New genes are as essential for life as ancient ones: Study

A study has revealed that new genes that have evolved in species as little as one million years ago can be just as essential for life as ancient genes.

Evolutionary biologists have long proposed that the genes most important to life are ancient and conserved, handed down from species to species as the "bread and butter" of biology.

New genes that arise as species split off from their ancestors were thought to serve less critical roles - the "vinegar" that adds flavour to the core genes.

But when nearly 200 new genes in the fruit fly species Drosophila melanogaster were individually silenced in laboratory experiments at the University of Chicago, more than 30% of the knockdowns were found to kill the fly.

The study suggests that new genes are equally important for the successful development and survival of an organism as older genes.

Of the 195 young genes tested, 59 were lethal, causing the fly to die during its development. When the same method was applied to a sample of older genes, a statistically similar figure was found: 86 of 245 genes were lethal when silenced.

Because the young genes tested only appeared between one and 35 million years ago, the data suggests that new genes with new functions can become an essential part of a species' biology much faster than previously thought.

The study appeared in the December 17 issue of Science.