Prodromus of Vertebrate Paleontology and Geochronology of Bermuda

Les fluctuacions pleistocèniques del nivell de la mar han estat el primer determinant de la deposició geològica i l'evolució biòtica a Bermuda. Lilla està composta d'arenes carbonatades dipositades sobre el cim erosionat d'un volcà submarí durant el decurs de nivells de la mar elevats dels períodes interglacials. A partir de les arenisques interglaciars s'han obtingut unes poques restes de vertebrats, principalment d'edat pleístocènica mitja. Els intervals glacials estan marcats per sols vermells, derivats principalment de la pols atmosfèrica. Els vertebrats fòssils d'edat glacial no es troben preservats a la superfície i només es coneixen de coves i rebliments de fissures. A Bermuda es coneixen faunes fòssils dels darrers dos episodis glacials, però no dels anteriors. Es coneixen extincions certes o probables de vertebrats correlacionades amb, com a minim, quatre pujades interglacials del nivell de la mar (estadis isotòpics marins, MIS, 11,9,5 i 1). Es revisa la història de la paleontologia de vertebrats a Bermuda i s'allisten i es descriuen breument les localitats de vertebrats fòssils.Pleistocene sea-level fluctuations were the primary determinant of geological deposition and biotic evolution on Bermuda. The island is composed of carbonate sand deposited on the eroded summit of a submarine volcano during elevated sea-levels of interglacial periods. A few vertebrate remains have been recovered directly from interglacial sandstones, mainly of mid-Pleistocene age. Glacial intervals are marked by red soils derived mainly from atmospheric dust. Vertebrate fossils of glacial age are not preserved at the surface and are known only from caves and fissure fills. Fossil faunas are known on Bermuda from the last two glacial episodes but none of the earlier ones. Certain or probable extinctions of vertebrates are correlated with at least four interglacial rises in sea-level--Marine Isotope Stages (MIS) 11,9,5, and 1. The history ofvertebrate paleontology on Bermuda is reviewed and fossil vertebrate localities are listed and briefly described

Community structure of Pleistocene coral reefs of Curaçao, Netherlands Antilles

The Quaternary fossil record of living coral reefs is fundamental for understanding modern ecological patterns. Living reefs generally accumulate in place, so fossil reefs record a history of their former biological inhabitants and physical environments. Reef corals record their ecological history especially well because they form large, resistant skeletons, which can be identified to species. Thus, presence-absence and relative abundance data can be obtained with a high degree of confidence. Moreover, potential effects of humans on reef ecology were absent or insignificant on most reefs until the last few hundred years, so that it is possible to analyze "natural" distribution patterns before intense human disturbance began. We characterized Pleistocene reef coral assemblages from Curacao, Netherlands Antilles, Caribbean Sea, focusing on predictability in species abundance patterns from different reef environments over broad spatial scales. Our data set is composed of >2 km of surveyed Quaternary reef. Taxonomic composition showed consistent differences between environments and along secondary environmental gradients within environments. Within environments, taxonomic composition of communities was markedly similar indicating nonrandom species associations and communities composed of species occurring in characteristic abundances. This community similarity was maintained with little change over a 40-km distance. The nonrandom patterns in species abundances were similar to those found in the Caribbean before the effects of extensive anthropogenic degradation of reefs in the late 1970s and early 1980s. The high degree of order observed in species abundance patterns of fossil reef coral communities on a scale of tens of kilometers contrasts markedly with patterns observed in previous small-scale studies of modern reefs. Dominance of Acropora palmata in the reef crest zone and patterns of overlap and nonoverlap of species in the Montastraea ''annularis'' sibling species complex highlight the tendency for distribution and abundance patterns of Pleistocene corals to reflect environmental preferences at multiple spatial scales. Wave energy is probably the most important physical environmental variable structuring these coral communities. The strong similarity between ancient and pre-1980s Caribbean reefs and the nonrandom distribution of coral species in space and time indicate that recent variability noted at much smaller time scales may be due to either unprecedented anthropogenic influences on reefs or fundamentally different patterns at varying spatio-temporal scales

Transcriptional recapitulation and subversion of embryonic colon development by mouse colon tumor models and human colon cancer

Colon tumors from four independent mouse models and 100 human colorectal cancers all exhibited striking recapitulation of embryonic colon gene expression from embryonic days 13.5-18.5

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

Prodromus of vertebrate paleontology and geochronology of Bermuda

Summary Pleistocene sea-level fluctuations were the primary determinant of geological deposition and biotic evolution on Bermuda. The island is composed of carbonate sand deposited on the eroded summit of a submarine volcano during ele- vated sea-levels of interglacial periods. A few vertebrate remains have been recovered directly from interglacial sandstones, mainly of mid-Pleistocene age. Glacial intervals are marked by red soils derived mainly from atmospheric dust. Vertebrate fossils of glacial age are not preserved at the surface and are known only from caves and fissure fills. Fossil faunas are known on Bermuda from the last two glacial episodes but none of the earlier ones. Certain or probable extinctions of vertebrates are correlated with at least four interglacial rises in sea-level—-Marine Isotope Stages (MIS) 11, 9, 5, and 1. The history of verte- brate paleontology on Bermuda is reviewed and fossil vertebrate localities are listed and briefly described