A number of stories this year touched on the theme of using DNA to look backward. That’s because a species’ evolutionary history is written in its As, Cs, Ts, and Gs—the challenge is developing the technology and computing power necessary to read that story. Recent advances in both have opened many new avenues of genomic research, including the ability to detect lingering DNA from ancient hybridizations. In many cases, the sequences’ donors remain shrouded by history, with only scattered genetic segments revealing their existence. Still, these genomic ‘ghosts’ are “like another way of looking into the fossil record,” said Beth Shapiro, an evolutionary biologist at the University of California, Santa Cruz. And they’re helping scientists understand how species interacted in the past, how they adapted to novel or changing environments, what makes them unique today, and even how humans might introduce changes we want in the future.
As sequencing has ...
