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Wheat (Triticum spp.) is one of the founder crops that likely drove the Neolithic transition to sedentary agrarian societies in the Fertile Crescent more than 10,000 years ago. Identifying genetic modifications underlying wheat’s domestication requires knowledge about the genome of its allo-tetraploid progenitor, wild emmer (T. turgidum ssp. dicoccoides). We report a 10.1-gigabase assembly of the 14 chromosomes of wild tetraploid wheat, as well as analyses of gene content, genome architecture, and genetic diversity. With this fully assembled polyploid wheat genome, we identified the causal mutations in Brittle Rachis 1 (TtBtr1) genes controlling shattering, a key domestication trait. A study of genomic diversity among wild and domesticated accessions revealed genomic regions bearing the signature of selection under domestication. This reference assembly will serve as a resource for accelerating the genome-assisted improvement of modern wheat varieties.

An analysis of 16 health-related quantitative traits in approximately 350,000 individuals reveals statistically significant associations between genome-wide homozygosity and four complex traits (height, lung function, cognitive ability and educational attainment); in each case increased homozygosity associates with a decreased trait value, but no evidence was seen of an influence on blood pressure, cholesterol, or ten other cardio-metabolic traits. Parental relatedness link to height and intelligence This consortium meta-analysis of 102 cohorts and more than 350,000 individuals investigates the effects of homozygosity on traits of public health importance by observing contiguous homozygous segments (runs of homozygosity, ROH), which are inferred to be homozygous along their complete length. Focusing on 16 health-related quantitative traits, the authors find statistically significant associations between summed runs of homozygosity and four complex traits: height, forced expiratory lung volume in a second, general cognitive ability and educational attainment. In each case increased homozygosity associates with decreased trait value. No evidence was seen of an influence of genome-wide homozygosity on blood pressure and low density lipoprotein cholesterol, or ten other cardio-metabolic traits. Homozygosity has long been associated with rare, often devastating, Mendelian disorders 1 , and Darwin was one of the first to recognize that inbreeding reduces evolutionary fitness 2 . However, the effect of the more distant parental relatedness that is common in modern human populations is less well understood. Genomic data now allow us to investigate the effects of homozygosity on traits of public health importance by observing contiguous homozygous segments (runs of homozygosity), which are inferred to be homozygous along their complete length. Given the low levels of genome-wide homozygosity prevalent in most human populations, information is required on very large numbers of people to provide sufficient power 3 , 4 . Here we use runs of homozygosity to study 16 health-related quantitative traits in 354,224 individuals from 102 cohorts, and find statistically significant associations between summed runs of homozygosity and four complex traits: height, forced expiratory lung volume in one second, general cognitive ability and educational attainment ( P < 1 × 10 −300 , 2.1 × 10 −6 , 2.5 × 10 −10 and 1.8 × 10 −10 , respectively). In each case, increased homozygosity was associated with decreased trait value, equivalent to the offspring of first cousins being 1.2 cm shorter and having 10 months’ less education. Similar effect sizes were found across four continental groups and populations with different degrees of genome-wide homozygosity, providing evidence that homozygosity, rather than confounding, directly contributes to phenotypic variance. Contrary to earlier reports in substantially smaller samples 5 , 6 , no evidence was seen of an influence of genome-wide homozygosity on blood pressure and low density lipoprotein cholesterol, or ten other cardio-metabolic traits. Since directional dominance is predicted for traits under directional evolutionary selection 7 , this study provides evidence that increased stature and cognitive function have been positively selected in human evolution, whereas many important risk factors for late-onset complex diseases may not have been.

Jeffries, D.L., Lavanchy, G., Sermier, R., Sredl, M.J., Miura, I., Borzée, A., Barrow, L.N., Canestrelli, D., Crochet, P.-A., Dufresnes, C., Fu, J., Ma, W.-J., Garcia, C.M., Ghali, K., Nicieza, A.G., O’Donnell, R.P., Rodrigues, N., Romano, A., Martínez-Solano, Í., Stepanyan, I., Zumbach, S., Brelsford, A., Perrin, N.

Photosynthetic eukaryotes thrive anywhere there is sunlight and water. But while such organisms are exceptionally diverse in form and function, only one phototrophic lineage succeeded in rising above its substrate: the land plants (embryophytes). Molecular phylogenetic data show that land plants evolved from streptophyte algae most closely related to extant Zygnematophyceae, and one of the principal aims of plant evolutionary biology is to uncover the key features of such algae that enabled this important transition. At the present time, however, mosaic and reductive evolution blur our picture of the closest algal ancestors of plants. Here we discuss recent progress and problems in inferring the biology of the algal progenitor of the terrestrial photosynthetic macrobiome.

Ferns are the closest sister group to all seed plants, yet little is known about their genomes other than that they are generally colossal. Here, we report on the genomes of Azolla filiculoides and Salvinia cucullata (Salviniales) and present evidence for episodic whole-genome duplication in ferns—one at the base of ‘core leptosporangiates’ and one specific to Azolla. One fernspecific gene that we identified, recently shown to confer high insect resistance, seems to have been derived from bacteria through horizontal gene transfer. Azolla coexists in a unique symbiosis with N2-fixing cyanobacteria, and we demonstrate a clear pattern of cospeciation between the two partners. Furthermore, the Azolla genome lacks genes that are common to arbuscular mycorrhizal and root nodule symbioses, and we identify several putative transporter genes specific to Azolla–cyanobacterial symbiosis. These genomic resources will help in exploring the biotechnological potential of Azolla and address fundamental questions in the evolution of plant life.

We studied the evolutionary history of the Parmeliaceae (Lecanoromycetes, Ascomycota),one of the largest families of lichen-forming fungi with complex and variable morphologies,also including several lichenicolous fungi. We assembled a six-locus data set including nuclear, mitochondrial and low-copy protein-coding genes from 293 operational taxonomic units (OTUs). The lichenicolous lifestyle originated independently three times in lichenized ancestorswithin Parmeliaceae, and a new generic name is introduced for one of these fungi. In all cases,the independent origins occurredc. 24 million yr ago. Further, we show that the Paleocene,Eocene and Oligocene were key periods when diversification of major lineages within Parmeli-aceae occurred, with subsequent radiations occurring primarily during the Oligocene andMiocene. Our phylogenetic hypothesis supports the independent origin of lichenicolous fungi associ-ated with climatic shifts at the Oligocene–Miocene boundary. Moreover, diversification burstsat different times may be crucial factors driving the diversification of Parmeliaceae. Addition-ally, our study provides novel insight into evolutionary relationships in this large and diversefamily of lichen-forming ascomycetes. ancestral characterreconstruction, Ascomycota, lichenicolousfungi, mutualism, Parmeliaceae, phylogeny, Raesaenenia

The authors analyse the tempo and geography of diversification for all 10,000 species of birds: diversification has sped up over time, bursts are spread out across the tree and across the world, and high rates are not concentrated in the tropics. How birds got where they are today There are almost 10,000 bird species alive today. Here Walter Jetz et al . present an analysis of the evolutionary relationships, in time and space, between all of these bird populations. The resulting evolutionary tree reveals that the rate of diversification has increased in the past 50 million years, suggesting that the 'bird niche' is not yet full. Recent evolutionary success is not evenly distributed, with songbirds, waterfowl, gulls and woodpeckers among the winners. Despite greater diversity near the Equator, diversification rates are particularly low in Africa, South-East Asia and Australia. Current global patterns of biodiversity result from processes that operate over both space and time and thus require an integrated macroecological and macroevolutionary perspective 1 , 2 , 3 , 4 . Molecular time trees have advanced our understanding of the tempo and mode of diversification 5 , 6 , 7 and have identified remarkable adaptive radiations across the tree of life 8 , 9 , 10 . However, incomplete joint phylogenetic and geographic sampling has limited broad-scale inference. Thus, the relative prevalence of rapid radiations and the importance of their geographic settings in shaping global biodiversity patterns remain unclear. Here we present, analyse and map the first complete dated phylogeny of all 9,993 extant species of birds, a widely studied group showing many unique adaptations. We find that birds have undergone a strong increase in diversification rate from about 50 million years ago to the near present. This acceleration is due to a number of significant rate increases, both within songbirds and within other young and mostly temperate radiations including the waterfowl, gulls and woodpeckers. Importantly, species characterized with very high past diversification rates are interspersed throughout the avian tree and across geographic space. Geographically, the major differences in diversification rates are hemispheric rather than latitudinal, with bird assemblages in Asia, North America and southern South America containing a disproportionate number of species from recent rapid radiations. The contribution of rapidly radiating lineages to both temporal diversification dynamics and spatial distributions of species diversity illustrates the benefits of an inclusive geographical and taxonomical perspective. Overall, whereas constituent clades may exhibit slowdowns 10 , 11 , the adaptive zone into which modern birds have diversified since the Cretaceous may still offer opportunities for diversification.

The mutualistic symbiosis involving Glomeromycota, a distinctive phylum of early diverging Fungi, is widely hypothesized to have promoted the evolution of land plants during the middle Paleozoic. These arbuscular mycorrhizal fungi (AMF) perform vital functions in the phosphorus cycle that are fundamental to sustainable crop plant productivity. The unusual biological features of AMF have long fascinated evolutionary biologists. The coenocytic hyphae host a community of hundreds of nuclei and reproduce clonally through large multinucleated spores. It has been suggested that the AMF maintain a stable assemblage of several different genomes during the life cycle, but this genomic organization has been questioned. Here we introduce the 153-Mb haploid genome of Rhizophagus irregularis and its repertoire of 28,232 genes. The observed low level of genome polymorphism (0.43 SNP per kb) is not consistent with the occurrence of multiple, highly diverged genomes. The expansion of mating-related genes suggests the existence of cryptic sex-related processes. A comparison of gene categories confirms that R. irregularis is close to the Mucoromycotina. The AMF obligate biotrophy is not explained by genome erosion or any related loss of metabolic complexity in central metabolism, but is marked by a lack of genes encoding plant cell wall-degrading enzymes and of genes involved in toxin and thiamine synthesis. A battery of mycorrhiza-induced secreted proteins is expressed in symbiotic tissues. The present comprehensive repertoire of R. irregularis genes provides a basis for future research on symbiosis-related mechanisms in Glomeromycota.

How do we understand and explain the apparent dichotomy between plasticity and robustness in the context of development? Can we identify these complex processes without resorting to 'either/or' solutions? Written by two leaders in the field, this is the first book to fully unravel the complexity of the subject, explaining that the epigenetic processes generating plasticity and robustness are in fact deeply intertwined. It identifies the different mechanisms that generate robustness and the various forms of plasticity, before considering the functional significance of the integrated mechanisms and how the component processes might have evolved. Finally, it highlights the ways in which epigenetic mechanisms could be instrumental in driving evolutionary change. Essential reading for biologists and psychologists interested in epigenetics and evolution, this book is also a valuable resource for biological anthropologists, sociobiologists, child psychologists and paediatricians.

Modern attempts to produce biogeographic maps focus on the distribution of species, and the maps are typically drawn without phylogenetic considerations. Here, we generate a global map of zoogeographic regions by combining data on the distributions and phylogenetic relationships of 21,037 species of amphibians, birds, and mammals. We identify 20 distinct zoogeographic regions, which are grouped into 11 larger realms. We document the lack of support for several regions previously defined based on distributional data and show that spatial turnover in the phylogenetic composition of vertebrate assemblages is higher in the Southern than in the Northern Hemisphere. We further show that the integration of phylogenetic information provides valuable insight on historical relationships among regions, permitting the identification of evolutionarily unique regions of the world.