The butterfly effect

The butterflies of the Åland Islands have taught ecologist Ilkka Hanski what a population needs to survive.

One of the defining moments in the life and career of ecologist, Academy Professor Ilkka Hanski occurred in the summer of 1964. The then eleven-year-old Hanski, a butterfly enthusiast, caught a butterfly that was thought to have gone extinct in Finland decades earlier.

“You can imagine what it felt like when University of Helsinki Professor Esko Suomalainen, whose research had focused on the extinction of this very variety of butterfly, sent me his publication on the topic,” Hanski reminisces.

“It was in German, and I didn't understand the language, but I was very impressed nevertheless."

Now Hanski is at the undisputed top of research on the survival prerequisites of populations. His authority in the field is such that his book Metapopulation Ecology was published by the Oxford University Press, and is now studied by students around the world. Hanski’s particular expertise lies in the field of metapopulation, i.e., establishing to what extent the environment can fragment, before it begins to affect the population’s likelihood for survival.

The international academic community has acknowledged his merits in a number of ways, including honorary fellowships in both the Royal Society and the National Academy of Sciences, and the Crafoord prize, the so-called “mini Nobel” bestowed by the Swedish Royal Academy of Sciences.

Butterflies have remained one of Hanski's main areas of interest over the decades.

“Not long ago it was thought that evolution progresses so slowly that it cannot normally be perceived in nature. However, the two decades of research we've conducted on the Åland Islands have proven that the population fluctuation and microevolution among the butterflies in the area influence each other.”

Hanski is one of the stars of the website which represents the University's most quoted researchers. The research fields of the other academics on the website include imaging brain activity, English as a lingua franca, national diseases and international law.