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

Re: EXTINCTION THEORIES



If you sent mail to the list during the past week or so, most likely
it did not make it to me.  However, some mail queues will hold onto
things even for a week.  Unless there is something urgent, please hold
off on sending duplicates.  There are a few things, however, that have
come in, but did so during a period when the system was only partly
functional.  I will forward those messages if I'm convinced that they
haven't already been distributed.  Please forgive me if I make any
mistakes... 

The following was submitted by Scott Horton.  He was responding to a
question from Dana L. Naldrett relating to a recent episode of
PaleoWorld...

M

  Date: 24 Mar 1995 19:08:13 -0500 (EST)
  From: Scott <HORTON@BCRSSU.AGR.CA>
  Subject: 
  To: dinosaur@lepomis.psych.upenn.edu

  >Similarly, if climate change were responsible, why did the mammals
  >survive, and SOME of the reptiles and amphibians?

  If climate change were slow, the dinosaurs should have
  adapted. After all, there were dinosaurs living in cooler areas like
  Antartica. Essentially, a meteorite impact would have brought on a
  VERY RAPID AND SEVERE climate change. A slow mild type of climate
  change would not explain the extinction of marine reptiles and other
  marine and flora species.
  
  >The last theory relates to the land bridges and the movement of 
  >creatures over them. The theory goes that with the transported 
  >animals came new diseases that killed off the dinosaurs.
  >Dana Naldrett  (naldret@cc.umanitoba.ca)   

  Again, this theory cannot explain the simultaneous extinction of
  marine reptiles and other marine and flora species. Remember that
  although the K/T extinction event makes most of us think of
  dinosaurs, the vast majority of species that disappeared then were
  non-dinosaurian. Also, I cannot think of a single instance of a
  disease completely wiping out a disease. There are always survivors,
  such as during the Black Plague in Europe. This was discussed on
  this list a couple months ago.
  
  Conclusion? Not all the problems of the meteorite impact theory have
  been worked out yet, but the other theories proposed so far have
  more fundamental problems.

  Scott Horton
  Geophysicist/Computer Programmer