epicbattle

I'm curious if their has been any research done on endangered animals genetic diversity. This concerns me when I hear on the news that there are less then X amount of a species. Is there a critical limit to how many animals must exist to preserve diversity? Even if we brought their numbers back, wouldn't they still be a "living dead" species? And if there is some kind of limit has research been done on saying that, as heartless as this sounds, this animal isn't worth saving? Also, has anyone had any kind of progress of mutating a species a little tiny bit to create some diversity? Any literature on this matter would be of interest. Thank you very much.

Sorry if this is the wrong place to be posting this question. I'm new to the forums. I haven't had chemistry since Sophomore year of high school. So it's been about 8 years. I'm trying to brush up before I take my placement exam for college. My question is that I can't quite understand how you find different cation values for metals. i.e. In trying to name Fe(N O3)3 it is iron (III) nitrate. How do I know when it is supposed to change it's charge value? Sorry if this is a simple question. I do not have a teacher, I am trying to self learn all of basic chemistry. Please feel free to recommend any helpful chem sites or forum pages. Thanks.