The long-term consequences of hybridization

Le 08 Septembre 2023
11h30 Hybrid - online and Salle Louis Thaler, bat 22 UM


Department of Genetics, University of Cambridge, UK

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When genetically distinct populations meet and mate, the outcome depends on whether their alleles mix well together. If new high fitness genotypes can be produced, the long-term outcome could be population fusion or adaptive introgression; but if the alleles are incompatible, the outcome might be loss of local adaptation, or reinforcement selection for increased isolation. One problem is that the long-term effects of hybridization seem difficult to predict from its short-term effects. For example, very high fitness F1 are often followed by very unfit F2. The uncertainty about long-term outcomes helps to explain debates in conservation biology about the value of hybrid populations, founded through multi-origin translocations; and debates among crop breeders about whether heterosis might be “fixed”, so that the yield benefits of F1 hybrids might be transferred to recombinant inbred lines. I will present some theoretical results, developed as part of CeMEB’s LabEx program, aiming to increase the long-term predictability of hybridization.


1. De Sanctis B, Schneemann H, Welch JJ (2023). How does the mode of evolutionary divergence affect reproductive isolation? Peer Community Journal 3:e6. 

2. Schneemann H, Munzur AD, Thompson KA, Welch JJ (2022). The diverse effects of phenotypic dominance on hybrid fitness. Evolution 76:2846-2863.  

3. Simon A, Bierne N, Welch JJ (2018). Coadapted genomes and selection on hybrids: Fisher's geometric model explains a variety of empirical patterns. Evolution Letters 22:472-498. 


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Alison Duncan (UMR ISEM) / Guillaume Martin (UMR ISEM)