The art of disguise - how people can imitate others' facial structures and mannerisms

Vocal manipulation - how a person can disguise their voice without the aid of any gadgets.

DNA - how to determine whether people are related through the DNA analysis of skin scrapings and blood.

Try searching in the foresics section, or under paternity cases, both places where they use that sort of testing. Eventually you should be able to get some details.

I've never looked at the actually methogologies used those fields, but as far as biochemistry techniques go there are some set methods for sequencing. This I have learned from my years as a chemistry major with some periods dabbling in the biochem arena.

Extract DNA from you blood or skin cells. Then cut it into to managable sized pieces using sequence specific restriction enzymes (ie. protein complexes that cut the DNA strands a a partiular base pattern, say AATG or GCTC. There are lists of these in any biochemistry or many celullar biology text books). Then you separate them by size (gel electrophosis most commonly). Then cut the fragments usinging different enzymes that cut only at a specific base (A, T, C, or G). Use each of these individually, and when you compare the results you get a map of the sequence that can be compared to others. How well if compares (and I'm sure there are published percentages for this) determines if people are related, or if it's the same person's DNA.

Starting with a entry level text book and reading about DNA will probably be very helpful if the ideas I described sound very unfamiliar. Discovery magazine used to run a lot of medical mysteries and biochem stuff so that might be helpful too (I haven't read it in several years though, so it may not even be around anymore -- but there are always back issues, and it's a much more accessable magazine than I think Scientific American is)

Hope that gives you some more places to look.

GZ

Facial changes---watch Jim Carey or any of the others that mimic other people---it should be somewhere under acting. I don’t think you will find much on physical changes---unless you want to go with the B.S. Fairy. There is magic, the unexplained (the X-Files did one on physical changes that tried to explain it through science), or some sort of mask.

Good luck

Try Dogpile.com they are a very good search engine.

I'd recommend looking up disguise + makeup for your first question. (You might also search at Amazon.com for makeup--I think there was a book out just recently about how Hollywood makeup artists can make women look enough like famous movie actresses that people were fooled. If you can find the title for that book and get it from the library, it may help a lot.)

What Shawn said about voice.

http://www.getspfx.com/

They know the whole process, from making a plaster cast of the head to sculpting custom prosthetic appliances to applying them and blending them to look real.

The Cybergraphic Designs website has a question and answer section. Right now they have only been asked one question, its answer might help you quite a bit. Otherwise, maybe if you ask a question they will choose to answer it.