fernando lobo

Andean orogeny is one of the main factors that promoted the diversification of many groups of animals. Among them are the lizards of the Liolaemidae family and. within this, Liolaemus is the genus with the most described species up to date, with approximately 277 species. One of the groups within the genus is the Liolaemus ornatus group, distributed in the south of Central Andes mountain chain. In this work, we describe a new species belonging to the L. ornatus group, using an integrative approach, analyzing both morphological (lepidosis, morphometric, coloration and hemipenes characters) and molecular evidence. We made a divergence analysis of the representatives of the L. ornatus group. Furthermore, we correlated the ages of the geological events with the distribution areas for the L. ornatus group. This newly described species shows character states (morphological and molecular) that allow its clear distinction from the other members of the L. ornatus group, as well as from the r...

Abstract. Liolaemus duellmani is a poorly known, microendemic lizard described from southwestern Mendoza, Argentina, representing the southernmost distribution of the Liolaemus montanus species group. We report the rediscovery of the species after 43 years, presenting the fifth voucher specimen and the second female of L. duellmani. Data on external morphology, activity, and color photographs are included, and the geographic coordinates of the type locality are discussed.

The northernmost distributed group of lizards belonging to Phymaturus occurs in rocky outcrops of the Puna region between 3600-4200 m in Argentina. In a recent phylogenetic study based on morphological and genetic information, the monophyly of this small lineage was corroborated. This group is formed by Phymaturus antofagastensis, P. laurenti, P. denotatus, P. mallimaccii and a population of uncertain taxonomic status until the present study. After obtaining new samples and observations, we described a new species belonging to this lineage that is known only from Sierra de Fiambalá, being the species of Phymaturus living at the highest elevation ever recorded (4500 m). Males have a homogeneous yellow dorsum and lack melanic coloration over their heads, a phenomenon found in males of most species of the palluma group. We provide a detailed diagnosis, including characters from the squamation, coloration and significant differences found among continuous characters (ANOVA). Furthermore...

VARIACIÓN MORFOLÓGICA EN EL ESQUELETO DE LIOLAEMUS (IGUANIA: LIOLAEMIDAE). BÚSQUEDA Y DESCRIPCIÓN DE CARACTERES FERNANDO LOBO & CRISTIAN ABDALA 2 1. Cátedra de Anatomía Comparada (www.unsa.edu.ar/acunsa). Facultad de Cs. Naturales, Universidad Nacional de Salta. Avda. Bolivia 5150, 4.400 Salta, Argentina. E-mail: flobo@unsa.edu.ar. 2. Instituto de Herpetología, Fundación Miguel Lillo. CONICET. Miguel Lillo 251, 4.000 Tucumán, Argentina. E-mail: popper@tucbbs.com.ar RESUMEN. Estudiamos los esqueletos teñidos y transparentados como también secos de veinticuatro especies pertenecientes a los principales clados de Liolaemus (grupos L. kingii L. archeforus, L. lineomaculatus, L. chiliensis, L. signifer, L. boulengeri y L. wiegmannii de acuerdo con la taxonomía de Etheridge, 1995). Pudimos describir variación en la morfología, proporciones y otras carácterísticas que pueden definirse como caracteres. Los caracteres descriptos en este estudio incluyen variación en los cartílagos de las cos...

Different studies suggest that reproductive characters evolve faster than non-reproductive characters. Males in the order Squamata have paired copulatory organs called hemipenes, with high morphological diversity, including differences in size, shape, and ornamentation. Some studies in the species-rich lizard genus, Anolis suggest that genital traits evolve faster than the rest of the body. However, these studies were made considering only a few traits, across a wide phylogeny, without considering species relatedness, which may inflate differences in evolutionary rates. Here, we study two phylogenetic distantly related lizard groups, which differ in the number of species, but have similar divergence times. We evaluate as follows: (1) evolutionary rate, models of evolution and phylogenetic signal among the different genital and non-genital traits; (2) which kind of traits (genital and non-genital) are divergent across sister species and (3) whether the species-rich group shows a faster rate of trait change. We studied 24 Liolaemus lizard species, belonging to two monophyletic groups that differ in species number: L. elongatus' clade, which has more species than L. lineomaculatus' clade. We studied 20 different traits (9 genital and 11 non-genital) and calculated their phylogenetic signal, evolutionary rate of change and models that best explain the evolutionary change. Our results show that: (1) in general, genital traits evolve faster than non-genital ones in both groups, and both phylogenetic signal and best evolutionary model vary depending on the trait. (2) Genital traits diverged more among sister species within the L. li-neomaculatus group, but within the L. elongatus group, both sets of traits show similar degrees of divergence. Finally, (3) the species-rich group (L. elongatus), has the highest genital evolutionary rate but also the highest non-genital evolutionary rate.

Some lizard species modulate the use of a retreat site based on the presence of scents from other individuals, behavior that requires scent recognition. Here, we investigated if two congeneric and syntopic lizards (adults of Liolaemus coeruleus and juveniles of L. ceii, which can be found sharing retreat sites in the wild) discriminate scents from each other during the pre-hibernation period. If the presence of heterospecific scents modulates sharing retreat sites, species would discriminate each other's scents. Lizards were individually exposed to four treatments, which were enclosures with scents of (1) from the focal individual (own); (2) a conspecific of the same sex as the focal lizard; (3) a heterospecific of the same sex as the focal lizard; and (4) a control (i.e., enclosure with a clean substrate). Our results suggest that there is no heterospecific recognition. This finding was not due to an inability to chemo-assess scents, since both species exhibited self-recognition (recognition of their own scents) and juveniles of L. ceii also showed conspecific recognition. Although it might be advantageous for species to share retreat sites, chemical recognition of heterospecific scents does not modulate this behavior in these syntopic species. Resumen. Algunas especies de lagartos modulan el uso de un sitio de retiro basados en la presencia de rastros de olores de otros individuos presentes en el sitio, comportamiento que requiere reconocimiento de estos rastros de olores. En este trabajo, investigamos dos lagartos cogenéricos y sintópicos (adultos de Liolaemus coeruleus y juveniles de L. ceii, los cuales pueden ser encontrados en la naturaleza compartiendo sitios de retiro), si discriminan los rastros de olores de cada uno de ellos durante el periodo pre-invernal. Si la presencia de rastros de olores heteroespecíficos modula el compartir sitios de retiro, ambas especies discriminarían los rastros de olores entre sí. Los lagartos fueron expuestos individualmente a cuatro tratamientos, los cuales fueron los recintos con diferentes olores de: (1) propio, del individuo focal; (2) conespecífico del mismo sexo que el lagarto focal; (3) heteroespecífico del mismo sexo que el focal y (4) control, i.e., un recinto con substrato limpio. Nuestros resultados sugieren que no habría presencia de reconocimiento químico heteroespecífico, lo cual, no es consecuencia de una incapacidad para evaluar rastros químicos, puesto que ambas especies exhibieron auto reconocimiento (reconocimiento de sus rastros de olores propios) y los juveniles de L. ceii además exhibieron reconocimiento de sus conespecíficos. A pesar de que estas especies puedan beneficiarse de compartir sitios de refugio, aparentemente, el reconocimiento químico de los rastros de heterospecíficos, no modularía el sitio de refugio compartido por estas especies sintópicas.

Phymaturus is a clade of lizards that occurs at moderate to high elevations in western Argentina and the adjacent central region of Chile, as well as in various volcanic plateaus of the Patagonian region of Argentina. This genus had previously been divided into two groups: the patagonicus and the palluma groups. In this study, we analyzed relationships within the patagonicus group. The data set was built for 23 species plus nine other terminal taxa of undetermined taxonomic status. In total, 10,631 bp (ND4, Cytb, 12S, COI, five protein coding nuclear genes and seven anonymous nuclear loci) and 254 morphological characters were analyzed in a combined data set for 35 ingroup taxa and nine outgroups. We also ran separate DNA sequence and morphological data sets. We identified four main clades, and revealed congruencies and incongruences with previous studies. The indistinctus clade is recovered as the most basal within the patagonicus group in the strict parsimony analysis, while the so-muncurensis clade is the most basal under Bayesian inference. The previously recovered calcogaster clade resulted paraphyletic in both analyses and part of their species are included in a redefined somuncurensis clade. We found low support at basal nodes provoked in part by contradictory evidence shown by rogue taxa. We show the phylo-genetic information given by each partition/marker and how they contribute to relationships found in the total evidence analysis. We discuss the phylogenetic position of Phymaturus manuelae, Phymaturus tenebrosus, and Phymaturus patagonicus.

In reptiles, many lipid reserve structures were recognized, and different patterns of storage and utilization of lipids have been identified. In this study, a population of Liolaemus koslowskyi was studied to analyze the diversity and functioning of the lipid reserve structures. The specific objectives were to identify the main lipid reserve structures, and to describe their seasonal patterns; to study sexual and seasonal variations of the reserve structures; and to analyze the relation between seasonal patterns of such reserves with the sexual cycle and other biological aspects. Individuals of both sexes collected at five different times of the year were analyzed. The abdominal fat bodies, livers, tails, fat deposits of the lateral folds of the neck, the fat bodies of the axillary region and gonads were weighted. The fat content of livers, tails and neck fat reserves were determined through the extraction in a Soxhlet device. The volume of the ovaries, oviductal oocytes and testicles, and the average surface and thickness of the epididymides were estimated. The abdominal fat bodies and the tail-extracted fats were the main lipid reserves. In general, females showed higher lipid contents, and significant seasonal variations in weight and lipid content in both sex were found, while seasonal variations in the liver fresh weight and liver fat content were found only in males. The axillar and neck fats deposits probably function as auxiliary reserves, and the caudal autotomy did not significantly affect tail fat content. The sexual cycles were synchronic in both sexes.

The number of species of the genus Phymaturus has increased consistently since 1995, when only 10 species had been described. Over the last two decades, this number has risen to 46. This group of lizards is characterized by a flattened body and spiny tail; they are viviparous and herbivorous and inhabit rocky regions, using crevices as refuges. For the present study, an integrative taxonomy approach was used with the aim of rigorously assessing the taxonomic status of a population occupying the Auca Mahuida volcanic field. Evidence from genetics, morphology, and biogeography suggests that this population is a separate lineage from all described species. This new species can be distinguished from close relatives by a longitudinal white dorsal line along the midline at the base of the tail. Special emphasis was put on determining if this taxon presented differences from the nearest relatives of the palluma group: P. roigorum and P. tromen. Consistent differences were found. Resumen. El número de especies del género Phymaturus se ha incrementado constantemente desde 1995, cuando sólo diez especies habían sido descriptas. En las últimas dos décadas, este número se incrementó a 46. Este grupo de lagartos se caracteriza por tener un cuerpo ancho y achatado, una cola con espinas, ser herbívoros y vivíparos y habitar regiones rocosas, usando grietas como refugio. Para este trabajo se tomó una perspectiva desde la taxonomía integrativa para poder llegar a una evaluación rigurosa sobre el estatus taxonómico de la población que ocupa el campo volcánico Auca Mahuida. Evidencias genéticas, morfológicas y biogeográficas sugieren que esta población es un linaje separado de todas las especies descriptas hasta el momento. Esta nueva especie se distingue por una línea longitudinal en la línea media dorsal en la base de la cola. Se puso especial énfasis en determinar si este taxón presenta diferencias con los parientes más cercanos del grupo de P. palluma: P. roigorum y P. tromen. Se encontraron diferencias consistentes.

With 36 species and at least nine potentially independent lineages (not formally described yet) occurring mostly in theAndes and adjacent Patagonia and Puna plateau areas, Phymaturus lizards represent one of the most endemic vertebrategroups of the arid southwestern region of South America. Phylogenetic relationships among species of Phymaturus areinferred using mainly a morphological data set of 206 characters. Also available sequences of mitochondrial DNA for sev-en terminals were added for a total evidence analysis. Most information is included in the discrete characters block; mostcharacters involve color pattern, osteology and squamation. Continuous characters were taken from body proportions,squamation and skeletons. Among morphological data, binary polymorphic characters were analyzed applying the scaledcoding criteria. Continuous characters were entered in the analysis using standardized ranges, a method that allows a sim-ple optimization to estimate distances/costs avoiding...

In living organisms with sexual reproduction, the presence of sexual size dimorphism (SSD) is common. The main explanations for this phenomenon are based on sexual selection or the fecundity advantage hypothesis (natural selection). Here, we tested Rensch's rule in species of the viviparous lizard genus Phymaturus; additionally, we tested if there is a pattern of sexual size dimorphism or if it depends upon other morphological traits. We found no evidence for Rensch's rule in these lizards. After testing for multiple or single regime evolutionary models, we found that body size most likely evolved under multi-regime Ornstein-Uhlenbeck evolutionary model; the same was observed for abdomen width in females, a fecundity advantage hypothesis trait. For species with female biased SSD there is a positive relationship between snout-vent length and width of the belly, supporting the fecundity advantage hypothesis. Additionally, the relationship between brood size and brood mass with body size and body mass (respectively) were positive giving strength to the fecundity advantage hypothesis. Finally, our results show males did not show a clear pattern in relation to the sexual selection hypothesis, probably because sexual selection is a complex aspect that involves behavior and color. On the other hand, female body size and reproductive output are related to mean seasonal air temperature and its combination with mean annual air temperature in an evolutionary fashion framework, such as fecundity advantage hypothesis in these lizards.

The lizard genus Liolaemus includes over 160 species of which almost half are in the chiliensis group. Although some researchers have attempted to define smaller species groups within this large clade, the relationships among the taxa within the group as a whole remain ...

Phymaturus comprises 44 species mainly distributed along the south-west of South America on both sides of the Andes. In this study we present a phylogenetic analysis of Phymaturus of the palluma group, one of its two large clades, including almost all described species. This analysis duplicates the number of in-group taxa compared with previous contributions. We performed a total-evidence analysis, combining molecular and morphological characters: sequencing fragments of cytochome b (cytb), 12S, and ND4, for all terminals; describing 45 new morphological characters; and incorporating all DNA sequences available from GenBank. Separate analyses of morphology and DNA partitions are presented and discussed in detail. Seven subclades are recognized here. We named three new subclades and redefined another, found to be paraphyletic. In order to recognize lineages within the traditional Phymaturus palluma group we proposed to treat it as a natural group, containing within it the ranks of clade, subclade, and lineages, respectively. The palluma group is composed by the vociferator and the bibronii clades. The vociferator clade, composed of Chilean and Argentinean species, would be the most basal in the group. Within the bibronii clade, the roigorum subclade includes the Phymaturus verdugo lineage, whereas the mallimaccii subclade would consist of 13 terminal taxa, for which three Chilean species have been added. In this study, morphological apomorphies are identified for all clades and the evolution of ‘male head melanism’ is discussed.

The lizard genus Liolaemus includes over 160 species of which almost half are in the chiliensis group. Although some researchers have attempted to define smaller species groups within this large clade, the relationships among the taxa within the group as a whole remain ...

We provide a critical review of a recent taxonomic revision of Chilean Liolaemus lizards (Iguania: Liolaemidae) by Pincheira-Donoso and Núñez (2005) and a recent paper (PincheiraDonoso et al. 2008), which proposed several new taxonomic and phylogenetic arrangements. We document fundamental problems with many of the proposed taxonomic revisions in both publications, which if followed, could lead to serious taxonomic confusion. In Pincheira-Donoso and Núñez (2005) a subgeneric classification is erected, which was produced by outdated methods (phenetic analyses), cannot be replicated (no matrix is presented), and is taxonomically untenable (some of the subgenera are nested within other subgenera). Most of the taxonomic groups that are proposed have been previously proposed, albeit differently constituted, yet often previous research is not given attribution; when findings are different, the research of others is either overlooked or dismissed without comment. The diagnoses of species and subspecies (including several newly proposed taxa) are often written in an authoritative manner (without supporting data or information), making them insufficient for distinguishing the focal taxon from others belonging to the same group, finally leading to uncertainty regarding the validity of several of the newly proposed taxa, combinations, or synonymies. We also describe less egregious errors of omission and commission. In Pincheira-Donoso et al. (2008), most of the proposals follow the Pincheira-Donoso and Núñez (2005) revisions, some species are allocated to groups without consistent cladistic support and other proposed relationships are based on incomplete evidence from other studies dismissing the limitations of the arrangement. Critical species are not identified in a list of material examined. Finally, Pincheira-Donoso et al. (2008) present a somewhat outdated and biased discussion of the relative value of using molecules or morphology in systematics. In light of these limitations, and in an effort to stabilize and prevent further taxonomic confusion, we provide an updated phylogenetic classification of the currently recognized lizards of the family Liolaemidae (Ctenoblepharys, Liolaemus, and Phymaturus), which is based on a consensus of studies published since the first phylogenetic major revision of the clade in 1995.

This paper proposes a more comprehensive evaluation methodology to measure the usability and user experience qualities of accessible synchronous computer-mediated communication applications. The methodology goes beyond current practices by evaluating how the interaction between a user and a product influences the user experience of those at the other endpoint of the communication channel. A major contribution is given with the proposal of a user test where one of the participants tries to guess whether the other participant has a disability or not. The proposed test is inspired in the Turing Test, and is a consequence of user requirements elicited from a group of individuals with motor and speech disabilities. These ideas are tested and validated with two examples of synchronous communication applications.

ABSTRACT We provide descriptions for two new cryptic species belonging to the Liolaemus alticolor group from northern Argentina and northeastern Chile. The new species were previously considered conspecific with either Liolaemus walkeri in northeastern Chile or L. alticolor in northwestern Argentina and adjacent Chile. However, the new species differ from these taxa, and all other members of the alticolor group, in a number of characteristics. Liolaemus chaltin n. sp. differs from L. alticolor from the type locality (Tiahuanaco, Bolivia) in the following ways: this new species has a larger body size; a fragmented vertebral stripe; and a pigmented subocular (white in L. alticolor), and is one of just three members of the alticolor group that is oviparous. Liolaemus puna n. sp. differs from all other members of the alticolor group in that male L. puna lack paravertebral markings and dorsolateral and vertebral stripes. Females, however, are similar to other members of the alticolor group but can be distinguished from them by several meristic characters. Liolaemus puna is widely distributed throughout the high-elevation (3680–4400 m) Puna regions (a flat or gently sloping steppe dominated by perennial bunch grasses and small shrubs) in northwestern Argentina and northeastern Chile. Liolaemus chaltin is known only from the Puna of central Jujuy Province, Argentina (3400–3750 m). Based on examina-tions of the type series of L. alticolor and L. walkeri, we determined that virtually all northern Chilean populations of Liolaemus previously considered to belong to either of these two species should be assigned to L. puna. Thus, the range of L. alticolor is restricted to Bolivia and southern Perú , and the range of L. walkeri is restricted to central and southern Andean Perú. Liolaemus chaltin is oviparous, and L. puna is viviparous, and because both are morphologically similar to L. alticolor, some inves-tigators have suggested that some populations of L. alticolor may be reproductive bimodal. Our studies, however, indicate that these populations represent sympatric populations of the cryptic species described herein. A diagnostic key is provided for the currently recognized members of the alticolor group. En este trabajo presentamos la descripció n de dos nuevas especies pertenecientes al grupo Liolaemus alticolor del norte de Argentina y nordeste de Chile. Las nuevas especies fueron consideradas previamente como conespecíficas con Liolaemus wal-keri en el noreste de Chile, o L. alticolor en el noroeste de Argentina y areas limi-tantes de Chile. En efecto, las nuevas especies difieren de estos taxa y de todos los otros miembros del grupo alticolor en varios caracteres morfoló gicos y bioló gicos. Liolaemus chaltin n. sp. difiere de L. alticolor de la localidad tipo (Tiahuanaco, Bo-livia) de la siguiente forma: es de mayor tamaño, la línea vertebral fragmentada, la subocular pigmentada, y es uno de los tres miembros del grupo que es ovíparo. Liolaemus puna n. sp. difiere de todos los otros miembros del grupo alticolor en que los machos de esta especie carecen de bandas dorsolaterales, manchas paraverte-brales, y de linea vertebral. Las hembras son similares a las de las restantes especies del grupo aunque pueden diferenciarse mediante diferentes caracteres meristicos. Liolaemus puna está ampliamente distribuido en las regiones de considerable ele-vació n (3680–4400) de la Puna (una estepa carente de arboles y caracterizada por la presencia de pastizales perennes y pequeños arbustos) en el norte de Argentina y noreste de Chile. Liolaemus chaltin es conocido solamente en la Puna de la región central y norte de la provincia de Jujuy, Argentina (3400–3750 m). Basados en el estudio de las series tipo de L. alticolor y L. walkeri, hemos determinado que casi todas las poblaciones del norte de Chile de Liolaemus previamente consideradas como una u otra de esas dos especies deberían ser asignadas a L. puna. De este modo el rango de L. alticolor se limita a Bolivia y sur del Perú, y el rango de L. walkeri esta limitado a los Andes del sur y centro de Perú. Liolaemus chaltin es

This paper describes the application of a real coded genetic algorithm (GA) to align two or more 2-D images by means of image registration. The proposed search strategy is a transformation parameters-based approach involving the affine transform. The real coded GA uses Simulated Binary Crossover (SBX), a parent-centric recombination operator that has shown to deliver a good performance in many optimization problems in the continuous domain. In addition, we propose a new technique for matching points between a warped and static images by using a randomized ordering when visiting the points during the matching procedure. This new technique makes the evaluation of the objective function somewhat noisy, but GAs and other population-based search algorithms have been shown to cope well with noisy fitness evaluations. The results obtained are competitive to those obtained by state-of-the-art classical methods in image registration, confirming the usefulness of the proposed noisy objective function and the suitability of SBX as a recombination operator for this type of problem.

Due to increasing population, and human activities on land to meet various de-mands, land uses are being continuously changed without a clear and logical planning with any attention to their long term environmental impacts. Thus affecting the nat-ural balance of the ...

Compressed Introns in a Linkage Learning Genetic Algorithm ... Fernando G. Lobo Kalyanmoy Deb David E. Goldberg Georges R. Harik Liwei Wang ... Illinois Genetic Algorithms Laboratory Department of General Engineering University of Illinois at Urbana-Champaign 117 ...