How Do Species Originate?
Laureate: Dolph Schluter (University of British Columbia)
About This Prize
The 2023 Crafoord Prize in Biosciences was awarded to Dolph Schluter (University of British Columbia, Canada) “for fundamental contributions to the understanding of adaptive radiation and ecological speciation.” Schluter's decades of research on threespine stickleback fish in post-glacial lakes of British Columbia provided some of the most compelling evidence that natural selection is the primary driver of speciation. His work demonstrated that species pairs arise repeatedly when populations adapt to different ecological niches, establishing ecological speciation as a major mode of species formation.
★ Laureate Lecture
Dolph Schluter
University of British Columbia, Canada
“The Evolution of Phenotypic Incompatibilities During Speciation”
Schluter presents his research on how divergent natural selection leads to the evolution of phenotypic trait differences that cause reproductive isolation — demonstrating that ecological adaptation itself generates incompatibilities between nascent species.
◆ Invited Lectures
Catherine Peichel
University of Bern, Switzerland
“Genetics and the Origin of Stickleback Species”
Peichel explores the genetic architecture underlying species differences in stickleback fish, identifying the specific genes and genomic regions responsible for adaptive traits like armor plating, body shape, and pigmentation.
Andrew MacColl
University of Nottingham, UK
“Parallelism and Persistence During Stickleback Divergence”
MacColl examines repeated patterns of phenotypic divergence across independent stickleback populations, investigating the extent to which parallel evolution is predictable and whether divergent forms persist over evolutionary time.
Kerstin Johannesson
University of Gothenburg, Sweden
“Parallel Speciation and the Role of Chromosomal Rearrangements”
Johannesson presents research on Littorina snails showing how chromosomal inversions suppress recombination and protect co-adapted gene complexes, facilitating parallel speciation across multiple coastal populations.
Daniel Ortiz-Barrientos
University of Queensland, Australia
“The Causes and Consequences of Parallel Speciation in Plants”
Ortiz-Barrientos discusses parallel speciation in Australian Senecio wildflowers, demonstrating how repeated adaptation to different soil types drives convergent reproductive barriers through shared and distinct genetic mechanisms.
Hanna Johannesson
The Royal Swedish Academy of Sciences, Sweden
“Mate First, Ask Questions Later: On the Process of Speciation in the Fungi”
Johannesson explores speciation processes in Neurospora fungi, where prezygotic barriers are weak and postzygotic incompatibilities evolve gradually, offering a unique perspective on how reproductive isolation develops in organisms with different mating systems.
Anna Runemark
Lund University, Sweden
“Hybrid Speciation and Genome Stabilization in Passer Sparrows”
Runemark presents evidence for hybrid speciation in Italian sparrows, showing how hybridization between house sparrows and Spanish sparrows generated a stabilized hybrid lineage with a mosaic genome and novel phenotypic combinations.
Key Concepts
- • Ecological Speciation: The process by which divergent natural selection between environments leads to reproductive isolation as a byproduct of ecological adaptation
- • Adaptive Radiation: Rapid diversification from a common ancestor into multiple species, each adapted to different ecological niches — exemplified by Darwin's finches and stickleback fish
- • Parallel Speciation: Independent evolution of reproductive isolation between ecologically similar populations in different geographic locations, providing strong evidence for natural selection driving speciation
- • Phenotypic Incompatibility: Mismatches in ecologically adapted traits (morphology, behavior, physiology) that reduce fitness of hybrids or prevent successful mating between divergent populations
- • Chromosomal Rearrangements: Inversions and other structural changes that suppress recombination, protecting co-adapted gene complexes and facilitating divergence in the face of gene flow
- • Hybrid Speciation: Formation of a new species through hybridization between two existing species, where the hybrid lineage becomes reproductively isolated from both parents
- • Reproductive Isolation: The suite of barriers (prezygotic and postzygotic) that prevent gene flow between populations, ultimately defining species boundaries