Re: Hierarchal vs Non-Hierarchal Interfaces to Biological Taxonomy
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Sat, 23 Dec 2006 04:23:58 GMT
Message-ID: <yb2jh.36536$cz.537467_at_ursa-nb00s0.nbnet.nb.ca>
>
> One.
>
> Correct.
>
>
>
> Your "at that point, humans, ducks and pigs all share a
> unique recent ancestor" is an incorrect premise. A
> percentage of the human genome (I want to say 8%, but I
> don't remember for sure) came from outside organisms
> like virii, but that doesn't make them our ancestors.
Date: Sat, 23 Dec 2006 04:23:58 GMT
Message-ID: <yb2jh.36536$cz.537467_at_ursa-nb00s0.nbnet.nb.ca>
Larry Coon wrote:
> Bob Badour wrote:
>
> Answering several distinct posts at once here...
>
>
>>>>Which opens the floor to: "How many species did you have >>>>before B went extinct?"
>
> One.
>>>These kinds of questions are always interesting. And they >>>often lead me to the same conclusion, which is that >>>the concept being discussed is a construct of the >>>human mind, and not of the natural world. The >>>very idea of "species" is an abstraction. A useful >>>one, but an abstraction nonetheless.
>
> Correct.
>
>
>>Here's an even better one: Suppose a retrovirus comes along that conveys >>some fitness advantage so that it becomes ubiquitous among a species: >>ducks for instance. Suppose as well that the virus crosses over from the >>domesticated duck population into pigs and humans where it too becomes >>ubiquitous. >> >>At that point, humans, ducks and pigs all share a unique recent >>ancestor. Where does that put us in the taxonomy with ducks and pigs?
>
> Your "at that point, humans, ducks and pigs all share a
> unique recent ancestor" is an incorrect premise. A
> percentage of the human genome (I want to say 8%, but I
> don't remember for sure) came from outside organisms
> like virii, but that doesn't make them our ancestors.
What is the definition of ancestor that excludes them?
> A facinating and related topic is mitochondria. There's
> evidence that it was orignally a separate organism that
> got incorporated into cells in a symbiotic relationship:
> cells provide the sugars that mitochondria need, and
> mitochondira provide the ATP that cells need. So a
> basic feature of eukariotic organisms (animals, plants
> and fungi) was acquired.
Agreed. Are you familiar with Aubrey de Grey's theory of mitochondrial aging? Received on Sat Dec 23 2006 - 05:23:58 CET