The evolutionary forces shaping life history divergence within species are largely unknown. Turquoise killifish display differences in lifespan among wild populations, representing an ideal natural experiment in evolution and diversification of life history. By combining genome sequencing and population genetics, we investigate the evolutionary forces shaping lifespan among wild turquoise killifish populations. We generate an improved reference genome assembly and identify genes under positive and purifying selection, as well as those evolving neutrally. Short-lived populations from the outer margin of the species range have small population size and accumulate deleterious mutations in genes significantly enriched in the WNT signaling pathway, neurodegeneration, cancer and the mTOR pathway. We propose that limited population size due to habitat fragmentation and repeated population bottlenecks, by increasing the genome-wide mutation load, exacerbates the effects of mutation accumulation and cumulatively contribute to the short adult lifespan.

• Keywords
• aging, evolution, evolutionary biology, genetics, genomics, lifespan, nothobranchius furzeri, turquoise killifish,
• MeSH
• Mutation Accumulation * MeSH
• Biological Evolution MeSH
• Longevity genetics   MeSH
• Ecosystem MeSH
• Fundulidae MeSH
• Genome genetics   MeSH
• Population Density * MeSH
• Models, Animal MeSH
• Evolution, Molecular * MeSH
• Aging genetics   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH

The turquoise killifish, Nothobranchius furzeri, is a promising vertebrate model in ageing research and an emerging model organism in genomics, regenerative medicine, developmental biology and ecotoxicology. Its lifestyle is adapted to the ephemeral nature of shallow pools on the African savannah. Its rapid and short active life commences when rains fill the pool: fish hatch, grow rapidly and mature in as few as two weeks, and then reproduce daily until the pool dries out. Its embryos then become inactive, encased in the dry sediment and protected from the harsh environment until the rains return. This invertebrate-like life cycle (short active phase and long developmental arrest) combined with a vertebrate body plan provide the ideal attributes for a laboratory animal.

• Keywords
• Ageing, Natural History, Nothobranchius furzeri, Senescence, The Natural History of Model Organisms, Turquoise killifish, ecology, evolutionary biology,
• MeSH
• Cyprinodontiformes genetics   growth & development   physiology   MeSH
• Diet MeSH
• Ecosystem * MeSH
• Embryo, Nonmammalian physiology   MeSH
• Models, Animal MeSH
• Pigmentation MeSH
• Sexual Behavior, Animal MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH