Re: can you explain pedigree diagrams and how they are used

Pedigree charts are a simple way for geneticists to see how people 
in a family are related to one another. A geneticist interviews a 
member of a family and asks about her/his relatives. 

A set of  standard symbols are used - circles for females, squares for 
males, a diagonal slash to indicate someone who is dead, and so 
on. Lines link people who are related (except for parents who have a 
line joining them but are nevertheless not related).

 http://
www.sc2000.net/~czaremba/labs/pedigree.html
 http://esg-
www.mit.edu:8001/esgbio/mg/pedigrees.html
 http://
www.biology.arizona.edu/human_bio/problem_sets/human_genetics/05t.htm