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

[Christine_Janis@Brown.edu: Fwd: Re: Dale Russel interview on NPR today (Friday)]

Christine Janis is not subscribed to the dinosaur list, so her
messages won't get through without assistance.  I send this one along
only to alert people of the cross-talk.  I will not forward other such
messages.  If you want to see further discussion on VRTPaleo, please
subscribe to that list.  You do it exactly the way that you'd
subscribe to the dinosaur list only you'd put VRTPaleo instead of
dinosaur in your subscription line (the administrative address is the
same).  If you forgot how to subscribe to the dinosaur list, see:


-- MPR

------- Start of forwarded message -------
Date: Fri, 21 Apr 2000 10:25:04 -0400
From: Christine Janis <Christine_Janis@Brown.edu>
To: vrtpaleo@usc.edu, dinosaur@usc.edu
Subject: Fwd: Re: Dale Russel interview on NPR today (Friday)

>Apologies in advance for list duplication...
>Dr. Russell was also interviewed on this mornings Today show.
>They showed a nice 3d image of the "heart" and discussed what endothermy in
>this animal could have meant to its lifestyle.  His key moment was bringing
>up the single aorta that he claims is visible on the imaging.

        Guys, please note that this supposed heart structure (divided
ventricle and single aorta) is reflective of *high blood pressure*, not
endothermy per se. High blood pressure is necessary in endotherms because
they need a high rate of blood supply. However, large animals such as
(many) dinosaurs, with long necks and/or heads held high above the ground,
would also need high blood pressure to get blood to the brain, regardless
of metabolic rate.

        There is no simple functional correlation of a single aorta with
endothermy. This heart structure, fascinating though it may be, says
nothing about dinosaur metabolism, nor does it illuminate the issue of
bird/dinosaur relations.


Christine Janis
Professor of Biology
Box G-B207, Brown University
Providence, RI 02912

phone: 401-863-2215
fax:   401-863-7544
email: Christine_Janis@Brown.edu
------- End of forwarded message -------