• Article
    | Open Access

    Without understanding the genetic architecture of inbreeding depression, its effects are hard to pinpoint. Long-term data from wild Soay sheep shows that inbreeding manifests in long runs of homozygosity, which made up nearly half of the genome in the most inbred individuals with severe fitness consequences.

    • M. A. Stoffel
    • , S. E. Johnston
    •  & J. M. Pemberton
  • Article
    | Open Access

    Highly endangered species like the Sumatran rhinoceros are at risk from inbreeding. Five historical and 16 modern genomes from across the species range show mutational load, but little evidence for local adaptation, suggesting that future inbreeding depression could be mitigated by assisted gene flow among populations.

    • Johanna von Seth
    • , Nicolas Dussex
    •  & Love Dalén
  • Article
    | Open Access

    Inbreeding depression has been observed in many different species, but in humans a systematic analysis has been difficult so far. Here, analysing more than 1.3 million individuals, the authors show that a genomic inbreeding coefficient (FROH) is associated with disadvantageous outcomes in 32 out of 100 traits tested.

    • David W Clark
    • , Yukinori Okada
    •  & James F Wilson
  • Article
    | Open Access

    Mating between first or second-degree relatives is prohibited in most countries, yet it occurs and is under-studied. Here, Yengo et al. use large runs of homozygosity from the UK Biobank resource to provide DNA-based quantification of extreme inbreeding and its consequence for health and other complex traits.

    • Loic Yengo
    • , Naomi R. Wray
    •  & Peter M. Visscher
  • Article |

    Inbreeding reduces the fitness of birds and mammals, but at which stage in development this occurs is not always clear. Hemmingset al. show that when closely related zebra finches breed together, fertilisation proceeds normally, but the offspring are more likely to die during development of the embryo.

    • N.L. Hemmings
    • , J. Slate
    •  & T.R. Birkhead
  • Article |

    Migratory segregation presents a hypothesized barrier to gene flow among seabirds, but its mechanisms are unclear. Rayneret al. find that migratory habitat specialization, associated with breeding asynchrony and philopatry, restricts gene flow between two seabird populations migrating across the Pacific Ocean.

    • Matt J. Rayner
    • , Mark E. Hauber
    •  & Scott A. Shaffer