Backyard birdfeeders driving avian evolution

To: "'L&L Knight'" <>
Subject: Backyard birdfeeders driving avian evolution
From: "Andrew Bell" <>
Date: Mon, 7 Dec 2009 22:25:53 +0930
Indeed, maybe I wont have to wait quite so long to tick that trio of
Gouldian species 

-----Original Message-----
From: L&L Knight  
Sent: Monday, 7 December 2009 8:54 PM
To: Andrew Bell
Cc: Birding Aus
Subject: Backyard birdfeeders driving avian evolution

In species that breed every year, I would think that consistent divergence
could lead to speciation in time periods of the order of thousands of years.

Regards, Laurie.

On 07/12/2009, at 7:30 PM, Andrew Bell wrote:

> Hi all
> Some more thoughts on a very intriguing subject, it was an interesting 
> article.
> Google: evolution rapid finches
> There are many examples of such minor changes in bird populations 
> being cited as evidence for observable evolution, including melanotic 
> urban rock doves.  Darwin hypothesised that the development of all  
> species was due to the gradual accumulation of just such minor 
> variations over very long periods of time. He also investigated at 
> length the inheritance of variation in domestic animals including 
> dogs. He didn't have any knowledge though of how novel variations 
> appeared. He would have revelled I think in modern genetics - 
> rearrangement of genes, mutation of DNA and pondering of the possible 
> role of all that "junk" in controlling and changing gene expression.
> "Species" is of course an arbitrary division of a continuous, if 
> mostly extinct, chain of variation, with more than one definition to 
> choose from - the old one of genetic isolation certainly doesn't work 
> very well, many "species" hybridize and produce fertile offspring. In 
> the example discussed it is entirely reasonable to suppose we are 
> seeing the first discernable link in this chain  - we're just not 
> going to be around nearly long enough to observe separation into 
> "species". If we had observed this process in warblers, would we yet 
> recognise as speciated the Willow Warbler and the Chiff Chaff, of for 
> that matter the Northern,  Mangrove and Grey fantails?
> The recent ABC Catalyst on Gouldian's certainly set me thinking. It 
> discussed the strong tendency of Red heads to select Red heads as 
> mates with subsequent increased breeding success. The explanation 
> offered was of previous geographical isolation and merging of diverged 
> populations when the climate changed. It certainly suggests early 
> speciation and raises the possibility of continued now sympatric 
> speciation within actual flocks. Who knows, if they survive another 
> million years of climate change there might be an additional "tick" to 
> wait for.
> Cheers
> Andrew Bell
> -----Original Message-----
> From:  
>  On Behalf Of Peter Shute
> Sent: Monday, 7 December 2009 8:24 AM
> To: ; 
> Cc: ; 
> Subject: Re: [Birding-Aus] Backyard birdfeeders driving avian 
> evolution
> I don't know much about genetics, but I was wondering the same thing 
> (I think).
> Dogs have been selectively bred till we have an astonishing range of 
> breeds of varying sizes and traits, that breed true. Yet I'm told if 
> you let them inter breed they quickly revert back to something like 
> their ancestors.
> I've never heard of this being offered as an example of evolution.
> Peter Shute
> --------------------------
> Sent using BlackBerry

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