Abstracts (first author)

Talk 

The evolution of alternative developmental pathways in a butterfly: local adaptation in developmental thresholds and footprints of relaxed selection on life history plasticity

Author(s): Gotthard K

Summary:

The ability of many temperate insects to have more than one generation per year is due to the plastic induction of alternative developmental pathways - leading to either direct development during summer or diapause development during winter. Typically, the number of generations produced within a population decrease with increasing latitude and the developmental threshold determining which pathway to follow is predicted to show a latitudinal cline due to local adaptation to season length. Consequently, when moving north along a latitudinal cline, populations will ultimately become univoltine and only produce one generation per year, which always enter diapause development. In such locations where only the diapause developmental pathway is expressed, selection on developmental regulation of the direct pathway will be relaxed. I will present results showing how the photoperiodic threshold determining the pathway decision in the butterfly Pararge aegeria is locally adapted to season length. Moreover, I will explore footprints of relaxed selection on the developmental regulation of life history traits and sexual dimorphism when expressed in the direct development pathway. The results suggest that populations experiencing relaxed selection on the direct pathway show less pronounced differences between pathways in several life history phenotypes. In particular, relaxed selection on direct development was associated with a disruption of protandry (earlier emergence of adult males) expressed as sexual dimorphism in larval development time and growth rate. This suggests that relaxed selection on the direct pathway has allowed life history traits to drift towards trait values associated with lower fitness, and that ongoing selection is necessary for upholding this type of “fine tuning” of alternative developmental regulation.


Video


Abstracts (coauthor)

Summary:

Variation in environmental suitability for growth and reproduction throughout the year at temperate latitudes has given rise to intricate adaptations in the timing of life history events of flora and fauna in order to keep the life cycle in phase with the changing season. Phenological traits are often important for fitness, as they affect the biotic and abiotic environment an individual encounters and can vary geographically because of local adaptation as well as via phenotypic plasticity. Disentangling environmental effects (phenotypic plasticity) and genetic effects (local adaptation, genetic drift) behind phenotypic geographic variation of a species may aid in predicting ecological responses to changing environments. The spatiotemporal pattern of covariation of phenology and temperature in the orange tip, Anthocharis cardamines, was studied in order to partition the contribution of local adaptation and phenotypic plasticity to the specific traits. The butterfly shows geographic variation in its relation of phenology to temperature variation in the United Kingdom as well as in Sweden. This discrepancy in population differentiation may be driven by host plant phenology and availability, emphasizing the ecological importance of the temporal aspects of host plant-herbivore interactions.

Contacts

Chairman: Octávio S. Paulo
Tel: 00 351 217500614 direct
Tel: 00 351 217500000 ext22359
Fax: 00 351 217500028
email: mail@eseb2013.com

Address

XIV Congress of the European Society for Evolutionary Biology

Organization Team
Department of Animal Biology (DBA)
Faculty of Sciences of the University of Lisbon
P-1749-016 Lisbon
Portugal

Website

Computational Biology & Population Genomics Group 
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