. >> sean carroll: just the study of ancient d.n.a.nly broke onto the scene 20 years ago or so-- the idea that we could harvest d.n.a. from extinct creatures, from fossil bones, learn something about the past. >> stahl: sean carroll, a professor of molecular biology and genetics at the university of wisconsin, says that, like so many things in the field of d.n.a., the progress has been staggering. one surprising discovery has been the value of ancient hair. scientists recently discovered that the hair shaft seals d.n.a. inside it like a biological plastic, protecting it, and making hair a rich and plentiful source of genetic information. does that mean that you can take extinct animals... i mean, there's hair in museums? >> carroll: right, yeah. >> stahl: and get the genetic sequencing? >> carroll: possibly. and especially if those animals were preserved in any way, there's a good prospect of that. it's sort of like "c.s.i.," you know? how good is this forensic material? can you get good d.n.a. information from older and older and olde

sean qanavan, you'll always be very missed. >> and my dad, john candell awe miss you and love you so very much, tons and tons. >> rosa marie carlson. >> marc steven carney. >> joyce carpleto. >> jeremy carrington. >> michael carrolljoseph carson jr. >> christopher mickial carson. >> angela c. carter. >> james marcel cartier. >> sharon carver. >> vivian castle. >> john francis. >> paul casio. >> lily ann casey. >> william joseph cashman. >> william otto caspar. >> and my amazing and beautiful daughter, judy hazel cantillion ferndandez. judy, you gave us so much joy. we wish you so much -- miss you so much. you'll always be in our hearts. your nephew, aunt emma, tim and your nieces, emily and avery love you. >> and our son, louis anthony kapparecchi, a husband, a brother and loving father to christina and lauren. your love and memory. >> capriano. >> jose ramon. >> richard g. catarelly. >> christopher sean caisson. >> robert jean callfield. >> mary theresa callfield. >> justin cavalier. >> michael joseph. >> jason david caine. >> juan amando sib ola. >> thomas joseph selleck. >> anna centeneo. >> and our mother, marie castalko, we love and miss you. >> and my nephew, kevin nathaniel colbert. kevin, your mom and thr