Philogenetics

En este trabajo de consulta se hablará detalladamente de cada aspecto biológico de Therapsida, incluyendo sus orígenes evolutivos, estructuras corporales, diversidad, planes de alimentación, especiación y extinción tanto como la literatura lo permita. Con ayudas como árboles filogenéticos y representaciones del organismo que será objeto de estudio en el presente texto.

Molecular phylogenies describe the study of evolution relationships between living beings, protein and genetic sequences and other molecular taxons. In recent years there has been increased interest in producing large and accurate phylogenies trees using some numerical computational methods approach. One class of molecular phylogenies is the distance matrices method, with the matrix whose entries represent the distinctions between the taxons under study. To construct large and accurate trees for a large number of taxons, the computational processing increases and parallel computing can be helpful. So far we have tested some methods to solve the linear systems, being driven to important conclusions, like which is the best tested method, and having also reached some questions about communication. *

Chitin is a structural endogenous carbohydrate, which is a major component of fungal cell walls and arthropod exoskeletons. A renewable resource and the second most abundant polysaccharide in nature after cellulose, chitin is currently used for waste water clearing, cosmetics, medical, and veterinary applications. This work comprises data mining of protein sequences related to the chitin metabolic pathway of completely sequenced genomes of extant organisms pertaining to the three life domains, followed by meta-analysis using traditional sequence similarity comparison and complex network approaches. Complex networks involving proteins of the chitin metabolic pathway in extant organisms were constructed based on protein sequence similarity. Several usual network indices were estimated in order to obtain information on the topology of these networks, including those related to higher order neighborhood properties. Due to the assumed evolutionary character of the system, we also discuss issues related to modularity properties, with the concept of edge betweenness playing a particularly important role in our analysis. Complex network approach correctly identifies clusters of organisms that belong to phylogenetic groups without any a priori knowledge about the biological features of the investigated protein sequences. We envisage the prospect of using such a complex network approach as a high-throughput phylogenetic method.

The US American pathologist and microbiologist Howard Taylor Ricketts died 100 years ago. He is renowned for discovering the causative organism and the transmission route of Rocky Mountain spotted fever and of tabardillo e an epidemic louse-borne typhus occurring especially in Mexico. He also found that both diseases were caused by related infectious agents (Rickettsia rickettsii and Rickettsia prowazekii). The scientific community therefore named both a taxonomic family (Rickettsiaceae) and an order (Rickettsiales) after the scientist. Ricketts' work on immunity and serums became the basis for further advances in vaccine development.

The discovery of a living coelacanth specimen in 1938 was remarkable, as this lineage of lobe-finned fish was thought to have become extinct 70 million years ago. The modern coelacanth looks remarkably similar to many of its ancient relatives, and its evolutionary proximity to our own fish ancestors provides a glimpse of the fish that first walked on land. Here we report the genome sequence of the African coelacanth, Latimeria chalumnae. Through a phylogenomic analysis, we conclude that the lungfish, and not the coelacanth, is the closest living relative of tetrapods. Coelacanth protein-coding genes are significantly more slowly evolving than those of tetrapods, unlike other genomic features. Analyses of changes in genes and regulatory elements during the vertebrate adaptation to land highlight genes involved in immunity, nitrogen excretion and the development of fins, tail, ear, eye, brain and olfaction. Functional assays of enhancers involved in the fin-to-limb transition and in the emergence of extra-embryonic tissues show the importance of the coelacanth genome as a blueprint for understanding tetrapod evolution.

Felieton poświęcony jest teorii ewolucji Darwina. W sposób popularny opisano, na czym ta teoria polega, jak została przyjęta w momencie jej ogłoszenia (emocjonalnie) i jak najnowsze badania oparte na genetyce zmuszają do jej aktualizacji. W szczególności dyskutowana jest kwestia tzw. drzewa filogenetycznego.

En 1956 Tecia solanivora fue reportada por primera vez en Centroamérica, insecto Lepidóptero de la familia Gelechiidae, causando pérdidas económicas a los cultivos de papa (Solanum tuberosum). A pesar de que se considera como un insecto de movilidad reducida, ha invadido varios países en Centro y Sur américa así como las Islas Canarias en España. El daño se ha detectado en campos así como en tubérculos almacenados con promedios superiores al 50% de la capacidad de producción. El Impacto económico de la plaga en países del área andina es mucho mas serio que en Centro América, principalmente debido a que la papa es un importante alimento básico de las familias y su producción es intensiva, razones por las cuales T. solanivora es considerada la plaga mas perjudicial del cultivo de la papa en diferentes países. Aquí se presenta el conocimiento científico actual alrededor de T. solanivora, desde su origen y dispersión a través de los países, las implicaciones en los cultivos de papa, las estrategias desarrolladas para controlar su impacto, así como el conocimiento generado sobre la filogeografía y genética de poblaciones de T. solanivora, conocimiento esencial para complementar las estrategias de manejo integrado de ésta plaga.