Adaptation and Speciation
How predictable is evolution? Why does it arrive at the same ecological solutions over and over again? And why does it sometimes not? We investigate these questions in natural settings using as main model organisms the South American cichlids known locally as "Joanas" (Genus Crenicichla).
Using genomic data, we aim at reconstructing evolutionary history of populations and the traits that underlie their divergence. Using organismal methods (i.e. ecological, behavioral, morphometrics), we aim at describing the ecological significance of traits. Together, this allows testing hypotheses of how the evolutionary processes affect crucial traits (e.g. mate and habitat choice, adaptive function, evolutionary origin), giving rise to new species.
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We focus mainly on model-traits such as hypertorphic lips (a feeding adaptation) and pre-zygotic barriers in cichlid fishes. The Juanitas (Cichlidae: Crenicichla) are an exceptional system to test theoretical predictions of the genetic bases of adaptive radiations and ecological speciation.
Genome Evolution and Sex Determination in fishes
Genomes are invaluable tools that allow for the use of forward genetics and population genetics. We are currently focused on developing highly efficient approaches for obtaining chromosome-level reference genomes, pan genomes and population-based resequencing with long reads.
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To achieve this, we combine various sequencing platforms, tissue preservation methods and DNA purification methods. These range from a) genomic DNA, typically used for PCR-based and GBS methods; b) high molecular weight DNA, typically used for PacBio HiFi sequencing and c) ultra-high molecular weight DNA, used in Nanopore Ultralong Sequencing.
The differentiation of sex chromosomes has a great impact on genome evolution and can reveal the causes and consequences of variation in recombination rate. We combine genetic mapping in both experimental and natural populations with long-read sequencing to identify the causal genetic basis of sex determination, assemble and compare male and female genomes to test the general theory of sex chromosome evolution.
