Plant Study Hints Evolution May Be Predictable
Published:27 Jul.2022 Source:Yale University
For the study, the research team studied the genetics and morphology of the plant lineage Viburnum, a genus of flowering plants that began to spread south from Mexico into Central and South America some 10 million years ago. Donoghue studied this same plant group for his Ph.D. dissertation at Harvard 40 years ago. At the time, he argued in favor of an alternative theory in which large, hair-covered leaves and small smooth leaves evolved early in the evolution of the group and then both forms migrated separately, being dispersed by birds, through the various mountain ranges. The new genetic analyses reported in the paper, however, show that the two different leaf types evolved independently, in parallel, in each of a number of mountain regions.
"I came to the wrong conclusion because I lacked the relevant genomic data back in the 1970s," Donoghue said. The team found that a very similar set of leaf types evolved in nine of 11 regions studied. However, the full array of leaf types may have yet to evolve in places where Viburnum has only more recently migrated. For instance, the mountains of Bolivia lack the large hairy leaf types found in other wetter areas with little sunshine in the cloud forest in Mexico, Central America, and northern South America.