The new traditional ways of doing phylogeny trees has presented some
problems, that taxonomists are still trying to sort out and refine.
One or several inactive regions (interons)of plastids are usually
used. Sometimes an interon in mitochondria is also used. In more
thorough studies (Goldblatt for example) will use nuclear DNA introns
as well. Each sample will provide a different tree, and a consensus
tree is presented. That is one that covers most of the data and is
most parsimonious (having fewest mutations/revisions). One of the
biggest problems is trying to put all this into linear branched tree.
It is becoming more and more obvious that a lot of species are not
descendents of one parent population. This is what is called
reticulated evolution. A new species can often result from
hybridization between species. As in case of I. versicolor (setosa and
virginica), I. pumilla i. nelsonii and robusta, for a few examples.
There is also new species by introgression, as in louisianna iris. This
is where genes from one species is moved into another, giving it new
traits aiding survival, resulting in a new species which is primarily
derived from one parent with additions. So a traditional linear
branched phylogeny tree doesn't capture this, and taxonomists are
driven crazy tying to make it all fit onto this sort of tree. There
have been a few people advocating for reticulated phylogeny trees, but
this is slow getting accepted.
A few people (Harboune for example) are looking at biochemical
products of plants and connecting this with evolutionary
relationships. By this he has identified several reticulate iris
species in Italy.
There is still a ways to go to get it all sorted out.
Chuck Chapman
-----Original Message-----
From: Sean Zera <zera@umich.edu>
To: iris-species <iris-species@yahoogroups.com>
Sent: Mon, Feb 3, 2014 12:40 pm
Subject: Re: [iris-species] Classification of Iridaceae
Â
There is a newer, expanded version of that cladogram
here:http://www.rsabg.org/iris/phylogeny
Some of the relationships are fascinating (though perhaps not too
surprising). Nepalensis, evansias and junos are each other's closest
relatives, while the other bulbous species are related to spurias. As
was suggested by Anderson in the '30s, tridentata and virginica are
closely related. The placement of siberica seems unlikely. It's
interesting thatÂcristata/lacustrisÂis the sister group to the rest of
the beardless, andÂI'm surprised Iris verna didn't make it into the
study. The Tenuifoliae are missing as well, but that's less surprising.
Anyone have access to her papers?
Wilson, C. A. (2004). Phylogeny of Iris based on chloroplast matK gene
andÂtrnKÂintron sequence data.ÂMolecular phylogenetics and
evolution,Â33(2), 402-412.
Wilson, C. A. (2011). Subgeneric classification in Iris re-examined
using chloroplast sequence data.Âtaxon, 60(1), 27-35.
Sean Z
On Sun, Feb 2, 2014 at 11:08 PM, David Ferguson
<manzano57@msn.com> wrote:
Â
Here is a rather confusing but interesting tidbit which you may have
seen already. Not a classification, but related.
Â
Dave Ferguson
Â
Â
To: iris-species@yahoogroups.com
From: rbartontx@yahoo.com
Date: Sun, 2 Feb 2014 08:29:36 -0800
Subject: [iris-species] Classification of Iridaceae
 Hi All,
I'm thinking about a presentation for SIGNA on the "other" irids, and
was considering organizing it by tribes within the family. I have
Innes, 1985, who cites Goldblatt, 1971, as the most recent treatment of
the family. Does any one know of a more recent treatment of the
Iridaceae?
Rodney
