This is a side project I've been working on for a few months. There a
re alot of phylogenetic trees floating around now a days, one of the major
misconceptions of these 2D trees is that convey an element of time. Altough an
evolutionary rate constant is implicit in the many of the algorithms used to
construct these trees there is no time depicted. The 2D trees found in the
literature would be equivalent to looking down on the top of the 3D tree
This tree is by no means supposed to be quantitative with regards to
the changes per positon (x-axis; diversity) or the time axis. The primary goal
of this tree is for educational purposes. The dates of the y-axis are culled f
rom a very superficial search of the literature. The present is depicted as a
plane intersecting a phylogenetic tree. Extant species are those that which
intersect hte present time plane. Those branches not breaking the plane
represent extinct species. It is kind of interesting to contemplate the number
of extinct bacterial and archeal species considering how much more abundant
they are compared to eukaryotes.
The file is a uuencode, gif, grayscale file. I also have a black and
white pict. file available.
I would really appreciate any comments at
IN%"lepppaul at studentL.msu.edu". Please don't send any mail to the address in
teh header. I would especially like to hear any ideas on how a time element
could be added to phylogenetic programs.