Evolutionary genetics of convergent mimicry colour patterns in bumble bees

• Applicant: Dr. Eckart Stolle
• Subject Area: Evolutionary Cell and Developmental Biology (Zoology) ; Evolution, Anthropology
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 433110898

Convergent evolution of complex phenotypes is one of the most striking and fascinating examples of adaptive evolution. Shaped by natural selection, unrelated organisms can converge on an surprising level and mimic each other in colour and shape, often to send the same aposematic signals to prevent predation (Müllerian mimicry). However, the molecular underpinning of these striking case of evolutionary convergence are not well understood. A group of important pollinators, bumblebees, have convergently evolved several colour patterns which are shared across unreleated bumblebee lineages. Strikingly, some polymorphic species show similar intraspecific colour pattern shifts parallel to other, unrelated sympatric bumblebee species. These species provide an excellent opportunity to study the genomic architecture of these adaptive phenotypic traits as well as their convergent evolution. Due to the enormous technological advances a broad comparative genomics approach combined with developmental genetics is now feasable and will provide comprehensive insights in the genetic mechanisms facilitating and regulating colour shifts in bumblebees, but also whether convergent shifts are underpinned by the same mechanisms, or stem from different molecular changes. I propose to investigate four independent shifts (four unrelated polymoprhic species) between the two predominant colour patterns in European bumblebee species (black-yellow-white to black-red) and include fascinating cases of intra-specific convergence and parallel colour shifts in host bumblebees and the associated social parasite. The proposed study will shed light on how genomic architecture leads to adaptive colour polymorphisms within and between species and is facilitated by genome structure, coding sequence differences or regulatory change. These novel insights will broadly relevant for adaptive evolution in many other organisms, especially insects in which some even show polymorphic colour variation mimicking bumblebees and thus represent cases of Batesian mimicry.

• DFG Programme: Research Grants