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  • 1.
    Hughes, P. William
    Max Planck Institute for Plant Breeding Research, Germany.
    After the genome rush: Postgenomics: Perspectives on Biology After the Genome Sarah S. Richardson and Hallam Stevens, Eds. Duke University Press, 2015. 304 pp.2015Inngår i: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 349, nr 6247, s. 483-484Artikkel, omtale (Annet vitenskapelig)
  • 2.
    Hughes, P. William
    Carleton University, Canada.
    Are Species Special?: The Ethics of Species An Introduction by Ronald L. Sandler Cambridge University Press, Cambridge, 20122013Inngår i: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 339, nr 6123, s. 1035-1035Artikkel, omtale (Annet vitenskapelig)
  • 3.
    Hughes, P. William
    Max Planck Institute for Plant Breeding Research, Germany; University of Cologne, Germany.
    How universal is the evolution of senescence?2017Inngår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 71, nr 7, s. 1919-1921Artikkel i tidsskrift (Fagfellevurdert)
  • 4.
    Hughes, P. William
    Max Planck Institute for Plant Breeding Research, Germany; University of Cologne, Germany.
    Minimal-Risk Seed Heteromorphism: Proportions of Seed Morphs for Optimal Risk-Averse Heteromorphic Strategies2018Inngår i: Frontiers in Plant Science, ISSN 1664-462X, E-ISSN 1664-462X, Vol. 9, artikkel-id 1412Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Seed heteromorphism is the reproductive strategy characterized by the simultaneous production of multiple seed types. While comparing heteromorphic to monomorphic strategies is mathematically simple, there is no explicit test for assessing which ratio of seed morphs minimizes fitness variance, and hence offers a basis for comparing different heteromorphic strategies. Such a test may be particularly valuable when more than two distinct morphs are present, since many strategies may have equivalent geometric fitnesses. As noted by Gillespie (1974), in these cases avoiding rare but evolutionarily important instances of severe reductions in fitness involves the minimization of variation in fitness—i.e., risk. Here I compute the optimal proportions of two or more seed morphs for heteromorphic strategies that either: (1) minimize total fitness variance; or (2) maximize the fitness-risk ratio—i.e., the “extra” fitness accrued per unit of “extra” fitness variance. This work thereby provides a testable null hypothesis to estimate the optimal frequencies of seed morphs when multiple heteromorphic strategies have evolved in environments with severe fitness risks. Moreover, it also permits the calculation of expected seed morph frequencies when more than two seed morphs are produced.

  • 5.
    Hughes, P. William
    et al.
    Max Planck Institute for Plant Breeding Research, Germany.
    Simons, Andrew M.
    Microsatellite evidence for obligate autogamy, but abundant genetic variation in the herbaceous monocarp Lobelia inflata (Campanulaceae)2015Inngår i: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 28, nr 11, s. 2068-2077Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Although high levels of self‐fertilization (>85%) are not uncommon in nature, organisms reproducing entirely through selfing are extremely rare. Predominant selfers are expected to have low genetic diversity because genetic variation is distributed among rather than within lineages and is readily lost through genetic drift. We examined genetic diversity at 22 microsatellite loci in 105 individuals from a population of the semelparous herb Lobelia inflata L. and found (i) no evidence of heterozygosity through outcrossing, yet (ii) high rates of genetic polymorphism (2–4 alleles per locus). Furthermore, this genetic variation among lineages was associated with phenotypic traits (e.g. flower colour, size at first flower). Coupled with previous work characterizing the fitness consequences of reproductive timing, our results suggest that temporal genotype‐by‐environment interaction may maintain genetic variation and, because genetic variation occurs only among lineages, this simple system offers a unique opportunity for future tests of this mechanism.

  • 6.
    Hughes, Patrick William
    Max Planck Institute for Plant Breeding Research, Germany.
    Between semelparity and iteroparity: Empirical evidence for a continuum of modes of parity2017Inngår i: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 7, nr 20, s. 8232-8261Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The number of times an organism reproduces (i.e., its mode of parity) is a fundamental life‐history character, and evolutionary and ecological models that compare the relative fitnesses of different modes of parity are common in life‐history theory and theoretical biology. Despite the success of mathematical models designed to compare intrinsic rates of increase (i.e., density‐independent growth rates) between annual‐semelparous and perennial‐iteroparous reproductive schedules, there is widespread evidence that variation in reproductive allocation among semelparous and iteroparous organisms alike is continuous. This study reviews the ecological and molecular evidence for the continuity and plasticity of modes of parity—that is, the idea that annual‐semelparous and perennial‐iteroparous life histories are better understood as endpoints along a continuum of possible strategies. I conclude that parity should be understood as a continuum of different modes of parity, which differ by the degree to which they disperse or concentrate reproductive effort in time. I further argue that there are three main implications of this conclusion: (1) that seasonality should not be conflated with parity; (2) that mathematical models purporting to explain the general evolution of semelparous life histories from iteroparous ones (or vice versa) should not assume that organisms can only display either an annual‐semelparous life history or a perennial‐iteroparous one; and (3) that evolutionary ecologists should base explanations of how different life‐history strategies evolve on the physiological or molecular basis of traits underlying different modes of parity.

  • 7.
    Hughes, Patrick William
    et al.
    Max Planck Institute for Plant Breeding Research, Germany; University of Cologne, Germany.
    Soppe, Wim J. J.
    Albani, Maria C.
    Seed traits are pleiotropically regulated by the flowering time gene PERPETUAL FLOWERING 1 (PEP1) in the perennial Arabis alpina2019Inngår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 28, nr 5, s. 1183-1201Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The life cycles of plants are characterized by two major life history transitions—germination and the initiation of flowering—the timing of which are important determinants of fitness. Unlike annuals, which make the transition from the vegetative to reproductive phase only once, perennials iterate reproduction in successive years. The floral repressor PERPETUAL FLOWERING 1 (PEP1), an ortholog of FLOWERING LOCUS C, in the alpine perennial Arabis alpina ensures the continuation of vegetative growth after flowering and thereby restricts the duration of the flowering episode. We performed greenhouse and garden experiments to compare flowering phenology, fecundity and seed traits between A. alpina accessions that have a functional PEP1 allele and flower seasonally and pep1 mutants and accessions that carry lesions in PEP1 and flower perpetually. In the garden, perpetual genotypes flower asynchronously and show higher winter mortality than seasonal ones. PEP1 also pleiotropically regulates seed dormancy and longevity in a way that is functionally divergent from FLC. Seeds from perpetual genotypes have shallow dormancy and reduced longevity regardless of whether they after‐ripened in plants grown in the greenhouse or in the experimental garden. These results suggest that perpetual genotypes have higher mortality during winter but compensate by showing higher seedling establishment. Differences in seed traits between seasonal and perpetual genotypes are also coupled with differences in hormone sensitivity and expression of genes involved in hormonal pathways. Our study highlights the existence of pleiotropic regulation of seed traits by hub developmental regulators such as PEP1, suggesting that seed and flowering traits in perennial plants might be optimized in a coordinated fashion.

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