This study helps to explain how one person's face can look so different from another's. Scientists have identified thousands of sequences in our DNA that influence our appearance as we develop in the womb.
By looking at mice, they found that removing some of this genetic material subtly altered the rodent's appearance. In some, the modified DNA led to a longer or shorter skull, while others had wider or narrower faces. The researchers say that although the work was carried out on animals, the human face is likely to develop in the same way.
Dr Axel Visel, from the Lawrence Berkely National Laboratory in California led the study.
"We are trying to find out how the instructions for building the human face are embedded in the human DNA, so somewhere in there, there must be that blueprint that defines what our face looks like."
The researchers say understanding this complex process could also help to reveal how facial birth defects - such as cleft lips and palates - arise.
recognised
made very small changes to
performed, did
combined with, made part of
full and detailed plan
abnormalities that people are born with