Biodiversity Butterfly invasion goes hand in hand with gene loss

The butterfly species karst white butterfly is spreading like an invasion throughout Europe. According to a new study by the University of Basel, this invasion has been accompanied by a major genetic loss within the species.

A large proportion of the original genetic material of the local populations has now been replaced by that of the population that has spread, the University of Basel announced on Wednesday. The individual Karstweisslings are therefore genetically much more similar than they were before the invasion began.

The researchers led by Daniel Berner from the University of Basel came to this conclusion by comparing today's Karstweisslings with museum specimens. The results were published in the journal "Current Biology".

Genetic diversity within a species is an important measure for experts, as species with greater genetic diversity are more resistant to disease, can adapt better to changing environmental conditions and therefore generally maintain more stable populations in the long term.

Spread since 2005

Thanks to the strong spread, karst white butterflies are much more numerous overall than before their invasion, which generally reduces their risk of extinction, according to the University of Basel.

Until a few years ago, there were only a few small local populations of the small white butterflies in Valais and Ticino. North of the Alps, it was hardly to be found. Since 2005, however, the species has been spreading rapidly.

As the species largely uses man-made habitats in the newly colonized area, competition with native butterflies is not to be expected, according to the university.

SDA