Thread subject: Diptera.info :: Is it the end of Limoniidae?

Posted by proctoss on 14-06-2010 21:18
#1

Phylogenetic synthesis of morphological and molecular data reveals new insights into the higher-level classification of Tipuloidea (Diptera)
MATTHEW J. PETERSEN, MATTHEW A. BERTONE, BRIAN M. WIEGMANN and GREGORY W. COURTNEY
Systematic Entomology, Volume 35 Issue 3, Pages 526 - 545

ABSTRACT

Tipuloidea, the crane flies, are a diverse lineage of true flies (Insecta: Diptera) whose phylogenetic classification and taxonomy remain a challenge. Here we present the results of a quantitative phylogenetic analysis of Tipuloidea based on combined morphological characters (adult, larvae and pupae) and nuclear gene sequence data (28S rDNA and CAD). Forty-five species, from 44 genera and subgenera, were sampled, representing the four putative families of Tipuloidea (Cylindrotomidae, Limoniidae, Pediciidae and Tipulidae sensu stricto). Analyses of individual datasets, although differing in overall topology, support the monophyly of several major lineages within Tipuloidea. Parsimony and Bayesian analyses using individual morphological and molecular datasets resulted in incongruent topologies. Increased resolution and tree support was obtained when both datasets (morphology and genes) were combined, in both combined evidence parsimony and Bayesian analyses, than when analysed separately. The recovered consensus phylogeny was not consistent with any previously proposed Tipuloidea classification, with previous importance assigned to character states shown here to represent losses and reversals seen as a major factor influencing erroneous classification. The results provided here, together with evidence from previous analyses, were used to append the Tipuloidea classification to supported evolutionary lineages. Tipuloidea is presented as two families: Pediciidae and Tipulidae. Pediciidae is recovered as the sister group to all remaining Tipuloidea. Our current phylogenetic hypothesis is not consistent with the existing subfamilial classification of the 'Limoniidae', which is paraphyletic with respect to a well-supported Tipulinae + Cylindrotominae clade, whereas the three 'limoniid' subfamilies are para- or polyphyletic. The recognition of 'Limoniidae' as a valid monophyletic family is discouraged and the subfamilies of 'Limoniidae' are amended and placed within Tipulidae. A revised phylogenetic classification is proposed for the crane flies based on a synthesis of evidence from multiple genes and morphology.

http://www3.interscience.wiley.com/journal/123421861/abstract

Posted by Dmitry Gavryushin on 14-06-2010 21:38
#2

An interesting new work of the Courtney Laboratory Research Group.

Posted by Paul Beuk on 14-06-2010 21:52
#3

Interesting, yes, but unless we want to have the same sh*t happening in insects (and in our case Diptera) as did in plants (many families overhauled and no-one really knowing what genus belongs where and whether a family is still a family) we should perhaps start to accept para- and polyphyletic families or even genera (then we have settled the Drosophila melanogaster issue as well).

Posted by Gunnar M Kvifte on 15-06-2010 08:53
#4

It was us dipterists' idea to have monophyly as a criterion for taxonomic validity to begin with. It is a good criterion, because it makes the classification testable and thus scientific - with the accumulation of additional evidence it gets progressively more accurate. However, for practical reasons we should be very conservative in what we consider sufficient evidence - to maintain a sense of stability, most family- and genus-level groups should be defined on the basis of synapomorphies rather than on clade-based definitions.
I will myself probably continue classifying Tipuloids as Tipulidae, Cylindrotomidae, Pediciidae and "Limoniidae", with the latter family in quotation marks to recognize its paraphyly. A new family-level classification should wait until synapomorphies are found grouping the various "Limoniid" subfamilies.

Posted by Paul Beuk on 15-06-2010 09:09
#5

'Us dipterists' idea' meaning Hennig's? ;) It is certainly a criterion but at times when evolution is hypothesized to have been in many consecutive splits with small groups then we either end up with an enormous multitude of groups at a certain level or we get a very large inclusive group that harbours many different well-recognizable groups that have been in existences for a long time (like McAlpine's proposal to lump Heleomyzidae, Sphaeroceridae and a number of smaller families into Heteromyzidae).

Sometimes it is also good to relaise that what may have seemd a good idea may not be one in all circumstances. Is it worth our while to disrupt the whole classification within orders or families because we want to have our hypothesis of evolution reflected in the classification at all times? Something we can have a nice, long discussion about. :D

Posted by atylotus on 16-06-2010 12:14
#6

Prince would call them TATFKAL (the atypical Tipuloidea formerly known as Limoniidae)

Posted by Louis Boumans on 04-09-2010 19:04
#7

Unlike in the case of flowering plants, there are very few people on earth who are familiar with the terms Limoniidae, Pediciidae, etc. anyway. And of this selected group many will be interested in the outline of the phylogenetic relationships among the larger clades. These relationships are easier to understand and memorise if reflected in the nomenclature.

Posted by bbrown on 04-02-2011 17:44
#8

In my opinion, it is more conservative to recognize the two families, or maybe even only one "Tipulidae". Families are convenience groupings for human understanding (as are all higher taxa), and are the level most non-experts learn. The more people who can recognize a monophyletic Tipulidae, the better. The experts in the group can battle out which subgroupings to recognize at the subfamily level.