Re: Waimanu & avian evolution (comments)

[Michael Habib <mhabib5@jhmi.edu>]

So, I have few comments/questions for all you list-members now that I 
have read through the Slack et al. Waimanu paper.  The real meat of the 
manuscript is the date calibration and phylogenetic hypotheses, but at 
the moment I want to draw attention to a few of the ideas raised by 
their discussion of neornithine/pterosaur/archaic bird competition.

1) Is their method of estimating 'decline' a good one?  The authors 
looked at character evolution (body size) in pterosaurs, but the real 
emphasis seems to be on apparent species diversity.  However, this is 
not an evenly applicable measure.  Due to locomotor differences, it 
should be expected that pterosaur species diversity would be low 
compared to most bird groups (seabirds possible excepted), but may 
still have been represented disproportionately in biomass or geographic 
range.  Any thoughts?

2) The authors make at least one comment about the possible impact of 
early Falconiforms (which they have placed in the Cretaceous in this 
analysis...I find that dubious for reasons that can be discussed 
later).  Even if the authors are correct about this ancient origin of 
Falconiforms, is there any good reason to assume that the early forms 
were already raptorial?

Of course, I would also love to hear everyone's thoughts regarding the 
dated tree itself, which is ultimately the most important part of the 
paper.

Cheers,

--Mike H.


On Friday, May 12, 2006, at 12:02 PM, Tim Williams wrote:

> This was discussed earlier on this list, but this is the official 
> paper...
>
> Kerryn E. Slack, Craig M. Jones, Tatsuro Ando, G. L. (Abby) Harrison, 
> R. Ewan Fordyce, Ulfur Arnason and David Penny (2006) Early Penguin 
> Fossils, Plus Mitochondrial Genomes, Calibrate Avian Evolution.  
> Molecular Biology and Evolution 23: 1144-1155