Evolution

  • Article
    | Open Access

    Zebra finches are passerine birds, but their phylogenetic relationship with non-passerine birds remains controversial. By examining retroposon insertion loci in avian genomes, the authors reveal that parrots are the closest relatives of passerines, which may have implications for understanding the evolution of birdsong.

    • Alexander Suh
    • , Martin Paus
    •  & Jürgen Schmitz
  • Article |

    Antisocial punishment, where non-cooperators punish cooperators, is a puzzling empirical phenomenon missing from most theoretical models. Here, antisocial punishment is added to an optional public goods game, revealing that evolution favours antisocial punishment and punishment does not promote cooperation.

    • David G. Rand
    •  & Martin A. Nowak
  • Article |

    Why some species have evolved to produce sterile individuals working for the benefit of others has yet to be fully explained. Now, a mathematical model of the dynamics of insect colony foundation, growth and death shows that monogamy and haplodiploidy facilitate the evolution of this societal structure.

    • Lutz Fromhage
    •  & Hanna Kokko
  • Article |

    Studies of male genitalia show patterns of divergent evolution, whereas females have been less well studied. Using experimental evolution and quantitative genetic analysis, Simmons and Garcia-Gonzalez show that sexual selection drives the coevolution of female and male genital morphology in the dung beetleOnthophagus taurus.

    • Leigh W. Simmons
    •  & Francisco Garcia-Gonzalez
  • 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
  • Article |

    The cryptic Wood White butterflies,Leptidea sinapis and Leptidea reali, represent a model for the study of speciation. Dincă et al. use DNA and chromosome data to show that this group, in fact, consists of a triplet of species, a result that provides a new perspective on cryptic biodiversity.

    • Vlad Dincă
    • , Vladimir A. Lukhtanov
    •  & Roger Vila
  • Article
    | Open Access

    Global darkness from an asteroid impact 65.5 million years ago led to massive extinction of oceanic phytoplankton, but coastal groups survived. Ribeiroet al.revive coastal dinoflagellates after a century of dormancy, suggesting phytoplankton survived the extinction and helped restore photosynthesis in the ocean.

    • Sofia Ribeiro
    • , Terje Berge
    •  & Marianne Ellegaard
  • Article
    | Open Access

    Saccharomycesyeasts can produce ethanol from sugars in the presence of oxygen. In this study, the authors demonstrate thatDekkera bruxellensis, a distantly related yeast, can also produce and consume ethanol due to the loss of a cis-regulatory element from the promoters of genes crucial for respiration.

    • Elżbieta Rozpędowska
    • , Linda Hellborg
    •  & Jure Piškur
  • Article
    | Open Access

    Cyanide-releasing defence systems in plants and animals are important to the evolution of plant–herbivore interactions. The authors identify the enzymes responsible for biosynthesis of cyanogenic glucosides by Six-spot Burnet moth caterpillars, which have evolved independently from the known plant pathway.

    • Niels Bjerg Jensen
    • , Mika Zagrobelny
    •  & Søren Bak
  • Article
    | Open Access

    Plasmids are present in many bacteria and are often transferred between different species causing horizontal gene transfer. By comparing the sequences of 25 plasmid DNA backbones, the authors show that homologous recombination is prevalent in plasmids and that the plasmids have adapted to persist in different host bacteria.

    • Peter Norberg
    • , Maria Bergström
    •  & Malte Hermansson
  • Article
    | Open Access

    Many animals can do simple quantity discrimination, but they often perform poorly when food is used. Here, the authors show that monkeys are good at food quantity discrimination when they are not allowed to eat it, suggesting that the mental representation of the stimuli is more important than the physical quality.

    • Vanessa Schmitt
    •  & Julia Fischer
  • Article |

    Matrilocal and patrilocal populations are predicted to have greater genetic diversity in mitochondrial DNA and the Y-chromosome, respectively. Here, no difference in the diversity of the Y-chromosome was found in two such groups, suggesting that local diversity was caused by male gene flow in expanding populations.

    • Ellen Dröfn Gunnarsdóttir
    • , Madhusudan R. Nandineni
    •  & Mark Stoneking
  • Article |

    Storm water runoff and wastewater effluent are discharged into oceans, but the full ecological effects of these discharges are unknown. Here, the authors examine the population structure of a marine organism, the bat star, and show that these discharges alter the genetic structure and larval dispersal of this species.

    • Jonathan B. Puritz
    •  & Robert J. Toonen
  • Article
    | Open Access

    Organisms are expected to adapt to climate change because of selection pressures. Here, the authors demonstrate that brown morphs of Finnish owls are selected against in winters with plentiful snow, and concordantly, increasing winter temperatures and lower snow fall results in the selection of the brown morph.

    • Patrik Karell
    • , Kari Ahola
    •  & Jon E. Brommer
  • Article |

    Trees of the genusEucalyptusdominate the flora in Australia and can undergo resprouting after fire. Here, fossils and DNA of eucalypts reveal that the resprouting feature of the trees can be linked to the evolution of fire biomes, and that this likely began 60 million years ago.

    • Michael D. Crisp
    • , Geoffrey E. Burrows
    •  & David M. J. S. Bowman
  • Article
    | Open Access

    HrpR and HrpS enhancer-binding proteins ofPseudomonas syringae activate σ54-dependent transcription of the HrpL promoter and are required for type-three secretion pathogenicity. Here, the authors demonstrate that, despite being co-regulated, HrpR and HrpS each have distinct functions for activating σ54.

    • Milija Jovanovic
    • , Ellen H. James
    •  & Jörg Schumacher
  • Article
    | Open Access

    Microorganisms are abundant in many environments and understanding their dispersal between ecosystems is important for ecology and conservation. These authors demonstrate that cyanobacterial populations are specific to hot or cold deserts and that gene flow between different populations does not occur.

    • Justin Bahl
    • , Maggie C. Y. Lau
    •  & Stephen B. Pointing
  • Article |

    Some organisms produce unequal numbers of male and female progeny, but the mechanics of skewed of sex ratios are largely unknown. Here, the authors describe alterations in X-chromosome segregation and cytoplasmic partitioning during spermatogenesis that together explain the distorted sex ratio in a nematode species.

    • Diane C. Shakes
    • , Bryan J. Neva
    •  & Andre Pires-daSilva
  • Article |

    Insertion sequences are transposable elements that are found in the genomes of many bacteria. Here, the authors identify an enhancer element that results in a high frequency of excision of insertion elements, and suggest that the excision enhancer element coevolved with the insertion sequences.

    • Masahiro Kusumoto
    • , Tadasuke Ooka
    •  & Tetsuya Hayashi
  • Article
    | Open Access

    Up to 20% of bacterial genomes are made up of cryptic prophages, but their function is relatively unknown. In this study, the authors demonstrate that prophages influence the response of the host cell to stress and provide a competitive growth advantage in the presence of antibiotics.

    • Xiaoxue Wang
    • , Younghoon Kim
    •  & Thomas K. Wood
  • Article
    | Open Access

    A single gene results in either dextral or sinistral snail shell coiling and snails with different coils cannot copulate. Here, the authors provide evidence of how such an allele can become fixed in a population by showing that snails with a counterclockwise sinistral coil are protected from predators.

    • Masaki Hoso
    • , Yuichi Kameda
    •  & Michio Hori
  • Article
    | Open Access

    Sixty years ago it was suggested that the sickle cell disease mutation survives because the heterozygous genotype confers resistance to malaria, resulting in correlation of the two geographical distributions. The authors use a new global assembly of sickle allele frequencies to support this hypothesis at the global scale.

    • Frédéric B. Piel
    • , Anand P. Patil
    •  & Simon I. Hay
  • Article |

    Symbiotic fungi are thought to have assisted plants in their colonization of the land. In this study, it is shown that mycorrhizal fungi symbiosis with liverwort, a member of an ancient clade of land plants, promotes photosynthetic carbon uptake and growth, supporting the role of fungi in 'the greening of the Earth'.

    • Claire P. Humphreys
    • , Peter J. Franks
    •  & David J. Beerling
  • Article |

    A crucial transition in the origin of life was the emergence of self-replicating RNA and its compartmentalization within protocellular structures. Here it is shown that the physicochemical properties of ice, a simple medium widespread on a temperate early earth, could have mediated this transition.

    • James Attwater
    • , Aniela Wochner
    •  & Philipp Holliger
  • Article
    | Open Access

    Many animals have complex body patterns, which are fixed in some species and flexible in others. Here, using reaction-diffusion mathematical models, together with salmonid fish crosses, intermediate patterns are shown to occur in hybrid animals produced by mating species with different flexible patterns.

    • Seita Miyazawa
    • , Michitoshi Okamoto
    •  & Shigeru Kondo
  • Article |

    The emergence of bipedalism in humans is considered to be an evolutionary challenge. In this study, however, the authors show that humans, dogs and chickens create a virtual pivot point above their centre of mass during walking, thereby mimicking an external support.

    • H.-M. Maus
    • , S.W. Lipfert
    •  & A. Seyfarth
  • Article
    | Open Access

    Spotted hyaenas live in clans with a hierarchy of females with different social ranks. In this paper, the sons of high-ranking female hyaenas are shown to have greater fitness than sons born of mothers of medium and low rank. This study highlights the importance of maternal effects in evolution.

    • Oliver P. Höner
    • , Bettina Wachter
    •  & Marion L. East
  • Article
    | Open Access

    Female water striders have evolved a strategy to control the frequency of copulation. In this article, male water striders are shown to attract predators during copulation to coerce the female into yielding more quickly. These findings demonstrate how adaptive behaviour may be influenced by predation.

    • Chang S. Han
    •  & Piotr G. Jablonski
  • Article
    | Open Access

    It was previously thought that the nerves in the pectoral fin of fish came solely from the spinal cord. Here, motoneurons in ray-finned fish are shown to also originate from the hindbrain, demonstrating that innervation was from both the hindbrain and the spinal cord in ancesteral vertebrates.

    • Leung-Hang Ma
    • , Edwin Gilland
    •  & Robert Baker
  • Article
    | Open Access

    The embryonic development of forelimbs and hindlimbs is regulated by transcription factors, including Pitx1, Tbx4 and Tbx5. In this study, the contributions of Tbx4 and Tbx5 to limb identity are further delineated, resulting in the demonstration of a role for Tbx4 in hindlimb skeletal and muscle patterning.

    • Jean-François Ouimette
    • , Marisol Lavertu Jolin
    •  & Jacques Drouin
  • Article |

    Adoption is an altruistic behaviour that incurs parental costs. Gorrellet al. examined more than 2,000 squirrel litters and showed that red squirrels adopt only their kin, resulting in an increase in their inclusive fitness. These data provide support for Hamilton's rule of altruism.

    • Jamieson C. Gorrell
    • , Andrew G. McAdam
    •  & Stan Boutin
  • Article
    | Open Access

    Many animals communicate through gestures, some caterpillars use scraping and drumming signals to ward off unwanted neighbours. Here, Scottet al. demonstrate that "leg-like" structures used by some caterpillar species to communicate evolved from legs that their ancestors used to walk.

    • Jaclyn L. Scott
    • , Akito Y. Kawahara
    •  & Jayne E. Yack