I feel like I found this article with near-perfect timing, considering that I am starting a unit on genetics in my Biology classes.  To recap: sadly, after scientists seemed to have successfully created a hybrid clone of an extinct goat (they had preserved cells from the last surviving animal who died 9 years ago), the only kid that survived to birth died shortly thereafter.

I think that one of the valuable lessons here is found in the numbers:

439 embryos were created. 
57 were implanted into surrogate mothers. 
1 survived to term. 
0 newborn clones lived longer than 10 minutes.

Students often ask me, "What's the big deal about cloning?  We've cloned so many animals, why is it so controversial?"  Usually they are asking in reference to human cloning, of course.  When I point out numbers like those above....it makes them stop and think. 

Yes, cloning is great technology.  Yes, scientists have made many advances, especially in recent years.  And yes- for every successful clone, there are many, many clones that didn't make it.  There is still so much that we don't know.