[Taxacom] Bye bye Crustacea

[J. Kirk Fitzhugh]

Bob,

Re the part of the paper you quote, hypotheses are by definition 
'strongly supported' by the very data used to infer them. It's a trivial 
relation between premises and conclusion - the misapplication of 
bootstrapping, Bremer 'support', etc., notwithstanding. The problem 
however is that any one hypothesis derived from one class of data can 
say nothing regarding other classes of data. As I've noted before, there 
are no rational end runs that can be made around the requirement of 
total evidence. But then, who ever said systematics strives for rationality?

Kirk

On 6/11/2010 2:54 AM, Bob Mesibov wrote:
> Tonight I was pointed at
>
> Arthropod relationships revealed by phylogenomic analysis of nuclear protein-coding sequences
> Jerome C. Regier, Jeffrey W. Shultz, Andreas Zwick, April Hussey, Bernard Ball, Regina Wetzer, Joel W. Martin&  Clifford W. Cunningham
> Nature (Letter) 463 (25 Feb 2010) 1079-1083 (doi:10.1038/nature08742)
>
> What's revealed, among other things, is that Hexapoda nests within Pancrustacea and is sister to Remipedia+Cephalocarida. The tree was built using 62 single-copy nuclear protein-coding genes, which partly explains why it differs from earlier arthropod trees based on nuclear rRNA. Taxon sampling was pretty light (75 arthropods out of how many?) but well-spread.
>
> There are a lot of questions raised by this study, quite apart from the paraphyly issues. Morphologically I find the proposed sister-group relationship for hexapods utterly baffling, but the authors are very sympathetic to my confusion and say
>
> "In conclusion, our phylogenomic study provides a strongly supported phylogenetic framework for the arthropods, but the problem of reconstructing and interpreting morphological evolution within this diverse group remains."
>
> Which might be understood as:
>
> "This is what probably happened. If your morphological studies don't support this framework, you need to do more work on your morphology."
>
> Ummm...
>