Exploring daily activity patterns, ecology, and genetics across hyperdiverse Lake Tanganyikan cichlids, Annika Nichols talk 21.07.2023


Annika is a postdoc in Alex Schier’s lab, Biozentrum, the University of Basel and studies the evolution of behaviour in African cichlids.

Many of the biological mechanisms that regulate the circadian phase, duration, and structure of diel activity are conserved across vertebrates. Given this extensive conservation, it is remarkable that activity patterns display widespread variation across species. However, the genetics and ecology underlying activity pattern diversity remain largely unknown.

Cichlids represent the most extraordinary example of vertebrate explosive speciation — in the Rift Valley Lakes of Africa ~2000 species have evolved within the last 10 million years. In these lakes, cichlids have diversified to inhabit a vast array of ecological niches; diversifying in diet, body shape, mating behaviours, colouration, and habitat preferences. However, little is known about how their behavioural and diel activity patterns relate to their explosive radiation. They have focused on a subset (>60) of the ~240 endemic Lake Tanganyikan cichlid species for which we have genomic, transcriptomic and ecological data. Using quantitative analysis of individual activity patterns over six days in the lab, they have found that cichlids occupy all temporal activity niches, including diurnal, crepuscular and nocturnal patterns. Using GWAS we have identified genetic associations with temporal activity, which is remarkably labile between species and across the phylogenetic tree. While there were some enrichments of temporal activity with diet across species (perhaps reflecting food availability), temporal activity does not have exclusive associations with trophic level, indicating temporal niche differentiation. Their results reveal previously unrecognised temporal diversity in cichlids, which may have contributed to their extensive diversification and evolutionary success.

She will also give an overview of a new research direction where she is leveraging the stereotypy and small nervous systems of Nematodes to functionally compare nervous systems across species

Date & time: 21.07.2023, 11:30
Location: Lecture Hall 2, University of Vienna UBB Building, Djerassiplatz 1