Evaluación de análisis de endemicidad y PAE para identificar trazos generalizados, a partir de las serpientes del estado de Hidalgo, México / Evaluation of PAE and endemicity analysis for identifying generalized tracks using snakes in Hidalgo, Mexico

Resumen:Uno de los conceptos centrales en la Panbiogeografía es el trazo generalizado, el cual representa una biota ancestral que se ha fragmentado por eventos geológicos y puede recuperarse a través de distintos métodos, que incluyen el análisis de simplicidad de endemismos (PAE) y el análisis de endemicidad (AE). El PAE es un método frecuentemente utilizado para la identificación de trazos generalizados, mientras que el AE fue diseñado para encontrar áreas de endemismo, pero recientemente se ha usado también para identificar trazos generalizados. En este trabajo se evaluaron ambos métodos para la identificación de los trazos generalizados a partir de los datos de 84 serpientes distribuidas en el estado de Hidalgo, México. Con el PAE se obtuvo un trazo generalizado formado por tres trazos individuales (Agkistrodon taylori, Crotalus totonacus y Pliocercus elapoides), que corresponden a sinapomorfías que apoyan al clado principal. La prueba de robustez estadística mostró un soporte del 89 %, mientras que con el AE se identificaron dos áreas de endemismo con valores del índice de endemicidad de 2.71-2.96 y 2.84- 3.09 respectivamente, las cuales fueron transformadas a trazos generalizados; el primero formado por tres trazos individuales (Micrurus bernadi, Rhadinaea marcellae y R. quinquelineata) y el segundo formado por dos trazos individuales (Geophis mutitorques y Thamnophis sumichrasti). Estos trazos generalizados pueden considerarse un solo patrón de distribución, dada la cercanía geográfica y su topología. Al compararse los métodos se observó que ambos son útiles para la identificación de trazos generalizados, y aunque son independientes, se sugiere su uso de manera complementaria. Sin embargo, para una correcta aplicación e interpretación de los resultados, es necesario considerar las bases teóricas de cada método, así como la correcta elección del tamaño de las unidades de estudio. En el caso particular del AE si se utilizan tamaños de celda pequeños éstos pueden resultar ideales para la búsqueda de patrones biogeográficos a través de límites geopolíticos y esta información puede favorecer la realización de pro- puestas de conservación a nivel estatal que consideren a las especies con distribuciones restringidas, pues la pérdida de éstas representaría la extinción de linajes únicos.

Abstract:One of the most important concepts in Panbiogeography is the generalized track, which represents an ancestral biota fragmented by geological events that can be recovered through several methods, including Parsimony analysis of endemicity (PAE) and endemicity analysis (EA). PAE has been frequently used to identify generalized tracks, while EA is primarily designed to find areas of endemicity, but has been recently proposed for identifying generalized tracks as well. In this study we evaluated these methods to find generalized tracks using the distribution of the 84 snake species of Hidalgo. PAE found one generalized track from three individual tracks (Agkistrodon taylori, Crotalus totonacus and Pliocercus elapoides), supported by 89 % of Bootstrap, and EA identified two generalized tracks, with endemicity index values of 2.71-2.96 and 2.84-3.09, respectively. Those areas were transformed to generalized tracks. The first generalized track was retrieved from three individual tracks (Micrurus bernadi, Rhadinaea marcellae and R. quinquelineata), and the second was recovered from two individual tracks (Geophis mutitorques and Thamnophis sumichrasti). These generalized tracks can be considered a unique distribution pattern, because they resembled each other and agreed in shape. When comparing both methods, we noted that both are useful for identifying generalized tracks, and although they can be used independently, we suggest their complementary use. Nevertheless, to obtain accurate results, it is useful to consider theoretical bases of both methods, along with an appropriate choice of the size of the area. Results using small-grid size in EA are ideal for searching biogeographical patterns within geopolitical limits. Furthermore, they can be used for conservation proposals at state level where endemic species become irreplaceable, and where losing them would imply the extinction of unique lineages. Rev. Biol. Trop. 64 (4): 1611-1624. Epub 2016 December 01.

Regionalización biogeográfica de la mastofauna de los bosques tropicales perennifolios de Mesoamérica / Biogeographic regionalization of the mammals of tropical evergreen forests in Mesoamerica

Mesoamerica is a biologically complex zone that expands from Southern Mexico to extreme Northern Colombia. The biogeographical patterns and relationships of the mammalian fauna associated to the Mesoamerican Tropical Evergreen Forest (MTEF) are poorly understood, in spite of the wide distribution of this kind of habitat in the region. We compiled a complete georeferenced database of mammalian species distributed in the MTEF of specimens from museum collections and scientific literature. This database was used to create potential distribution maps through the use of environmental niche models (ENMs) by using the Genetic Algorithm for Rule-Set Production (GARP) using 22 climatic and topographic layers. Each map was used as a representation of the geographic distribution of the species and all available maps were summed to obtain general patterns of species richness in the region. Also, the maps were used to construct a presence-absence matrix in a grid of squares of 0.5 degrees of side, that was analyzed in a Parsimony Analysis of Endemicity (PAE), which resulted in a hypothesis of the biogeographic scheme in the region. We compiled a total of 41 527 records of 233 species of mammals associated to the MTEF. The maximum concentration of species richness (104-138 species) is located in the areas around the isthmus of Tehuantepec, Northeastern Chiapas-Western Guatemala, Western Honduras, Central Nicaragua to Northwestern Costa Rica and Western Panama. The proposed regionalization indicates that mammalian faunas associated to these forests are composed of two main groups that are divided by the isthmus of Tehuantepec in Oaxaca in: a) a Northern group that includes Sierra Madre of Chiapas-Guatemala and Yucatan Peninsula; and b) an austral group, that contains the Pacific slope of Chiapas towards the South including Central America. Some individual phylogenetic studies of mammal species in the region support the relationships between the areas of endemism proposed, which suggest a common biogeographical history. in spite that Mesoamerica is considered one of the most important hotspots for biological conservation, the poor knowledge of the biogeographic patterns, the scarcity of protected areas, and the high rate of habitat transformation due to human activities, make prioritary the development of conservation strategies that include patterns of species richness, endemism, and mammalian associations.

Este trabajo presenta una propuesta de regionalización biogeográfica de los bosques tropicales perennifolios de Mesoamérica, resultado de un análisis de parsimonia de endemismos (PAE), utilizando modelos de nicho ecológico (GARP) con mamíferos terrestres, usando 41 527 registros para las 233 especies de mamíferos reconocidas. La regionalización propuesta muestra que los bosques tropicales perennifolios de Mesoamérica se dividen por el istmo de Tehuantepec en Oaxaca en: a) un grupo septentrional que comprende la Sierra Madre de Chiapas-Guatemala y la Península de Yucatán, y b) un grupo austral, que contiene la vertiente pacífica hacia el sur incluyendo Centroamérica. Además se encontró congruencia con trabajos filogenéticos, lo que sugiere una historia biogeográfica común.

Análisis biblioéétrico de la producción sistemática en américa latina / Bibliometric Analysis of Systematics Production in Latin America

Presento la investigación sobre las bases de datos bibliográficas Biosis, CAB, Periódica, SCI, Scopus y Zoological Record. Se estudian características para identificar cuáles y cuántas es necesario utilizar para tener la información más representativa. De 1.363 revistas analizadas, el 36,5% se encuentra en más de una base de datos y el 63,46% se registra solo en una. Zoological Record contiene 63.421 documentos, Biosis 19.079, CAB 14.363, Periódica 11.185, SCI 3.257 y Scopus 916. CAB y ZR son las más antiguas, el promedio de artículos publicados por año para Biosis fue de 6.417, ZR 433, Periódica 361, CAB 145, SCI 91 y Scopus 30. El análisis de redes muestra mayor relación entre Biosis y SCI, que comparten 16% de títulos, CAB y Biosis comparten 15%, Biosis y ZR 14%, y CAB y ZR 11%. Un análisis de parsimonia muestra que Biosis y SCI comparten más revistas y Periódica tiene más revistas exclusivas (285). Periódica publicó el 24,6% de artículos con descripciones de nuevos taxones y un promedio de 90 al año, CAB 54,6% con promedio de 82 y ZR 72,9% con 322. Ninguna de las bases de datos cumple con las características suficientes empleadas como fuente de información única, es conveniente utilizar distintas combinaciones de acuerdo con las necesidades informativas. Biosis tiene la información más exhaustiva sobre cualquier taxón actual, Zoological Record y CAB tienen una cobertura temporal amplia e incluyen principalmente animales o plantas, respectivamente. SCI tiene el mayor número de documentos en revistas de corriente principal, con referencias, citas e indicadores bibliométricos. Periódica cuenta con mayor cantidad de documentos y cobertura temporal más amplia sobre lo publicado en América Latina. El cladograma obtenido por el análisis de parsimonia resultó ser una herramienta de visualización ideal para representar las características principales de las bases de datos.

I compare six bibliographic databases with information on Latin American systematics: Biosis, CAB, Periódica, SCI, Scopus and Zoological Record. The databases are characterized and compared considering their content, temporal, typological, geographical, thematical coverage, kind of access and new taxon description, to identify which and how many should be used to be more representative. Of the 1363 journals analyzed, 36.5% are found in more than one database and 63.46% are recorded in a single one. Zoologial Record contains 63421 documents, Biosis 19079, CAB 14363, Periódica 11185, SCI 3257 and Scopus 916. CAB and ZR are the oldest databases, the average number of articles published per year was 6417 for Biosis, 433 for ZR, 361 for Periódica, 145 for CAB, 91 for SCI and 30 for Scopus. According to the network analysis, there are stronger relations between SCI and Biosis, which share at least 16% of titles, CAB and Biosis share 15%, Biosis and ZR 14%, and CAB and ZR 11%. Based on the cladogram obtained from a parsimony analysis on the shared journals, the strongest relation is between Biosis and SCI; Periódica has the largest number of exclusive journals with 285. ZR has 72.9% of published articles with descriptions of new taxa and an average of 322 a year, CAB 54.6% with 82, and Periódica 24.6% with 90. None of databases meets the characteristics to be used as a single source of information, therefore it would be appropriate to use different combinations according to the aim of the analysis. Biosis has the most comprehensive information on any current taxon, Zoological Record and CAB have a broader temporal coverage and include mainly animals or plants, respectively. SCI has the largest number of documents in mainstream journals, with references, citations and bibliometric indicators. Periódica has the largest number of documents and temporal coverage published in the area. The cladogram proved to be an optimal visualization tool to represent the main features of each data base.

Caracterización molecular de poblaciones venezolanas de Sigmodon hirsutus (Rodentia: Cricetidae)

Molecular characterization of Sigmodon hirsutus (Rodentia: Cricetidae) populations in Venezuela. Recent phylogenetic studies based on cytochrome b gene sequence, have determined that the species historically known as Sigmodon hispidus (Rodentia) from South America comprises a species S. hirsutus of paraphyletic origin. The aim of this study was to test the hypothesis that populations from Venezuela, represent the sensu strict form, ancestral haplotypes, and monophyletic subspecies. For this, 12 individual sequences from three localities of different biogeographic regions in Venezuela were evaluated and sequenced based on cyto b. Additionally, the sequences were used to develop a cladistic analysis and genetic distance calculations, and to compare this information with two individual sequences of Sigmodon specimens available in Genbank. Phylogenetic analyses show that the three populations of S. hirsutus of Venezuela form an ancestral and monophyletic subclade supported by high bootstrap values and significant genetic distance between subclade within the S. hirsutus. Besides, the existence of two lineages suggests two subspecies, S. hirsutus hirsutus from Venezuela, and S. hirsutus mexicanus from Mexico-Central America, but, both species need formal description. Rev. Biol. Trop. 59 (2): 795-807. Epub 2011 June 01.

Recientes estudios filogenéticos basados en la secuencia del gen del citocromo b, han determinado que la especie conocida históricamente como Sigmodon hispidus (Rodentia) en Suramérica incluye una especie S. hirsutus de origen parafilético. El objetivo de este estudio fue probar la hipótesis de que las poblaciones de Venezuela, representan la forma sensu estricto, los haplotipos ancestrales y una subespecie monofilética. La metodología consistió en un análisis cladístico y cálculos de distancia genética, a partir de secuencias de citocromo b en 12 individuos de tres localidades en Venezuela que pertenecen a diferentes regiones biogeográficas, y a su vez compararlas con las dos secuencias disponibles en Genbank de especies del género Sigmodon. Los análisis filogenéticos indican que las tres poblaciones de S. hirustus de Venezuela forman un subclado ancestral y monofilético con el apoyo de valores de bootstrap altos y con significativa distancia genética, entre subclados dentro de S. hirsutus. La existencia de dos subclados dentro de S. hirsutus sugiere dos subespecies, S. hirsutus hirsutus en Venezuela y S. hirsutus mexicanus en México y Centroamérica. Sin embargo, ambas subespecies necesitan una descripción formal.

Distribution patterns of Neotropical primates (Platyrrhini) based on Parsimony Analysis of Endemicity

The Parsimony Analysis of Endemicity (PAE) is a method of historical biogeography that is used for detecting and connecting areas of endemism. Based on data on the distribution of Neotropical primates, we constructed matrices using quadrats, interfluvial regions and pre-determinated areas of endemism described for avians as Operative Geographic Units (OGUs). We codified the absence of a species from an OGU as 0 (zero) and its presence as 1 (one). A hypothetical area with a complete absence of primate species was used as outgroup to root the trees. All three analyses resulted in similar groupings of areas of endemism, which match the distribution of biomes in the Neotropical region. One area includes Central America and the extreme Northwest of South America, other the Amazon basin, and another the Atlantic Forest, Caatinga, Cerrado and Chaco.

A Análise de Parcimônia de Endemismo (PAE) é um método da biogeografia histórica que é usado para detectar e conectar áreas de endemismo. Baseando-se em dados de distribuição de primatas Neotropicais, construíram-se matrizes de dados utilizando-se quadrículas, regiões entre rios e áreas de endemismo pré-determinadas para aves como Unidades Geográficas Operacionais (OGUs). Codificou-se a ausência da espécie na OGU como 0 (zero) e a presença como 1 (um). Uma área hipotética com ausência total de espécies de primatas foi usada como grupo externo para polarização. Todas as três análises resultaram em grupos similares de áreas de endemismo, coincidindo com a distribuição de biomas na região Neotropical: uma área incluindo a América Central e o extremo Noroeste da América do Sul; outra, a Bacia Amazônica; e, uma terceira, a Mata Atlântica, Caatinga, Cerrado e Chaco.