Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

THE REVEREND C.G.NICOLAY-WESTERN AUSTRALIA\u27S FIRST MUSEUM CURATOR

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Environmental Pressures Influencing Living Stromatolites In Hamelin Pool, Shark Bay, Western Australia

Environmental parameters in Hamelin Pool, Shark Bay were investigated to characterize extrinsic factors that may be affecting stromatolite morphogenesis. Hamelin Pool, which evolved into a restricted environment during the last few millennia, sustains the world's most extensive and diverse assemblage of modern marine stromatolites. These stromatolites occur in a shallow nearshore facies belt covering over 100 km of coast. Temperature, salinity, water level, and current data collected between 2012 and 2014 have revealed previously undocumented regional and seasonal trends. Regional trends include increasing salinity, greater temperature range, and decreasing energy moving southward from Faure Sill and to the Nilemah Embayment. Seasonal trends reveal paradoxically increased salinities in wet winter months and decreased salinity in dry summer months. When paired with annual tidal cycles, these trends suggest the influx of low salinity groundwater along the Hamelin Pool shelf. Speculation on how the documented environmental parameters may affect stromatolite growth suggests potential impact on morphology, internal fabric, and stromatolite-building microbial communities. These insights into environmental pressures within a living stromatolite system provide a framework for understanding extrinsic factors affecting microbial communities and stromatolite development throughout Earth history

Stromatolite provinces of Hamelin Pool: physiographic controls on stromatolites and associated lithofacies

Recent studies recognized distinct stromatolite provinces in Hamelin Pool, Western Australia, each with morphologically distinct stromatolite structures paired with characteristic shelf physiography. In the present paper, we couple detailed lithofacies mapping with Hamelin Pool bathymetry and consider physiography as a control of sedimentation processes, including stromatolite development. Bathymetric transects, derived from a high-resolution bathymetry map with depths from 0 to 11 meters, allow calculation of slope gradients in the provinces. As in other settings, bathymetry is linked to energy regimes, which in turn appear to be coupled with variations in stromatolite morphologies and associated lithofacies as follows: (1) low-gradient ramps with low-energy settings are associated with sheet mats and elongate-clustered stromatolites that exhibit regular spatial patterns, possibly indicative of self-organization; (2) low gradients coupled with high-energy settings resulting from strong winds result in seif stromatolites with pronounced directional bands; (3) medium to steep gradients coupled with medium to high energy are associated with individual and merged stromatolites, often with thin basal necks; (4) headlands and promontories where the topography deflects currents are associated with elongate-nested stromatolites; and (5) medium- to high-energy slopes typically found at promontory edges and shelf margins are dominated by blocky pavement. Observations linking stromatolite morphology to physiography in a modern microbial system provide insight into the long-lived debate about biology versus environment in controlling stromatolite morphology. When physiography leads to a high-energy regime, environmental controls are the main factor determining stromatolite morphology. In contrast, when physiography promotes a low-energy environment, the response of biological communities becomes the main driver of macroscale stromatolite morphology