Scientists decode human genome's instruction manual

Almost a decade after the human genome project laid bare the building blocks of life, scientists have figured out how they work together to create a living person.

The genome project identified about 25,000 genes that are needed to make a healthy human being, but said nothing about how they combine to produce everything from hearts and minds to legs and livers.

Now researchers in California have published what is effectively the first manual to show how genes are orchestrated inside cells ‑ a milestone that promises to revolutionise scientists' understanding of human development and how it can sometimes go wrong.

Many scientists believe the work will lead to new treatments for life-threatening diseases such as cancer, and possibly mental disorders such as schizophrenia.

The work is also expected to shed light on intriguing studies that suggest how we live today can have striking repercussions for the health and behaviour of our grandchildren. In one study, scientists found that people who smoked as youngsters went on to have grandchildren who reached puberty early. In another, a person's diet appeared to affect the way their grandchildren burned food...