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One of the most important functions of forests is their capacity to store carbon, which varies according to floristic composition, age, and tree density. To provide information that is useful for the carbon inventories, the construction of growth curves for dominant strata within the study area was set as the objective of this work. With data from the National Forest and Soil Inventory 2005-2009 were calculated the IVI by conglomerate and from a dendrogram performed with cluster analysis, using the Ward's linkage method, dominant strata were formed. A growth curve per community was constructed based on the maximum yields per hectare recorded in the forestry management plans, the percentage increases were attributed to volume per species at different ages, which was obtained by ICA through trunk analysis. Five dominant strata were formed; Pinus oocarpa (21.08 % to 54.38 %), Pinus douglasiana (41.45 % to 89.83 %), Pinus devoniana (27.53 % to 63.88 %), Pinus leiophylla (27.53 % to 89.03 %) and Quercus spp. (36.05 % to 93.26 %). The maximum yields for the stands within the study area were 329.98 m3 ha-1, 330.71 m3 ha-1, 171.35 m3 ha-1, 185.22 % and 127. 46 m3 ha-1, respectively. The Pinus oocarpa and Pinus douglasiana dominant strata are had the highest percentage increases in the region due to their historical foment. [ABSTRACT FROM AUTHOR]

Which came first, the chicken or the egg? That is not a pun, joking or irrelevant question. Two hypotheses have tried to answer it. The first, and accepted for years, proposes that the evolutionary process went from oviparity, through an Embryonic Retention (ER) phase, to viviparity. In other words, the simpler egg came first, which hatched into the more complex chicken. That is known as the terrestrial model. Indeed, fishes typically lay eggs, albeit some sharks are viviparous. Even some living (extant) mammals are oviparous, (monotremes like platypus and echidnas). But new evidence has challenged such traditional view, proposing that it was the other way round. Thus, first came the chicken, which eventually laid the egg. That is the Extended Embryo-Retention (EER) model. In the first evolutionary step of this scenario, ancient reptiles, birds and mammals gave birth to offspring. Subsequently, some of them developed oviparity. Indeed, several archaeological and phylogenetic discoveries have shown that first, during the ER period, thin layers of tissues (extraembryonic membranes) evolved for a better development of the embryo, given rise to the amniotes. It is known that living reptiles (like crocodiles and turtles) and birds typically show non-EER oviparity. But curiously, most lizards, snakes and mammals exhibit oviparity with EER or viviparity. While the debate continues, both archaeology and molecular biology will contribute to clarify this interesting topic. [ABSTRACT FROM AUTHOR]

Microsatellites were used to evaluate and compare the lineage relationships and genetic diversity of two improved cultivars of corn (Zea mays L.), seven modern native races, and eight archaeological Chimú samples (1.100-1.500 AD) of the North Peruvian coast. Electrophoresis was required to remove the PCR inhibitors from ancient DNA. Eight STR primer pairs generated amplicons from the genome of modern corn, but only five amplified ancient corn DNA. To establish the lineage relationships among samples, the coefficient of similarity of Jaccard and the technique of analysis of conglomerate with binding average were used. Thus, the pattern of genealogical and genetic relationships of the genotypes were determined. Seven out of the eight pairs of SSR primers revealed polymorphism, being 2.47 (range 2-6) the average of polymorphic alleles. The total alleles tested were 23, with 97 polymorphic bands for the modern corn, yet being monomorphic for the Chimú corn, generating an average of genetic similarity of 0.44 and 1, respectively. These results suggest the existence of inbreeding in some populations of Chimú corn of the north coast of Peru 500 to 900 years ago. Modern races exhibited higher polymorphism, due to hybridization and better assisted selection, in agreement with cytogenetic data. [ABSTRACT FROM AUTHOR]

In this work, we analyzed the richness and biogeographic relations of Papilionoidea at the Mexican Gulf Biogeographic Province. It applied PAE and Jaccard index at 24 sites and we find 793 species was associated at high evergreen tropical forest (ETF), of which 218 were Exclusives species in this vegetation type and they can used in conservation studies and 86 of these as Restricted with limited distribution in ETF. In this analysis, the studied sites formed two groups, one at north and another at south of the Sierra Chiconquiaco. These groups support the idea of the Mexican Gulf biogeographic province separated in two districts. [ABSTRACT FROM AUTHOR]

Glucose is preferentially stored as starch in plants. Thus, the remains of such polysaccharide may represent an invaluable source of archaeological evidence. The genomics, proteomics and metabolomics pathways can be also exploited to ascertain key events in phylogenetic processes. This includes the reconstruction of polyploidization events in plants and the identification of taxonomic positions. These developments are particularly relevant for the study of selection, evolution and domestication events of microorganisms, plants and animals. They include the adaptation to such food resource and the study of paleodiets and their implications for ancient and modern animals, including humans. [ABSTRACT FROM AUTHOR]

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Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)