The gene, called miR-941, appears to have played a crucial role in human brain development and may shed light on how humans learned to use tools and language, the University of Edinburgh reported Wednesday.
The gene is the first carried by humans and not by apes that has been shown to have a specific function within the human body, the researchers said.
Unique to humans, miR-941 emerged between 6 and 1 million years ago and is highly active in two areas of the brain that control decision-making and language abilities, they said.
It emerged fully functional out of non-coding genetic material, previously termed "junk DNA," in a startlingly brief interval of evolutionary time, the researchers said.
"As a species, humans are wonderfully inventive -- we are socially and technologically evolving all the time," Edinburgh researcher Martin Taylor said. "But this research shows that we are innovating at a genetic level too.
"This new molecule sprang from nowhere at a time when our species was undergoing dramatic changes: living longer, walking upright, learning how to use tools and how to communicate. We're now hopeful that we will find more new genes that help show what makes us human."