THE STORY TOLD BY FOSSIL PLANTS
By Edward Wilber Berry
Professor of Palaeontology, The Johns Hopkins University
Students of evolution are at present interested almost exclusively in experimental studies that may disclose its causes, an extremely difficult problem even with the simplest and most rapidly multiplying organisms. Such studies, however, afford the only logical approach to an answer to the question “Why?” The answer to the question “How?” is given best in the geological record. Paleobotany—the science of the world’s oldest plant life—has this advantage over all other methods of finding an answer to this question: the student, to borrow a simile from written history, is dealing with the original documents in so far as they are preserved—the fossil plants—and he finds them in their actual order of succession. Our main task here, then, is simply to tell the story of the procession of the myriad of plant forms across the stage of the past. Before that story is told, however, the general facts and principles illustrated by fossil plants may be very briefly set forth.
First among these is the fact that plants underwent a gradual transformation from simplicity to complexity and were differentiated in both structure and habit in successively higher groups, thus exemplifying the universal principle of evolution. The earliest plants grew in the water, but gradually the main theater of plant operations was transferred to the land.
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