[NatureNS] fly and bee co-evolution

References: <20061020163531.13539.qmail@web36212.mail.mud.yahoo.com>
From: Steve Shaw <srshaw@dal.ca>
Date: Fri, 20 Oct 2006 15:22:55 -0300
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On 20-Oct-06, at 1:35 PM, Paul MacDonald wrote:
> ... Hi Dave and All
> In-breeding or line-breeding will produce the
> modifications that you suggest.

Hi Paul, you seem to be thinking of within-species variation -- my 
point was about the emergence of new species (of mimetic flies) during 
evolution.   The definition of what's a species is difficult these 
days, but a common theme is that different species are those 
'varieties' that can't interbreed and are therefore reproductively 
isolated (not a cast-iron  definition, though, many exceptions) .  The 
species concept these days is tricky, need to get expert advice on what 
the best idea is (I don't think that there's full agreement on this, 
and maybe it doesn't matter scientifically).

> One of the general
> rules of nature is the more closely related the
> parents - the more variation in the offspring. Some
> good some not so good.

>   I don't know where this idea comes from, but if it were true, it 
> wouldn't be possible to isolate different strains of cattle, dogs, 
> pigeons, geese, etc by selective breeding -- the opposite would be 
> true.  Darwin became an expert on this, and used the example of 
> short-term selective animal breeding (to produce extreme true-breeding 
> 'varieties') as a model argument for what he proposed had happened 
> during long-term natural evolution.   The examples from in-breeding 
> are not usually new species, as the various dogs etc can still often 
> interbreed successfully.

> The great majority of the food
> consumed daily in the world has been produced by
> taking this rule into account.

> I suspose you could make the point that the pairing
> with insects is chance!
Maybe this last idea is correct, and it would also be for some birds -- 
those with males that sing and otherwise advertise themselves and their 
territories to prospective females.  Other birds apparently pair for 
life, however, so it is not always a rule.  I flinch at straying into 
this birdy territory myself -- you'd need to get Ian McLaren or someone 
on this, on the extent of lifetime pair-bonding in birds and whether 
this actually runs as a trait in bird families, or not.
Steve

Have a nice fall
> Paul
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
>


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On 20-Oct-06, at 1:35 PM, Paul MacDonald wrote:

<excerpt>... Hi Dave and All

In-breeding or line-breeding will produce the

modifications that you suggest. 

</excerpt>

Hi Paul, you seem to be thinking of within-species variation -- my
point was about the emergence of new species (of mimetic flies) during
evolution.   The definition of what's a species is difficult these
days, but a common theme is that different species are those
'varieties' that can't interbreed and are therefore reproductively
isolated (not a cast-iron  definition, though, many exceptions) .  The
species concept these days is tricky, need to get expert advice on
what the best idea is (I don't think that there's full agreement on
this, and maybe it doesn't matter scientifically).


<excerpt>One of the general

rules of nature is the more closely related the

parents - the more variation in the offspring. Some

good some not so good.

</excerpt>

<excerpt><color><param>000A,0000,0128</param>  I don't know where this
idea comes from, but if it were true, it wouldn't be possible to
isolate different strains of cattle, dogs, pigeons, geese, etc by
selective breeding -- the opposite would be true.  Darwin became an
expert on this, and used the example of short-term selective animal
breeding (to produce extreme true-breeding 'varieties') as a model
argument for what he proposed had happened during long-term natural
evolution.   The examples from in-breeding are not usually new
species, as the various dogs etc can still often interbreed
successfully. 

</color></excerpt>

<excerpt>The great majority of the food

consumed daily in the world has been produced by

taking this rule into account.

</excerpt>

<excerpt>I suspose you could make the point that the pairing

with insects is chance! 

</excerpt>Maybe this last idea is correct, and it would also be for
some birds -- those with males that sing and otherwise advertise
themselves and their territories to prospective females.  Other birds
apparently pair for life, however, so it is not always a rule.  I
flinch at straying into this birdy territory myself -- you'd need to
get Ian McLaren or someone on this, on the extent of lifetime
pair-bonding in birds and whether this actually runs as a trait in
bird families, or not.  

Steve   


Have a nice fall

<excerpt>Paul


__________________________________________________

Do You Yahoo!?

Tired of spam?  Yahoo! Mail has the best spam protection around 

http://mail.yahoo.com 


</excerpt>


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