[Taxacom] How many genera (was Re: Drosophila melanogaster name change?)
Kim van der Linde
kim at kimvdlinde.com
Sat Apr 17 08:50:26 CDT 2010
Please allow me to clarify a few points about what we knew back when we
submitted the application, the changes over time that we actually have
seen, and how limited the effect is on the the circumscription of the
new genera before you claim that our proposal is just based on the
On 4/16/2010 2:47 PM, Karl Magnacca wrote:
> Kim van der Linde wrote:
>> The split of Drosophila is not based on the flavor of the day, but
>> consistent with lots of research done over the past decades.
> Demonstrating that Drosophila is paraphyletic is. The actual
> proposal to split it up *is* flavor-of-the-day, since the
> relationships are not settled (the diagram on your website now shows
> 11 new genera instead of 8 as in 2008). See the difference? If the
> relationships were all clear, the only argument would be about the
> names, which is not the case.
Karl, you are right, with every study, it becomes more apparent that our
original idea is far too conservative, and the longer we wait, the more
genera we have to erect. But our splitting proposal was never meant to
be the be-all, end-all proposal in the first place. That is not how
taxonomy is done to start with. The increased understanding comes
incrementally, but I have seen several people demand from us that we
should know everything before we make any change in the genus
Drosophila. Sorry, the genus is neither untouchable nor God not the
property of someone. The good things is. taxonomy is not done that way.
But to answer you question, yes, we know now more than three years ago.
So, what do we know now that we did not know then:
1. The position of Hirtodrosophila duncani. Based on the literature,
this was expected.
2. More clarity about the position of Dettopsomyia.
3. We have now molecular evidence confirming the inclusion of
Xenophorticella and Zygotrica as expected.
4. And yes, we know now confirmation that the quadrilineata species
group is indeed closer related to the other striped clades.
And what did we already know at that time but were not included in what
has been published until now:
1. The tumiditarsus species group is a separate small clade, closely
related to the other striped clades.
2. The position of the polycheata species group is unclear.
Originally, we wanted to split the genus in four major genera
corresponding with the four major clades (Hawaiian 'Drosophila' =>
Idiomyia; sg Sophophora => Drosophila; virilis-repleta radiation =>
Siphlodora; immigrans-tripunctata => Chaetodrosophilella), with five
smaller genera, all currently subgenera ion the genus Drosophila
(Chusqueophila, Dorsilopha, Dudaica, Phloridosa, Psilodorha). A total of
Now, we want to split the genus in four major genera corresponding with
the four major clades (Hawaiian 'Drosophila' => Idiomyia; sg Sophophora
=> Sophophora; virilis-repleta radiation => Siphlodora;
immigrans-tripunctata => Drosophila), with five smaller genera, all
currently subgenera ion the genus Drosophila (Chusqueophila, Dorsilopha,
Dudaica, Phloridosa, Psilodorha). A total of 9 genera.
O wait, there is no change other than the names (thanks to the ICZN).
What changed is that we now know that some smaller clades might be
outside the new genus Drosophila. In the interim, none of those species
will change its name, so, no confusion there with new names that need to
be changed again.
No, the commission has made my job a lot easier, because retaining the
frequently studied Drosophila funebris as a type species for the
immigrans-tripunctata clade is far easier than to decide which of the
rarely studied available types species is actually appropriate.
To summarize the change in our knowledge with regard to the genus
Drosophila during the past three years, we now have proof that the
quadrilineata clade is indeed not within the immigrans tripunctata
radiation. That's all. And revising the genus does not result in more
name changes that later need to be changed again because they stay in
So, in short, the changes in our knowledge hasn't changed how the genus
is going to be revised while the newer publications confirm what we know
about the phylogeny of the genus and its many included genera.
Kim van der Linde
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