Farewell to Species - reticulation

[Hubert Turner]

On Tue, 01 Feb 2000 19:31:38 -0800, Curtis Clark wrote:
>At 11:24 PM 00.02.01 +0100, Hubert Turner wrote:
>>Because permanent splits are the only things recognized by a
>>cladistic analysis,  in the ideal case (i.e. when no homoplasies
>>occur to muddle the outcome of the analysis) the cladogram would
>>be:
>>
>>A   B  C  Z     D
>> \   \/   |    /
>>  \   \   |   /
>>   \   \  |  /
>>    \   \ | /
>>     \   \|/
>>      \   /
>>       \ /
>>        /
>>       /
>>
>>because apomorphies cannot be shared by common descent by only Z
>>and D, or by only (B, C) and Z, or by only (B, C) and D. The whole
>
You wrote:
>In real life, this doesn't often happen. Hybrid species or lineages often
>get (or keep) more apomorphies from one parent than the other, so that they
>resolutely cluster with one parent's clade.
Obviously, and I did not add the provise 'in the ideal case' for exactly
this reason. In practice, Z will indeed have more apomorphies in common
with either D or (B, C), and group accordingly, but with the other
apomorphies showing up as either parallel developments or as reversals in
the sister group of Z.


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Dr. Hubert Turner
EEW, Sect. Theoretical Biology & Phylogenetics
PO Box 9516, 2300 RA  Leiden, The Netherlands
Visiting address: Van der Klaauw Laboratory, Kaiserstraat 63, Leiden
Phone: +31-71-5274904    Fax: +31-71-5274900
E-mail: turner at rulsfb.leidenuniv.nl
WWW: http://wwwbio.leidenuniv.nl/~turner/index.html

FROM 18 JANUARY TILL MID-APRIL I WILL BE VISITING THE NEW YORK
BOTANICAL GARDEN AS VISITING SCHOLAR, DOING MOLECULAR
PHYLOGENETIC RESEARCH ON ANACARDIACEAE. THIS E-MAIL ADDRESS
WILL REMAIN FUNCTIONAL DURING THAT PERIOD.
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