Behavioural evolution in the Tanganyikan cichlid adaptive radiation
- Datum: 11.03.2025
- Uhrzeit: 11:00 - 12:00
- Vortragende(r): Alex Jordan
- Max Planck Institute of Animal Behavior, Konstanz
- Ort: MPI BI Martinsried
- Raum: MPIBI, Seminar room NQ 105
- Gastgeber: Peter Jägers
- Kontakt: peter.jaegers@bi.mpg.de

Understanding how behaviour evolves presents a major challenge in biology – in particular how complex behavioural phenotypes may evolve from more simple ancestral states. Novel behaviours may arise in various ways; i) existing behavioural repertoires may be augmented by de novo development of behavioural elements; ii) changes in the sequence or frequency of existing elements that retain their original function but may produce a different outcome; or iii) behavioural exaptation may occur, in which existing behavioural elements are modified to suit a novel purpose. In this talk I will explore these different evolutionary pathways by discussing our work in the explosive adaptive radiation of Lake Tanganyikan cichlids. Using automated postural tracking, behavioural decomposition, and 3D scene reconstruction in natural underwater environments, we quantify and compare the behaviour of animals in relevant ecological settings. We use this data to create comprehensive behavioural phenomes for each extant species, allowing us to reconstruct ancestral behavioural states and interrogate processes of behavioural evolution across the Tanganyikan cichlid lineage. We find that despite variation in social organisation, ecology, and evolutionary history, kinematic elements of behaviour are highly conserved within this lineage (i.e. no new forms of behaviour have evolved). However, species use this common structural repertoire in specific ways, employing elements in divergent combinations, relative orientations, and frequencies. In ongoing work, we examine how these shared forms have taken on novel functions across lineages by using digital avatar playbacks. In these experiments, we express various behavioural phenotypes in familiar conspecific avatars, including heterospecific behaviours, ancestral behaviours, and even currently non-existent areas of behavioural space. These playbacks allow us to explore the interaction among behavioural form and function across an evolutionary lineage.