Extending Hennig's Figure 4?

Richard Pyle deepreef at BISHOPMUSEUM.ORG
Sun Sep 14 22:10:20 CDT 2003

Dear List,

A little over a year ago, one fine Saturday afternoon when I was looking for
a diversion, I rambled on about the meeting of genealogy and phylogeny in a
note to this list:


(don't bother reading it...trust me....)

At the time, the words flowed unimpeded from brain to fingertips, while I
blissfully assumed the stream-of-conscious monologue was somehow an original
thought (and in a sense it was, because I was basically making it up as I
was writing).  Since the moment I wrote that, I've been thinking about how I
might represent the basic concept visually, and even got to the point where
I started making some simple sketches.

Quite recently, I came to the realization that my thinking was not quite as
original as I had once naively imagined (big surprise...), when I was
flipping through the pages of the Davis & Zangerl translation of Hennig's
"Phylogenetic Systematics", and came across Figure 4.  Given the
similarities between my sketches and this figure (to be fair, I used black
dots for males, and white dots for females; whereas Hennig used the
opposite), I would have accused him of copying my ideas -- except for the
minor and inconvenient fact that Hennig's version was originally published
some 45 years before my own "original" thought....

...But!...there is hope for me yet!  It seems that Hennig might have missed
out on a perfect opportunity to scoop me entirely -- and that leads me to
the real point of this message (sorry for the long meandering intro....).

Has anyone taken this basic idea of a diagram (showing the transition from
genealogy of sexual reproduction into species diversification) to the next
logical extensions?  That is, has anyone illustrated the alternative fates;
e.g., cases where the isolating event is less...um..."vicariant", and more
gradually drawn-out; or what might happen if/when divergent populations
subsequently hybridize/coalesce/reticulate? Or (for those who either have
freakish memories, or discounted my advice not to go back and read the cited
archive message), has anyone shown it on a larger scale with some "holes" in
the mesh re-closing, while others remain as the genesis of permanent future

I'm trying to get this whole notion of the transition between genealogy and
speciation down in a clever PowerPoint format (for a variety of reasons),
and I want to find out if anyone (besides Hennig) has illustrated it like
this already.

Many thanks, and sorry for the somewhat goofy tone and more or less
unnecessary length of this request.


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