domingo, 28 de agosto de 2011

Phylogeny of Tabaninae: A critique to Abu El-Hassan et al. (2010)


Introduction

Tabanidae is a Diptera famyly , which has been reconized the monophyly on basis of molecular information (Wiegmann et al. 2000; Morita, 2008). However, relationships within the family have not been resolved. Abu El-Hassan et al. (2010) based on morphological characters, perform the phylogeny of this family. They did not present a formal phylogenetic analysis, their characters are ambiguous and how to perform the analysis is not adequate. The objective of this study is to evaluate the results obtained by Abu El-Hassan et al. (2010) and compared by a phylogenetic analysis using parsimony criteria.

Materials and methods

For phylogenetic analysis were used 20 terminal taxa and 91 morphological characters recoded from the matrix proposed by Abu El-Hassan et al. (2010), all based on adult morphology. The cladistic analyses, it was implied weights search (Goloboff 1993). with differents concavity values from one to ten using TNT version 1.0 (Goloboff et al 2004). The tree search strategy was an traditional search using tree bisection reconnection randomizing the addition sequence 100 times. Then, made a tree search after jackknife 37%; and, calculated the number of initial groups (those without resampling) recovered after jackknife (Goloboff 1997). Analyzed the character distribution made with WINCLADA 1.00.08 (Nixon 2002).

Results and discussion

All characters presented by Abu El-Hassan et al. (2010) were binary characters, and many of them had ambiguous coding. Most of the characters were recoded binary characters to multistate characters as antennal scape color, antennal pedicel and antennal shaped. The most of the groups recover was implicit weight search with the concavity value of nine. Using this concavity value, we obtained 1 trees (Fit k=9= 8.533). The recovered nodes with each concavity value used are shown in figure 1.


Figure 1. Average number of recovered nodes based on repeating ten runs,
after Jackknife resampling with integer concavity values from one to ten
under implicit weights
Concavity value Average of the shared consensus nodes
1 0,5789
2 0,5789
3 0,6316
4 0,6842
5 0,6316
6 0,6316
7 0,6316
8 0,7895
9 0,8421
10 0,7895


The phylogenetic analysis support monophyly of Tabaninae, however the internal relationships are no resolved. The Atylotus genera appears as monophyletic, contrary to the results presented by Abu El-Hassan et al. (2010) , This relationship is supported by one character, upper and middle calli separated. The character distribution are shown in figure 2, Finally it is recommended to repeat the analysis by expandind the number of taxa (ingroup and outgroup) and characters, as well as review and coding characters.




Figure 2. Analyzed the character distribution made with WINCLADA 1.00.08, Jacknife 37%, k=9.

References

Abu El-Hassan, Gawhara M. M, Haitham B. M. Badrawy, Salwa K. Mohammad and Hassan H. Fadl (2010). Cladistic analysis of Egyptian horse flies (Diptera: Tabanidae) based on morphological data. Egypt. Acad. J. biolog. Sci., 3 (2): 51- 62.

Goloboff, P. A. (1993) Estimating character weights during tree search. Cladistics 9: 83–92.

Goloboff, P. A. (1997) Self-weighted optimization: tree searches and character state reconstructions under implied transformation cost. Cladistics 13: 225-245.

Goloboff, P. A., Farris, J. S. & Nixon, K. (2004) T. N. T:Tree Analysis Using New Technology, Version 1.0. Program and documentation, available from www.zmuck.dk/public/phylogeny/TNT

Morita, S.I. 2008. A phylogeny or long-tongued horse flies(Philoliche, Diptera:Tabanidae) with the first cladistic evaluation of higher relationships within the family. Invertebrate Systematics, 22(3): 311-327.

Nixon, K. C. (2002) WinClada Version 1.008. Sofware implementation. Published by the author. Ithaca. New York. Available from www.cladistics.com