Three Intriguing Nature Papers

["Steve Brusatte" <dinoland@lycos.com>]

Hey,
Three interesting papers were published in today's issue of Nature.  Here are 
refs and brief comments.  Unfortunately, none deal with dinosaurs per se, but 
all three are intriguing.

Detection of carbonates in dust shells around evolved stars
F KEMPER, C JÄGER, L B F M WATERS, T HENNING, F J MOLSTER, M J BARLOW, T LIM & 
A DE KOTER
http://www.nature.com/nlink/v415/n6869/abs/415295a_fs.html

For those geology buffs on the list: obviously, carbonates form by the 
weathering of silicate rocks in an aqueous solution.  Some carbonates have been 
found in asteroids and interplanetary dust particles, most of which have been 
interpreted as being formed through aqueous alteration. However, based upon 
calcite and dolomite found in the dust shells of evolved stars, the authors 
believe this method may not be the only one by which carbonates are formed.  
Therefore, carbonates found throughout the solar system may not be foolproof 
evidence that liquid water was once present.  An important paper, IMHO, 
especially for those interested in the possibilities of extraterrestrial life.  

Scaling effects in caudal fin propulsion and the speed of
ichthyosaurs
R MOTANI
http://www.nature.com/nlink/v415/n6869/abs/415309a_fs.html

Motani discusses the evolution of tuna-shaped (thunniform) body plans in four 
separate, unrelated groups of vertebrates: tunas, whales, lamnid sharks, and 
parvipelvian ichthyosaurs.  He presents a mathematical model that is contrary 
to hypotheses that state thunniform tails were naturally selected for their 
high aspect ratios.  Motani also discusses the Jurassic ichthyosaur 
_Stenopterygius_ and its similarity to modern tunas.  

Sexual selection: Male displays adjusted to female's response 
GAIL L. PATRICELLI, J. ALBERT C. UY, GREGORY WALSH & GERALD BORGIA
http://www.nature.com/nlink/v415/n6869/abs/415279a_fs.html

The authors, in a brief communication, discuss their use of robotic females in 
a field experiment that demonstrated display behaviors of male satin 
bowerbirds!  They found that the birds do not always display at "maximum 
intensity," but rather successful males "formulate" their displays in response 
to signals from females.  More interesting mating behavior from extant 
theropods.  

All worthwhile reading.

Steve

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Steve Brusatte-DINO LAND PALEONTOLOGY
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