Nightly News | September 05, 2012
>>> we're back from charlotte with that major scientific breakthrough we mentioned at the top of the broadcast that could explain and change so many things. even the experts have been trying to figure out about our health, why some people get sick and why others don't, for starters. a report from our chief science correspondent robert bazell .
>> reporter: it's as though after decades of looking at the darkness of space, a fantastic new telescope has revealed new galaxies, allowing us to see millions of undiscovered planets. this is not about outerspace. it's biology, genes, our cells.
>> this is the first comprehensive look at how the human genome , that dna instruction book inside of all our cells actually carries out functions.
>> reporter: until now scientists have only concentrated on a small percent of genes. they call it junk dna , not understanding its purpose. today's discovery shows the so-called junk contains millions of switches that turn on and off other genes.
>> i don't think it's junk anymore. i think it's actually -- in a sense it's the gems of the genome or most valuable parts of the genome.
>> reporter: the new way of looking at human genome or our dna, to determine a newborn's eye color , height and diseases later in life ranging from alzheimer's to heart conditions. it will also give scientist as new road map to find treatments for those and hundreds of other diseases. the research also solves a great mystery in biology, how we humans are so different from other animals when we share many of the same genes. no one can predict when the new understanding will lead to better treatment and cures for disease. but in the history of biology, the understanding of our selves, scientists see this as a revolutionary moment. robert bazell , nbc news, new york.