33 research outputs found

    Finishing the euchromatic sequence of the human genome

    Get PDF
    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 Geological, Isotopic, Botanical, Invertebrate, and Lower Vertebrate Surroundings of Ardipithecus ramidus

    No full text
    International audienceSediments containing Ardipithecus ramidus were deposited 4.4 million years ago on an alluvial floodplain in Ethiopia's western Afar rift. The Lower Aramis Member hominid-bearing unit, now exposed across a >9-kilometer structural arc, is sandwiched between two volcanic tuffs that have nearly identical (40)Ar/(39)Ar ages. Geological data presented here, along with floral, invertebrate, and vertebrate paleontological and taphonomic evidence associated with the hominids, suggest that they occupied a wooded biotope over the western three-fourths of the paleotransect. Phytoliths and oxygen and carbon stable isotopes of pedogenic carbonates provide evidence of humid cool woodlands with a grassy substrate

    Evolutionary divergence and convergence in shape and size within African antelope proximal phalanges

    No full text
    Morphological convergence amongst species inhabiting similar environments but having different evolutionary histories is a concept central to evolutionary biology. Cases of divergent evolution, where there is morphological divergence between closely related species exploiting different environments, are less well studied. Here we show divergent evolution in the morphology of the proximal phalanges of several closely related African antelope species inhabiting different environments. This morphological divergence was consistently observed in both a neutral morphospace and an externally ordinated morphospace. Divergence, but not convergence, was also observed when size and shape were considered independently. Finally, convergent evolution of the morphology of the proximal phalanges was observed, but only in the externally ordinated morphospace. Size shows less correlation with phylogeny than does shape. Therefore, we suggest that divergence in size will occur more readily when a species encounters new environmental conditions than divergence in shape. These findings are compatible with observations of rapid dwarfing on islands (Foster's rule)
    corecore