What Killed The Mega Beasts?

[MariusRomanus@aol.com]

On Discovery tonight was a show called "What killed the Mega Beasts?"... It was 
pretty good actually. I watched it twice. The show pinned 3 theories for the 
Pleistocene megafauna extinction against each other... Climate, Man, and 
Disease... And believe it or not, the show actually dealt with presenting 
actual evidence this time... Shocking isn't it? :-)  

http://dsc.discovery.com/convergence/megabeasts/megabeasts.html

I'll tell ya what,.... Though I personally believe that it was a combination of 
all three that probably conspired to do the large mammals in (depends on the 
place in the world, time, situation, etc).... and I know that many of you are 
going to throw things at me for this one... But... the disease agent coverage 
that was talked about, especially with an example of how wild dogs and lions in 
the Serengeti became infected with some sort of dog disease from domesticated 
animals... (Nasty, nasty death for the wild animals, mild to no symptoms for 
the domesticated canines)... a disease that almost whiped them out before 
humans came to the rescue with vaccines... really makes me raise an eyebrow to 
Dr. Bakker's ideas on dinosaur extinction via disease agents.... ::Screams like 
a little girl and ducks for cover::

I'm not saying that disease could be the ONLY thing that causes extinction... 
But I think we tend to toss the idea to the side in favor of a magestic 
killer... forgetting about the probability of disease. I know enough to 
understand that disease alone never really does in entire groups of animals... 
There are always survivors... Those that are immune... and Dinosaurs of all 
sizes were prolific breeders.... Large mammals are/were not, so they would have 
been much more vulnerable to population crashes for which replentishing the 
species rather quickly would not have been able to be done.... This leaves them 
even more vulnerable to other forms of calamities... natural and man induced. 
Also, land bridges all through the Mesozoic were coming and going and the 
dinosaurs were mingling... etc etc etc... This has been beaten to death.... And 
for the mammals, Ice Ages came and went... I think the giant mammals weathered 
20+ before they were mysteriously beaten down during the last one!
..!
.. I don't want to get back into a dinosaur extintion brawl, but... What I took 
from the show for the mammals was of the same situation that was for the 
dinosaurs... Multiple agents of one sort or another ganging up to make not just 
a bad day for both groups (they had many of those all through their history), 
but the final extinctions were very very VERY bad days.

But anyway, the show was worth a look see... So, if you get the chance, watch 
it when it's on again.

Kris