Rxivist logo

Natural selection interacts with the local recombination rate to shape the evolution of hybrid genomes

By Molly Schumer, Chenling Xu, Daniel L. Powell, Arun Durvasula, Laurits Skov, Chris Holland, Sriram Sankararaman, Peter Andolfatto, Gil G Rosenthal, Molly Przeworski

Posted 01 Nov 2017
bioRxiv DOI: 10.1101/212407 (published DOI: 10.1126/science.aar3684)

While hybridization between species is increasingly appreciated to be a common occurrence, little is known about the forces that govern the subsequent evolution of hybrid genomes. We considered this question in three independent, naturally-occurring hybrid populations formed between swordtail fish species Xiphophorus birchmanni and X. malinche. To this end, we built a fine-scale genetic map and inferred patterns of local ancestry along the genomes of 690 individuals sampled from the three populations. In all three cases, we found hybrid ancestry to be more common in regions of high recombination and where there is linkage to fewer putative targets of selection. These same patterns are also apparent in a reanalysis of human-Neanderthal admixture. Our results lend support to models in which ancestry from the minor parental species persists only where it is rapidly uncoupled from alleles that are deleterious in hybrids, and show the retention of hybrid ancestry to be at least in part predictable from genomic features. Our analyses further indicate that in swordtail fish, the dominant source of selection on hybrids stems from deleterious combinations of epistatically-interacting alleles.

Download data

  • Downloaded 1,437 times
  • Download rankings, all-time:
    • Site-wide: 6,263 out of 88,995
    • In evolutionary biology: 306 out of 5,442
  • Year to date:
    • Site-wide: 53,335 out of 88,995
  • Since beginning of last month:
    • Site-wide: 76,713 out of 88,995

Altmetric data

Downloads over time

Distribution of downloads per paper, site-wide


Sign up for the Rxivist weekly newsletter! (Click here for more details.)