Urbanization-associated range expansion genetically homogenizes a butterfly species.

Human-induced environmental change and globalization facilitate biological invasions, which can lead to the displacement of native species by non-native ones. ^{1 , 2 , 3 , 4} Analogously, biodiversity loss may occur within species when habitat modifications facilitate the expansion of a specific population's range, leading to genetic admixture with native local populations. We demonstrate such intraspecific loss in population-level diversity in the Southern Small White (Pieris mannii), an originally sedentary butterfly ⁵ that recently expanded its range across Central Europe due to urbanization. ^{6 , 7 , 8} Using genome-wide markers from historical museum specimens and contemporary samples, we identify a distinct population initiating this expansion and reveal the genetic homogenization of native local populations by admixture with the expansive one. Our study illustrates how human-made environmental change can simultaneously benefit a species by permitting range expansion and drive cryptic biodiversity loss through the genetic homogenization of conspecific populations.
Competing Interests: Declaration of interests The authors declare no competing interests.
(Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)