Scientists Discover Evolutionary Leap 500 Million Years Ago
A team of scientists investigating the functions of the ancestors of genes has discovered two mutations that led to an evolutionary leap 500 million years ago.
The latest study, published in the Proceedings of the National Academy of Sciences, looked at the precursors of genes that play important roles in human reproduction, development and immunity. By re-creating the same DNA changes that occurred during those genes' ancient history, the team found two mutations which led to a hormonal revolution.
"Changes in just two letters of the genetic code in our deep evolutionary past caused a massive shift in the function of one protein and set in motion the evolution of our present-day hormonal and reproductive systems," said Joe Thornton, PhD, professor of human genetics and ecology & evolution at the University of Chicago. "If those two mutations had not happened, our bodies today would have to use different mechanisms to regulate pregnancy, libido, the response to stress, kidney function, inflammation, and the development of male and female characteristics at puberty," Thornton said.
The research team were able to narrow down the time range for this chance to a period about 500 million years ago, before the dawn of vertebrate animals on earth, effectively re-creating ancient molecular evolution in the laboratory!
The results show that new molecular function can evolve by sudden leaps in the genetic code rather than by many tiny steps. If such mutations had not occurred, we may not be the kind of human beings we are today.