Biologists used to think that new genes “could only evolve from duplicated or rearranged versions of preexisting genes.” Now, though:

Scientists have made a crucial discovery of genes that have evolved in humans after branching off from other primates, opening new possibilities for understanding what makes us uniquely human….

Researchers have found genes that arose from non-coding DNA in flies, yeast, and primates. No such genes had been found to be unique to humans until now, and the discovery raises fascinating questions about how these genes might make us different from other primates….

The authors [David Knowles and Aoife McLysaght of the Smurfit Institute of Genetics at Trinity College Dublin] also note that because of the strict set of filters employed, only about 20% of human genes were amenable to analysis. Therefore they estimate there may be approximately 18 human-specific genes that have arisen from non-coding DNA during human evolution.

This discovery of novel protein-coding genes in humans is a significant finding, but raises a bigger question: What are the proteins encoded by these genes doing? “They are unlike any other human genes and have the potential to have a profound impact,” McLysaght noted. While these genes have not been characterized yet and their functions remain unknown, McLysaght added that it is tempting to speculate that human-specific genes are important for human-specific traits.

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