Winters restrict a climate change–driven butterfly range expansion despite rapid evolution of seasonal timing traits
(2025) In Proceedings of the National Academy of Sciences of the United States of America 122(26).- Abstract
Climate change pushes species toward higher latitudes and altitudes, but the proximate drivers of range expansions vary, and it is unclear whether evolution facilitates climate change–induced range changes. In a temporally replicated field experiment, we trans-located wall brown butterflies (Lasiommata megera) descending from range interior and range margin populations to sites at 1) the range interior, 2) the range margin, and 3) beyond the current northern range edge. Thereby, we tested for local adaptation in seasonal timing and winter survival and evaluated to what extent local adaptation influences the ongoing, climate-driven range expansion. Almost all individuals from all populations entered diapause at an appropriate time,... (More)
Climate change pushes species toward higher latitudes and altitudes, but the proximate drivers of range expansions vary, and it is unclear whether evolution facilitates climate change–induced range changes. In a temporally replicated field experiment, we trans-located wall brown butterflies (Lasiommata megera) descending from range interior and range margin populations to sites at 1) the range interior, 2) the range margin, and 3) beyond the current northern range edge. Thereby, we tested for local adaptation in seasonal timing and winter survival and evaluated to what extent local adaptation influences the ongoing, climate-driven range expansion. Almost all individuals from all populations entered diapause at an appropriate time, despite previously identified among-population variation in diapause induction thresholds. Caterpillars of northern descent, however, grew faster than those from southern populations at all field sites. This may be a countergradient adaptation to compensate for the short, northern growing seasons, but we found no evidence for prewinter body mass affecting winter survival. In fact, winter survival was low overall—extremely so at the beyond range site—regardless of population origin, indicating that the primary constraint to range expansion is an inability to adapt to winter conditions. Hence, although range-expanding wall browns show clear local evolution of two traits related to seasonal timing, these putative local adaptations likely do not contribute to range expansion, which is instead limited by winter survival. To predict future range changes, it will be important to distinguish between the traits that evolve during range expansion and those that set the range limit.
(Less)
- author
- Ittonen, Mats ; Nielsen, Matthew E. ; Siemers, Isabelle ; Friberg, Magne LU and Gotthard, Karl
- organization
- publishing date
- 2025-07-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- diapause, growth rate, life history, local adaptation, transplant experiment
- in
- Proceedings of the National Academy of Sciences of the United States of America
- volume
- 122
- issue
- 26
- article number
- e2418392122
- publisher
- National Academy of Sciences
- external identifiers
-
- pmid:40549916
- scopus:105009578849
- ISSN
- 0027-8424
- DOI
- 10.1073/pnas.2418392122
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: Copyright © 2025 the Author(s).
- id
- 5fc3a146-5c4c-4d92-bc42-2a11d0fa4e5f
- date added to LUP
- 2025-12-09 14:41:18
- date last changed
- 2025-12-09 14:43:03
@article{5fc3a146-5c4c-4d92-bc42-2a11d0fa4e5f,
abstract = {{<p>Climate change pushes species toward higher latitudes and altitudes, but the proximate drivers of range expansions vary, and it is unclear whether evolution facilitates climate change–induced range changes. In a temporally replicated field experiment, we trans-located wall brown butterflies (Lasiommata megera) descending from range interior and range margin populations to sites at 1) the range interior, 2) the range margin, and 3) beyond the current northern range edge. Thereby, we tested for local adaptation in seasonal timing and winter survival and evaluated to what extent local adaptation influences the ongoing, climate-driven range expansion. Almost all individuals from all populations entered diapause at an appropriate time, despite previously identified among-population variation in diapause induction thresholds. Caterpillars of northern descent, however, grew faster than those from southern populations at all field sites. This may be a countergradient adaptation to compensate for the short, northern growing seasons, but we found no evidence for prewinter body mass affecting winter survival. In fact, winter survival was low overall—extremely so at the beyond range site—regardless of population origin, indicating that the primary constraint to range expansion is an inability to adapt to winter conditions. Hence, although range-expanding wall browns show clear local evolution of two traits related to seasonal timing, these putative local adaptations likely do not contribute to range expansion, which is instead limited by winter survival. To predict future range changes, it will be important to distinguish between the traits that evolve during range expansion and those that set the range limit.</p>}},
author = {{Ittonen, Mats and Nielsen, Matthew E. and Siemers, Isabelle and Friberg, Magne and Gotthard, Karl}},
issn = {{0027-8424}},
keywords = {{diapause; growth rate; life history; local adaptation; transplant experiment}},
language = {{eng}},
month = {{07}},
number = {{26}},
publisher = {{National Academy of Sciences}},
series = {{Proceedings of the National Academy of Sciences of the United States of America}},
title = {{Winters restrict a climate change–driven butterfly range expansion despite rapid evolution of seasonal timing traits}},
url = {{http://dx.doi.org/10.1073/pnas.2418392122}},
doi = {{10.1073/pnas.2418392122}},
volume = {{122}},
year = {{2025}},
}