USU biology professor traces ancestry of plants
The way people feel about the potted ferns in their apartments may change, thanks to a new hypothesis presented by a professor at Utah State University and a group of scientists across the nation last month about the genealogy of plants.
Paul Wolf, an associate professor in the Biology department at USU who was involved in the project, said there could possibly be an error in the way most textbooks describe the evolution or genealogy of plants.
Wolf said the old tradition believed plants evolved from simple to complex and that it was linear.
That traditional belief observed that algae evolved to mosses, mosses to ferns, ferns to seed plants and finally seed plants to flowering plants, which have appeared to dominate the planet for the last 90 million years.
Wolf and his colleagues’ research makes grounds for a new hypothesis. Wolf said there might have been a break in the linear evolution of plants very early on. He said plants may have been on Earth for about 450 million years.
The break would have occurred about 400 million years ago.
According to the new hypothesis, ferns and other plants broke off from seed plants and flowering plants and made their own evolution from there.
Wolf said the problem with charting a plant family tree is that the process is difficult. Wolf said humans can go to the Church of Jesus Christ of Latter-day Saints Family History Library in Salt Lake City and look up their ancestors without too much trouble.
“It’s very easy to find out who your parents are. It’s very easy to find out who your grandparents are. But the farther back in time you go the more difficult it is. Sometimes you go down the wrong pathway. You make mistakes and you correct them,” Wolf said.
Because of the old tradition, many people have considered plants like ferns as primitive, simple and of a lower class of plants, Wolf said.
“It’s not lower down on any scale,” Wolf said.
He said the linear view of evolution is often flawed. He said all organisms right now are basically equally developed as far as evolution is concerned.
“Nothing’s really getting better and better and better. The truth is they’re just adapting or they’ll go extinct. Everything we have now is off the tip of the tree,” Wolf said.
It took Wolf working with his former graduate student, Sedonia Sipes, and colleagues from the Field Museum in Chicago and the University of California at Berkeley about four years to gather and process all the data required by the project.
They compiled DNA sequences from genes that all plants have, like photosynthesis genes. They could then compare the differences between plant genes and attempt to trace their ancestry.
“As usual, you end up with more questions than answers,” Wolf said.
Wolf said he’s going to ask for another grant to start gathering more complete DNA sequences to form a picture with a clearer “resolution” of plant genealogy.
He said right now it’s possible to gather the complete information, but computers would have a very hard time crunching all the numbers.