Tanja Pyhäjärvi studies the evolutionary and population genomics of plants, with special focus on forest tree species. She has always found evolution the most fascinating phenomenon on Earth. She is also interested in the molecular details of evolution.
“What happens at the genetic level to produce the biodiversity we see at the phenotypic level? What in the DNA and genome makes species, populations and individuals different from each other?”, she asks.
She finds forest trees a suitable object of study for her.
“Trees are masters of adaptation, they have often complex genomes and there are lots of them at the high latitudes of Finland. They are also very beautiful!”
Forest genomics is moving from being technology-limited to being “question-limited”. This is thanks to the development of genomic technology such as DNA sequencing and genome editing, and also the rapid development of computing power and statistical methods in the past two decades.
“This is the perfect time to find answers to genetics- and evolution-related questions that were out of our reach before,” says Pyhäjärvi.
Pyhäjärvi’s research group’s work answers questions about how organisms adapt to, for example, the cold, long winters of the north or the hot, dry summers of the south, or how breeding and different management choices affect genetic diversity.
“I think it is part of natural human curiosity and drive to understand the world we see around us and what is behind the magnificent adaptations and biological diversity at the molecular level,” Pyhäjärvi says.
Ongoing research projects
Her research group studies the genetics and evolution of forest tree species from multiple angles. At the moment, a big national collaborative project investigates the role of gene expression regulation and chromatin accessibility in the evolution of the environmental adaptation of the Scots pine (Pinus sylvestris) and silver birch (Betula pendula).
Another project, together with scientists from Uppsala University and INRAE (France), among others, studies what kind of signatures past environmental and demographic changes have left in the genomes of forest trees.
From a very “classical” evolutionary genetic point of view, Tanja Pyhäjärvi is also really fascinated by the conifer reproductive system that is very different to broadleaf and flowering plant systems, and she has developed a model to study its evolution with Professor Brandvain of the University of Minnesota.
In addition, as part of the B4EST and FORGENIUS H2020 projects, she and her researchers are developing genomic resources for forest tree breeding and more accessible genetic knowledge for the conservation and management of forest genetic resources.
“Forests are a major factor in the Finnish environment, economy and society. We should understand how our actions have affected and may affect the genetic diversity and potential for future adaptation of forests,” Pyhäjärvi concludes.
The Thriving Nature project strengthens the University of Helsinki’s profile in research into biological resilience. This project, a collaborative effort by the Faculty of Biological and Environmental Sciences, the Faculty of Agriculture and Forestry, and HiLife, will combine our expertise in ecology, evolutionary biology, genome-level processes and biotechnology by employing big data in an innovative way. The project is funded by the Academy of Finland.