Centre of origin digression

[Ken Kinman]

Don and others,
     Your dipteran examples show how important it can be to post-analyze biogeographical data after a phylogenetic analysis (especially taxa at lower taxonomic levels).  Robert's last post indicates that it is the failure of some phylogeneticists to do this that really makes him sad or grumpy.  Of course, biogeography becomes relatively less important at higher taxonomic levels (even genus level for something like bacteria).  Will we ever know *where* Class Mammalia (however one defines it) arose?  Debating that would be largely a waste of time.

    And of course, how much of a fossil record is available also influences how much value we can get from biogeography.  If a mammal family has a rich fossil record, biogeographical information can make all the difference.  In a dipteran family with no fossil record at all and many genera with multi-continent distributions, biogeographical data could be of very limited value.  Every case is different, but I would generally be wary of combined phenogeographical analyses except at population and species levels (and even then would hope that separate analyses would be done as well with the data).  Better to analyze too much than too little.

      I would be interested to know what specific mosquito subgenus and bibionid genus you were discussing.  Especially the bibionid.  Either the genus was once widely distributed (perhaps even in Antarctica?), with only relicts left in New Guinea, Queensland and Central America-----or a species somehow got carried across the Pacific to New Guinea (and evolved independently in that area).  Are bibionid larvae known to raft on vegetation over long expanses of ocean?  Are these bibionids picky about what plants they live and feed on?
  ---Cheers,
           Ken