[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Archaeopteryx feathers and origin of flight based on 11th specimen

I slight asymmetry is functionally no different than symmetry, there is no
positive selection for *symmetry*, either.

And slight asymmetry may help with the maintenance of feather curvature,
with imbrication when the wing is formed, etc.

On Fri, July 4, 2014 3:22 am, Martin Baeker wrote:
>> Yes, the structural spar tends to sit closer to the leading edge
>> than the trailing edge of the wing. The mechanical importance of
>> this for bending and torsional resistance is well understood, and it
>> does not apply if the leading edge is only slightly shorter than the
>> trailing surface.
> If this is so, what other advantage does asymmetry have? For if
> there were no advantage to a slightly asymmetric feather, it seems
> difficult to envison the evolutionary path to full asymmetry. (And
> no, I dont accept "display function" as an answer here :-)  )
> Martin.
>                     Priv.-Doz. Dr. Martin Bäker
>                     Institut für Werkstoffe
>                     Technische Universität Braunschweig
>                     Langer Kamp 8
>                     38106 Braunschweig
>                     Germany
>                     Tel.: 00-49-531-391-3065   <===  NEW phone number!
>                     Fax   00-49-531-391-3058
>                     e-mail <martin.baeker@tu-bs.de>
> http://www.tu-braunschweig.de/ifw/institut/mitarbeiter/roesler1
>                          http://www.scienceblogs.de/hier-wohnen-drachen

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
Fax: 301-314-9661

Faculty Director, Science & Global Change Program, College Park Scholars
Fax: 301-314-9843

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA