individuals one could imagine. we have to try really hard to mess that up.

having said that, and if you subscribe to the theory that genetic diversity is good, than one would want to strive to introduce diverse genetics into their apiary, and avoid flooding with all one source.
 
#62 ·
my bee suppier raises all of his bees from 2 or 3 queen mothers per year. his bees were derived from 6 feral cut outs, 14 years ago, near his location. there are probably many dozens of feral colonies mating with his queens. he has never used any treatment of any kind ever. he sells a couple of hundred queens and nucs each year. they consistantly perform beyond expections, with an ocassional dink of course.
 
#72 ·
so who has no outside drones?
Moving from one hive to ten with no outside drones is the extreme situation. Let me give you a more likely one.

Say you start with 10 colonies, and there are another 20 within mating distance of your hive. Assuming all 30 colonies are headed by different genetic backgrounds, any given queen has no option but to mate with a drone of a different genetic background (unless of course the drone is from the same hive, making him a brother). If a virgin mates with 12 drones, and 29 hives are of different lineages, the odds are greatly in favor that she will introduce new genes other than those she currently has. Now, if you requeen your other 9 colonies with your most productive hive, all 10 colonies are headed by similar (not identical, due to haploid/diploid birth) genetic material. Now the odds of any given virgin mating with similar genetic material increases to 1 in 3 (as 10 of the available 30 hives are sisters). Those 10 similar hives now produce drones that are very similar, which mate with the offspring of the 20 feral colonies, causing them to be more like your hives than they originally were. Then you increase your 10 hives to 30 hives, using sister queens from your most productive hive. Now the odds are actually greater that your virgin will mate with a related drone than with one of the "feral" drones. The entire time, skewing the curve toward inbreeding, and selecting for an isolation of genetic material. If the queen that you selected to head your 30 hives didn't contain a desired gene (mite chewing behavior, excessively developed ovaries, good wax capping patterns), the odds are that you just removed that gene from the available gene pool. And the fight goes on.

You said you couldn't see how a genetic bottlenecking could occur. The above is a very reasonable example of it occurring within 3 years.

Yes, it is extremely rare that you will encounter 0 outside drones. But, if you aren't careful you may have 98% of the drones in a 5 mile radius be from your hives (and all brothers). That (in genetic terms) is very close to having 0 outside drones available.
 
#154 ·
Mark this is what I picked up as well.

I am not sure my comments below directly address the thread(well they do in a round about way at least), but I had to toss this in as I attended the meeting as well with Michael Bush speaking. In the segment on how to select I really found a lot of what he had to comment on interesting. Particularly some comments that be made about bees being gamblers. I will paraphrase so hopefully I capture it (might be covered on his site but I hadn't read this anywhere yet).

All bees are gamblers. Some build up brood early (A), some in the middle (B) and some late (C). Based upon how the year rolls out A, B or C may have the advantage in production, etc. However just because one year a hive is busting loose with bees doesn't mean it is your best hive, rather it could mean it simply gambled and won. If the year had extremely odd weather, out of sink flows, etc. stock taken from this hive could prove a poor producer the following year when weather resume its more familiar cycle. i.e. a hive that builds up super early might out produce in a season with an early spring, then the following year starve due to too much brood and no nectar flows yet. Micheal's suggestion was perhaps we should be looking to avoid selection from the outlier hives, good or bad. Instead choose from the pretty good hives so we are able to hedge a bet against the next big bee crisis with broader diversity in the yard. Reading Specialkay's scenario makes me wonder if selection could have been part of the issue (not enough diversity for the other ailments to be survived).

There was a stark contrast between MB's talk and that of the Russian bee association. Which was very much about selection of the traits "we" deem important. It did come off to me like we could manipulate stock to do what we want if we keep the blood line pure. Working in such a vacuum concerns me. Especially when i listened on and found how working with Russian bees, (according to the speaker -Steven Coy?-) requires working in a vacuum of sorts to preserve the Russian bee genetics. Once the interbreeding occurs (Italian stock or feral, etc.) your advantages are virtually nonexistent and not notable with Russian bees. This to me was a huge warning flag. Not only is it very impracticable for many to attempt this, it really made me think we are setting ourselves up for the same pitfalls with Russians via narrowing as we already experienced with Italians.

All that said I am not sure that the bond method would select too narrowly, so long as the keeper makes the right selection choices and avoids a full on outlier approach.

If I misrepresented anything there I apologize in advance.
 
#69 ·
Letting bees alone to deal with disease is not selecting too narrow. It's the very description of what bees do naturally. Where we could possibly get into trouble is if we breed for only one other trait, like honey production or gentleness or VSH or something. I've heard of queens so VSH that they can't brood properly and have to be supported by adding brood all the time. Is that what people are thinking about when they ask this question (the thread)? It's not like that at all. That's very artificial. Bond method is natural, it's what real bees do, setting aside all the other things we do to them of course.
 
#75 ·
i would not personally requeen the majority of my apiary from one queen mother.
But that was why Marla stated that a successful breeding operation couldn't exist with less than 100 colonies. Taking the top performing 1 colony and requeening all of your hives would spell disaster eventually. But what if you have 20 colonies and you requeen half with the top performing 4? Lets say you continued to do that for several years. If every year, one of the original four becomes "non-performing", and is replaced by a sister queen, within 3 years you've eliminated 87.5% (roughly) of the available genetic material from the mating pool. Continue on for a few more years and you are closer to a 98% removal.

That is discounting colonies from outside your operation, but eventually, with enough growth, the drones from your colonies would flood the DCAs, which would turn the ferals into the same genetics as your hives, further inbreeding your operation.
 
#74 · (Edited)
Actually due to the other genetic factors. the mating of a queen to it's brother is about the same thing as a female mating with it's own half clone. You can pretty much consider the drones clones of the queen that produced them. This does have the effect that bees have figured out how two females can mate and produce offspring. ever thought of that? The true Amazon.

Anyway this woudl result in a drastic in breeding effect and it is highly likely such genetic pairings could survive. The offspring woudl be subject to a wide variety of mutations and deformities.

In addition queens do not mate with just one drone. making it even more unlikely that every mating would be with a brother. There are other factors that prevent the likelihood that brother and sister will mate but they are not as well known and as far as I know not as well supported. One of them is that drones and queens travel significantly different distances during mating flights. As much as a two mile difference from some sources I have seen.

It is still pretty amazing that the bees has managed in effect to figure out how to get female to mate with a female via a surrogate carrier of one of the females genes and produce offspring.

One very interesting point in all this. Where did that female gene come from? If the queen only has a male gene. how did it become a female gene in the drone. I suspect the queen actually has a female and a male gene. but to produce a female bee (worker) it requires two doses of female genes. One from the queen and one from the drone to produce a female bee. So in actuality the drone is an exact clone of the queen except that it has only one female gene resulting in a male offspring.

I may very well be wrong but if I am right then the genetic make up of a queen woudl be XY X being male Y being female. The genetic makeup of a drone, any and all drones are also XY. Remember a drone is genetically identical to the queen that produced it.

So a queen that lays an unfertilized egg made an egg with XY chromosomes. Resulting in a male offspring. it takes two Y's to make a female. But when that males sperm is added to the egg of any queen you now have an XX YY chromosome. you now have the two y's required to produce a female and a female is the result. you do not end up with half females and half males because a double Y is dominant. This would demonstrate both dosage and dominant qualities of chromosomes.

Another way it might possibly happen is that bees only have one sex gene. the queen has one. the drone has the other. in this case we will call the chromosome Y. one Y results in a male. two Y's result in a female. Again allowing every drone to be a clone of the queens genetics but when those genes are combined with the genes of another queen. female offspring are the result

It also makes since that a female would have twice as many Y's (Whys) as a male. Women are always full of questions.

Okay I am ducking now.
 
#77 ·
Where did that female gene come from? If the queen only has a male gene.
You are losing me Daniel.

then the genetic make up of a queen woudl be XY X being male Y being female. The genetic makeup of a drone, any and all drones are also XY. Remember a drone is genetically identical to the queen that produced it.
That's not how it works. Female eggs (queens, workers) have 32 chromosomes. Male eggs (drones) have 16 chromosomes. The male can not carry all 32 chromosomes the queen had.

http://www.glenn-apiaries.com/principles.html
 
#76 ·
fortunately, a queen will never mate with her own drone/clone offspring, because she has already mated before he was born.

as far as mating with a brother goes, at best a virgin queen might find herself mating with an occasional half brother. even this half brother would like have got a different set of genes than his half sister, because when the queen's eggs are formed, the genetic material is a mix from both the egg and sperm that made her. i.e. every egg that the queen produces has it's own unique set of genes.

in this species, the x and the y do not apply, it's haploid expression and diploid expression.

i have learned recently the the cape bee can make more females by combining two sets of female gametes.
 
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