" idea of how environmental influences affect the expression of genes"
I have no clue why anyone would call such influences epigenetic.  For example in some reptiles sex is determined by the temperature the eggs incubate at.  As the temp increases the hydrogen bonds between the two strands of DNA in a particular control region of the DNA weaken.  At a high enough temp this area becomes so poorly bound that the chemicals needed to translate the DNA into mRNA can now bind and when they bind they result eventually in a protein that causes the animal to be one particular sex.  In the adscence of that chemical the animal is the opposite sex.  Are you now going to claim such hydrogen bonding changes are a form of epigenetics?  If so how do you propose such a change could be transmitted to the next generation?
I will give another example.  Some bacteria digest lactose for energy.  But, lactose is rare in the environment.  So, the genetic machinery that allows lactose digestion is in the normal turned off state when there is no lactose present.  I say normal as turned off is the natural state for all  coding genes.  Now the bacteria encounters lactose in the environment and what happens?  There is a specific region in the DNA that loosely binds lactose and its metabolites.  This binding weakens hydrogen bonds allowing the machinery that makes mRNA to bind.  And the end result is the genes that allow lactose metabolism are turned on and the bacteria burns the lactose for food.  Is this epigenetics and how could the bacteria transmit a turned on gene to the next generation.  Or more basic why would it want to transmit such a useless gene when lactose is usually rare?
Yet, in both these cases it is easy to stand back if you know nothing about the underlying biochemistry and thermodynamics that are going on and speculate that epigenetics must be involved because you can not think of anything else to explain what is happening.  In the temp sex determination all that needs to happen is some epigenetic mark needs to get added to turn off some unknown gene (why was it on in the first place when the normal state is off?)  and that off state results in a different sex.  Real easy to blame such things on epigenetics or to blame local adaptation on epigenetics when in fact the odds of the explanation being right are likely many thousands to one against.

I think we all need to also remember that we know for practical purposes nothing at all about honey bee DNA.  You might recall that President Clinton held a press conference in 1998 (as I recall) announcing we now knew the sequence of the human genome.  He held the conference because the science guys told him to.  About two weeks later all the data from the government sponsored part of the effort was thrown out and no one has looked at it since then because it was absolutely riddled with errors.  Now the government part of the project made many, many vitally valuable contributions to the science of DNA.  Without those contributions we would be several years behind where we are today.  About every three to five years since then someone has announced one more time we now know the human DNA sequence.  Sometime someone will be right.  I have no idea when that will happen.  There are problems in the sequence that current technology simply does not deal with very well.  But we are getting better.  Now look at the honey bee DNA. Those same types of problems in honey bees are hundreds of times worse than they are in humans.  I would guess we will have a half decent sequence for honey bees in maybe 15 or 20 years.

Dick

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html