RE: Bats Could Fly Before They Had 'Radar'

[Tim Williams <twilliams_alpha@hotmail.com>]

Dann Pigdon wrote:


> This just in: 
> 
> Bats could perform surgery before they had 'Hawkeye'. 
> 
> Bats could cross-dress before they had 'Clinger'. 
> 
> ... and so forth. :) 

 
I was going to write "Q: Why did bats have Radar?  A: Because Hawkeye wouldn't 
pay the ransom".  But yours is much better.  ;-)

 
Anyway, back to the Nature article.  The accompanying summary by Speakman 
actually gives an honorable mention to dinosaurs, by way of post-Mesozoic 
birds...

 
"A hypothesis I favour is that the earliest ancestors of bats may have been 
diurnal, and had visual means of orientation - but were perhaps forced to 
become nocturnal by the appearance of avian predators, shortly after the 
dinosaurs became extinct around 65 million years ago."

 
I don't buy it.  There were plenty of birds around in the Cretaceous, and 
there's good evidence that many of them were predatory.  And the pterosaurs 
weren't exactly whistling Dixie either.  


Besides, AFAIK, most modern gliding mammals are nocturnal, including the colugo 
(often touted as the closest living relative to bats).  Why couldn't the bats 
have begun as nocturnal gliders, then switched to nocturnal fliers some time in 
the early Cenozoic?  Based on Karen Sears's work, the transition from gliding 
to powered flight may have been quite rapid in early bats.


Ref:

Sears, K.E. et al. (2006) Development of bat flight: Morphologic and molecular 
evolution of bat wing digits.  PNAS 103: 6581-6586. 


Cheers

Tim 


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