Quoting Allen Aigen <[log in to unmask]>:

> Yes. the salt-water stickleback fish that were isolated in a small  
> area that became fresh water and quickly evolved to meet the new  
> environment is a great example of evolution at work.  Were any  
> marine snails caught up with them that also evolved to meet the  
> challenge?

* the Sticklebacks were already anadromous, breeding in freshwater, so  
they didn't need to evolve an adaptation from saltwater to fresh. I  
haven't heard of any post-pleistocene colonization of freshwater in  
Canada by marine snails.

For those who want to while away some New Year's time in marginally  
Mollusc-related literature, our annual letter is up under the heading  
of "You can find out more about our activities than it's likely anyone  
would legitimately want to know..." at http://pinicola.ca/aboutus.htm

fred.
=========================================================

>   We have many cases of isolated populations that are distinctive,  
> but we usually lack the necessary data to say whether these are new  
> species (or subspecies) or just geographic variants.Some groups seem  
> to evolve quickly, like the conidae, which are specialists in their  
> feeding, where small changes in the toxins produced by a geographic  
> subgroup can apparently quickly lead to genetic isolation and  
> speciation.  Other groups are generalists, like Fasciolaria and  
> Busycon, where it takes long periods of isolation to effectively  
> form a new (sub)species.  Always more questions come up the more you  
> answer.  
> Allen Aigen
>
>
>       From: steve rosenthal <[log in to unmask]>
>  To: [log in to unmask]
>  Sent: Friday, January 1, 2016 12:55 PM
>  Subject: Re: [CONCH-L] Crepidula sex change
>
> the linked-to article on the Smithsonian page herein about the
> Stickleback fish in ALaska was equally interesting, and more important
> perhaps from an evolutionary perspective....actual change/speciation
> occurring in the blink of an eye, relatively speaking.
>
> On 12/31/15, Allen Aigen
> <[log in to unmask]> wrote:
>> Ain't love wonderful?
>> The power of touch: Sex-changing snails switch sooner when together
>>
>> |  |
>> |  |  |  |  |  |  |  |
>> | The power of touch: Sex-changing snails switch sooner wh...Many animals
>> change sex at some point in their lives, often after reaching a certain
>> size. Snails called slipper limpets begin life as males, and become female
>> as t... |
>> |  |
>> | View on www.sciencedaily.com | Preview by Yahoo |
>> |  |
>> |  |
>>
>> Allen Aigen
>>
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       Mudpuppy Night - http://pinicola.ca/mudpup1.htm
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