The paper on page 88 is a landmark for Ze ‘Ginger’ Cheng: she has never before been a ‘first author’ in Nature. A computer programmer and database administrator at the University of Washington's Department of Genome Sciences, Cheng spent most of the past year furiously writing computer code. The fruit of her labour is an analysis of DNA duplication differences between human and chimp.

Cheng was looking for duplications of DNA that appear in both genomes, as well as those that are unique to either species. She was also seeking duplications with a different number of copies in humans and chimps. Such duplications are thought to be a force for evolutionary change in genomes and are sometimes related to human diseases. Nature caught up with Cheng to find out more about her work.

How massive was this project?

It was big. I worked eight or nine hours a day on this for a year. I helped analyse around 100 gigabytes of data. For one table, I looked at 700 files. The project has been the dominant thing in my life for a year. It has been my life for a year.

What sort of challenges did you face?

We had a very heated lab meeting about the critical thresholds to detect recent duplications using data from two different species.

Why was this a challenge for you?

My background is in cell biology and molecular biology. Genomics research is very different. I had to read some papers to learn the concepts and to get used to what everybody was talking about.

What did the other members of the group do?

Evan Eichler came up with all the analysis for the paper and set out the way we should approach the topic. Eray Tuzun performed the analysis for duplication in the chimp genome assembly. Xinwei She did the gene-expression analysis of duplicate genes using data from our collaborator, Svante Pääbo.

Any critical points?

There was one day when I was very ill, but I had to finish what I was working on. I like my job, but it involves pressures. If you don't conquer those pressures, you don't accomplish anything.

How did you deal with the stress?

I jog to shed the pressure. When I get mentally exhausted, I want to be physically exhausted to relax.

How do you feel about the paper now?

I was not very clear of the big picture at the beginning. But when I look back, it is so beautiful.