She reveals relationships millions of years old

She was a success at the Researchers’ Grand Prix 2012 where she met a spikemoss for a cup of coffee. Stina Weststrand will soon be defending her thesis on the plant whose roots she has been tracing all round the world.
“By creating order in nature’s hordes we learn more about the evolution of life.” says the doctoral student in plant systematics.

Getting a bunch of high school students to cheer and applaud a scientific presentation is not an honour granted to many researchers. Stina Weststrand managed the feat, however, at the regional final of the 2012 Researchers’ Grand Prix in Uppsala. She captivated both the jury and the audience with tales of her creative hunt for the history of the spikemoss. The image of her phoning a spikemoss and arranging a date at a café is already plant history.

“I was just waiting for a little bell to ring, waiting for some kind of idea. But I didn’t get one. Why did I enter this thing?” says Stina Weststrand laughing.

“But then only a week or so before the event, the bell rang. I know what I’ll do. This is going to be fun.”

She won the Uppsala qualifier and went on to the national final at the Debaser rock club in Stockholm, where she came second. Her performances whetted her appetite and also made her start thinking about scientific communication as a possible choice of profession.

“This part of the research is great fun. A few months ago, I gave a popular science lecture at the newly opened SciCafé at Hamncentralen. The atmosphere was cosy and people were drinking their tea and coffee at the same time. It turned into a good q&a session. The questions were about everything from Linnaeus to what spikemosses can be used for.”

The spikemosses, mostly found in the tropics, are quite common as ornamental plants and are also used as medicinal plants. This plant group, which has the scientific name Selaginella and is actually not a moss but a lycophyte, caught her interest during her time taking the Biology option within the Natural Sciences programme at Uppsala University. By chance, she got into the course Evolution and Diversity of Plants in spring 2009. Her teacher, Petra Korall, was very encouraging and had herself produced a doctoral thesis on the subject of spikemosses.

“It may have been more because I liked Petra,” says Stina Weststrand, laughing. It was very enjoyable to systematise and group plants. And when I decided to go for a doctoral degree in plant systematics it was just my luck that Petra had funds for a doctoral project.”

Stina Weststrand has applied herself to examining how it is possible that spikemosses are found on every continent. Did this plant group spread by dispersal of their minute spores? Or did they hitch a lift on the continents when the super continent Pangea started to split up almost 200 million years ago? Stina hopes to find some clues in the materials she has collected from around the world.

“My first trip was to Ecuador in autumn 2010 when I started my doctoral studies. There are a whole heap of spikemosses there, most of them in the rain forest and in the cloud forest a little higher up. Then I’ve also been to Australia to collect plants in Queensland.”

Comparison of DNA from different organisms shows how closely related they are to each other. Stina Weststrand shows an evolutionary tree on her computer screen. It consists of a multitude of horizontal lines splitting off into sub-groups and continuing off into what seems like infinity.

“The ends of all the branches in the tree each represent a spikemoss. Where two branches meet is the point where they share a common ancestor. The principle is the same as when we construct family trees for our families.”

DNA technology and molecular studies have only been used in plant systematics for a little over 25 years. Before this, researchers mainly had to rely on morphological similarities between organisms, i.e. what they looked like. “Many of their conclusions, however, have been shown to be correct by DNA analyses,” says Stina Weststrand.

“There are, however, cases where DNA sequences say something different to the morphology and this gives rise to conflicts. You might then need to stir the pot and start to re-evaluate relationships. An organism might not belong at all to a certain group and may later have to be given a whole new name.”

Stina Weststrand herself has not been involved in renaming plants, but through her studies of spikemosses she has discovered previously unknown groupings. The research group led by Petra Korall will propose new ways to organise groups of spikemosses by applying the data they have collected.

“But we haven’t seen everything. There are probably lots of spikemosses unknown to science and which might disappear before we even find them.”

What is it that drives your research?

“There are a lot of questions about spikemosses which still need to be answered. Nobody, for example, has previously done research into how they have spread round the world. I enjoy being one of the people filling in more pieces of the puzzle of the evolution of life,” says Stina Weststrand.

“When you consider that all life has a common ancestor, a common origin, then everything is connected to everything else. Plant systematics contributes towards the overall picture.”

Anneli Björkman