Evolutionary Stasis

Haeckel_Filicinae_92Last month, a team of scientists announced that they had analyzed an “exquisitely preserved” fossilized fern that was more than 180 million years old. They analyzed the calcified fern’s particularly well-preserved stem using a variety of microscopic instruments, and the detail they found was incredible. Every aspect of the fern’s cells had been preserved in nearly mint condition, and the scientists were able to observe ultra-fine structures within the nuclei. They also observed ancient chromosomes caught in the act of splitting, and they obtained 3-dimensional scans of ancient organelles. Their study is obviously a triumph of ever-improving technology, but it also reveals something more. We live on an incredibly dynamic planet where the environment changes from minute to minute, and from epoch to epoch, yet ferns have not evolved in any discernible way for the past 180 million years. According to scientists, this represents a “paramount case of evolutionary stasis.” To learn more about this topic, you can check out the scientists’ paper at this link. While you’re at it, check out Ernst Haeckel‘s awesome illustration of ferns (1904) at this link.