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

[squarepeg]

and i thought that drone comment was pretty darn good too, imnsho!

[adamf]

But we're not dealing with a Founder Effect situation, nor is there anything approaching an island. The Bond beekeeper is not isolated, or at least I'm not, and I know of no one who is.

Ahhh geee.

The original questions was one that is more academic then practical, but a
good one:

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

I was answering that really the only way a "gene pool" or a honey bee
population's gene flow would be throttled to the point of damage would be
with pressure on sex alleles, not on "valuable traits" etc. It is a great
question. And sure, if there's open mating and one is using BOND, one
should have no genetic load or genetic bottlenecks.

Of course there's Founder Effect in honey bees--the USA is a perfect
example--honey bees were introduced here--the population is completely
artificially selected. Sure there are pockets of naturally feral bees, but on
the whole, we're influencing the honey bees with our agricultural
selection. I'd like my bees to survive AND make honey AND be gentle--that's
quite a bit of selection pressure I put on the bees I work with.

Island Biogeography is a concept where populations are split from each
other and they differentiate because of lack of gene-flow between them. That
also happens all the time here in the USA. Any commercial operator that's
using bees to make a living is in a sense practicing selection Island
Biogeography-style. Those populations are not under natural selection
--they're under agricultural selection. Much different then feral bees or bees
found in un-managed colonies in the wild.

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.

Any "loss" of traits through hard selection via BOND or non-treatment
scenarios will favor the survivors. Sure those might lack some possibly
good traits, but with open-mating and judicious re-selection, they can be brought
back.

A closed population is a perfect condition which does not exist for the vast majority of Bond style beekeepers. Michael Bush has other people's bees all over his territory, as do I, and everybody else I know of. On a side note, I have ceased bringing in outside queens as I have found them to be of poorer quality than the ones I already have. I will see what effects crop up over the next few years.

Yes, yes right...the closed population point was made to provide
an example where sex allele load can occur quickly without management.
If one is open-mating, one is going to have a very gradual selection
effect on one's population. Gradual is fine. Nothing wrong with
gradual. Most queens that are made properly following all the
necessary physiological rules are excellent. Often that's more
important in untreated success--quality queens can overcome many hurdles.


Adam Finkelstein
www.vpqueenbees.com

[squarepeg]

>>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.

[adamf]

>>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.

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

[squarepeg]

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.

[taydeko]

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

[Solomon Parker]

Of course there's Founder Effect in honey bees--the USA is a perfect example

Not really. The Founder's Effect is predicated upon a very small and isolated population. While this may have been the case for a very short period of time 400 years ago, it has not been the case since then, with new strains of bees being added at many points throughout the time since.

the closed population point was made to provide an example

Examples are good, good for understanding concepts and ideas, but this thread is a question of a real method. As ever the realist, I seek examples which fit or explain reality. I believe you can provide them.

[Solomon Parker]

The other thing that I don't see in this discussion is the effect of gene expression.

I would say that when we are talking about traits, gene expression is what we are talking about ultimately. Perhaps I am mistaken in my understanding.

[squarepeg]

so what's he saying sol, as far as negative effects of selection?

[Solomon Parker]

Squarepeg, I am not convinced of any significant negative effects of selection. Inbreeding, yes, we understand that. But even inbreeding is naturally remedied. Selection happens always.

[taydeko]

I would say that when we are talking about traits, gene expression is what we are talking about ultimately.

Very true, but the presence of a gene does not mean it is expressed. So to go back to the rest of the thread, just because a trait is not expressed in some bees does not mean it is necessarily lost from the gene pool, conditions might just not be right for it to be expressed.

So breeding for particular traits may or may not cause loss of diversity, within a local gene pool, depending on the mechanism that is causing that trait to be expressed.

I think modern (the last 50 years, maybe) breeding methods have caused some loss of diversity among bees, but it seems like there is a resurgence of people raising their own queens, and letting them breed naturally. Treatment free beekeeping is allowing diversity to creep back into the bee population, as is the apparent resurgence of feral bees in various parts of the country.

Ted

[Specialkayme]

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.

Marla Spivak thinks otherwise.

[squarepeg]

what does she think sk?

[sqkcrk]

Peg,

The link to her study can only explain it far better than I ever could. Take the time to read it; great paper. One of her summations is that “chemical treatments of honey bee diseases even if successful at the colony level in the short term have not eradicated the problem of pathogens at the population level". In other words you might be able to kill a few mites but you will do more harm to the bees as a superorganism in eliminating their ability to fight off pathogens and viruses that ultimately will lead to the demise of the colony as a whole.

We don't want to know everything there is to know about beekeeping, we just want to know enough to argue about that which we don't know much about at all.

[squarepeg]

We don't want to know everything there is to know about beekeeping, we just want to know enough to argue about that which we don't know much about at all.

can i quote you on that mark? that's brilliant!

duh, it's the paper mentioned earlier in the thread, and i did 'spead-read' it.

specialkayme, i'll have to give the paper another look. i don't recall her warning of 'bottlenecking', it that is what you were referring to.

[Specialkayme]

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.

[Specialkayme]

specialkayme, i'll have to give the paper another look. i don't recall her warning of 'bottlenecking', it that is what you were referring to.

The paper mentioned in Post #3? That was not written by Marla.

I was not referring to that paper.

[sqkcrk]

can i quote you on that mark? that's brilliant!

duh, it's the paper mentioned earlier in the thread, and i did 'spead-read' it.

specialkayme, i'll have to give the paper another look. i don't recall her warning of 'bottlenecking', it that is what you were referring to.

Sure sp. Actually I was thinging about starting a Thread titled "I don't want to know everything there is to know about bees, ..." I just want to know how tyo keep bees.

Michael Bush spoke a little about bottlenecking this weekend at our meeting, mentioning the lack of diversity w/in the gene pool in North America. I wish I could recall exactly what he said. I'm sure it's on his websight.

By the way, I am amongst those who discuss what we think we know, but only really know enough to get ourselves in trouble. Just sit at a table w/ folks who really know what they know in depth and then you will know not to speak up.

Not that I am trying to dampen the interchange. Proceed.

[squarepeg]

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.

[sqkcrk]

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.

Almost exactly what Michael Bush mentioned this weekend. Interesting.