Re: HOW ARE RATS AND HUMANS SIMILIAR AND WHY DO SCIENTISTS TEST ON RATS?

Jacquie,
      Great question.  Rats and humans seem like very different 
animals, but in actuality, we have more in common than we have 
differences. Humans and rats both belong to the class Mammalia, or 
mammals, so we bear and nurse live young, are warm-blooded and 
have body hair.  The two species are also similar anatomically, 
having similar organs and general body plan.
      Both are omnivores, which means that both have very diverse 
diets-  eating meat, grains, vegetables, nuts etc.  Rats can eat just 
about anything we can and some things we can't.   Because of our 
varied diets and resourcefulness, both humans and rats are quite 
adaptable, so we both live in virtually every environment.   Everywhere 
humans have gone in the world, rats have followed, living off the 
same food supply and our refuse.
     We also tend to fall victim to the same diseases, so we spread 
them to each other.  Rats spreading disease have caused more 
deaths than all the wars in history combined.  We have both been 
known to spread plague, typhus, trichina, infectious jaundice and 
many other diseases.   
    As for your second question, scientists test their research on rats 
precisely because they are so similar to us.  We can pretty much 
assume that anything that is bad for one is probably bad for the other, 
too.  There is no doubt that we have expanded our understanding of 
anatomy, psychology, chemistry and disease through experimentation on rats.  
There is definitely a doubt as to whether this practice is ethical or not.  I 
guess it all depends on if you believe in the advancement of medicine and human 
knowledge at the expense of the rights of other animals.  
	    Here are some sites on the subject that you might find helpful: 
www.sciam.com/0297issue/0297forum.html
www.peta-online.org

Good luck with your project,

Paul Barrett
Lead Science Demonstrator
Pacific Science Center