Milton Gallardo Narcisi. 2017. Evolución. El curso de la vida. Primera edición electrónica

Se trata de la versión corregida y aumentada de la edición en papel del libro del biólogo chileno Milton H. Gallardo Narcisi, que la Facultad de Ciencias de la Universidad Austral de Chile pone a disposición de la comunidad científica de habla hispana.Es una obra de acceso abierto y distribución gratuita que se descarga de http://sitiosciencias.uach.cl/EvolucionElCursodelaVida2017.pdf. Consta de 730 páginas y ha sido organizada en dos grandes partes

The genus <i>Chlamydotheca</i> Saussure (Crustacea: Ostracoda) in northeastern Argentina

The genus Chlamydotheca Saussure, 1858 is a typical representative of the Neotropical ostracod fauna that occupies lotic and lentic environments including temporary and  permanent ponds. Up to the present, four species have been recorded in Argentina: C. iheringi (Sars), C. incisa (Claus) and C. leuckarti (Claus), and C. symmetrica (Vávra). Temporary and permanent ponds of this region were sampled for ostracods, using a fine mesh net. Three species belonging to the genus Chlamydotheca were collected of which C. arcuata (Sars) is recorded for first time for the Chacoan region. Limb morphology was studied under light microscope and line drawings were made using camera lucida. Valves were photographed under scanning electron microscope and redescriptions of C. arcuata and C. iheringi are provided and distributional aspects of the species sampled are discussed.Facultad de Ciencias Naturales y MuseoConsejo Nacional de Investigaciones Científicas y Técnica

Postembryonic development of nonmarine ostracod <i>Chlamydotheca arcuata</i> (Sars, 1901) (Crustacea: Ostracoda), reared in the laboratory

We describe here 8 instars (from A-8 through A-1) of the postembryonic development of the Cyprididae Chlamydotheca arcuata (Sars, 1901) from hatching to sexually mature individuals. To study the development of this species, cultures of adult parthenogenetic female specimens were established and maintained in the laboratory. The ostracod specimens were collected from temporary ponds and streams in Buenos Aires Province, Argentina. This report provides a description of the chaetotaxy of each limb along with detailed illustrations. Photographs of eggs and carapaces were taken using scanning electron microscopy. The complete development of Chlamydotheca arcuata lasted between 80 and 90 days. In the first instars, the active swimmers are characterized by carapaces that have a greater height in front of the first half of the maximum length and taper toward the rear end to become pointed. The appearance and numbers of the sensory setae on the carapace increase in the latest instars.Facultad de Ciencias Naturales y Muse

Milton Gallardo Narcisi. 2017. <i>Evolución. El curso de la Vida</i> : Primera edición electrónica

Se trata de la versión corregida y aumentada de la edición en papel del libro del biólogo chileno Milton H. Gallardo Narcisi, que la Facultad de Ciencias de la Universidad Austral de Chile pone a disposición de la comunidad científica de habla hispana.Facultad de Ciencias Naturales y Muse

A new species of Keysercypria Karanovic (Crustacea: Ostracoda) from Argentina

In her revision on Recent Cyclocypridinae, Karanovic (2011) erected the new genus Keysercypria, endemic of the Neotropical Realm. The aim of this study is to describe and illustrate a new species within the genus recorded from the lower Parana region, according to the recently proposed division of the world freshwater ecosystems (www.feow.org). The new species represents the most southern record of the genus. Samples were taken in December 2008 from a temporary pond covered with macrophytes in Buenos Aires Province, Argentina. The material was collected with a fine-meshed (0.25 mm) hand net. The ostracods were then transferred to 70% alcohol for permanent storage. The specimens were dissected under a stereomicroscope immersed in polyvinyllactophenol. The limb morphology was studied under the light microscope and line drawings were made with the help of Zeiss, Standard 25 stereomicroscope with camera lucida.Fil: Diaz, Analia Roxana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Lopretto, Estela Celia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin

The genus <i>Chlamydotheca</i> Saussure (Crustacea: Ostracoda) in northeastern Argentina

The genus Chlamydotheca Saussure, 1858 is a typical representative of the Neotropical ostracod fauna that occupies lotic and lentic environments including temporary and  permanent ponds. Up to the present, four species have been recorded in Argentina: C. iheringi (Sars), C. incisa (Claus) and C. leuckarti (Claus), and C. symmetrica (Vávra). Temporary and permanent ponds of this region were sampled for ostracods, using a fine mesh net. Three species belonging to the genus Chlamydotheca were collected of which C. arcuata (Sars) is recorded for first time for the Chacoan region. Limb morphology was studied under light microscope and line drawings were made using camera lucida. Valves were photographed under scanning electron microscope and redescriptions of C. arcuata and C. iheringi are provided and distributional aspects of the species sampled are discussed.Facultad de Ciencias Naturales y MuseoConsejo Nacional de Investigaciones Científicas y Técnica

The genus <i>Chlamydotheca</i> Saussure (Crustacea: Ostracoda) in northeastern Argentina

The genus Chlamydotheca Saussure, 1858 is a typical representative of the Neotropical ostracod fauna that occupies lotic and lentic environments including temporary and  permanent ponds. Up to the present, four species have been recorded in Argentina: C. iheringi (Sars), C. incisa (Claus) and C. leuckarti (Claus), and C. symmetrica (Vávra). Temporary and permanent ponds of this region were sampled for ostracods, using a fine mesh net. Three species belonging to the genus Chlamydotheca were collected of which C. arcuata (Sars) is recorded for first time for the Chacoan region. Limb morphology was studied under light microscope and line drawings were made using camera lucida. Valves were photographed under scanning electron microscope and redescriptions of C. arcuata and C. iheringi are provided and distributional aspects of the species sampled are discussed.Facultad de Ciencias Naturales y MuseoConsejo Nacional de Investigaciones Científicas y Técnica

Ciliados (Protozoa) de sedimentos secos de una charca temporaria de la Argentina

Temporary ponds represent special environments that are inhabited by organisms adapted to changing environmental conditions. Ciliates are able to survive complete loss of water in these transient habitats through cyst formation. Nevertheless, ciliates from the Neotropical region in general have been poorly studied through the use of modern techniques. The main goal of this study is to describe the ciliates developing in dried sediments of a temporary pond from the Buenos Aires Province, Argentina through samplings that were performed during the period 2003-2005. Soil samples were obtained during drought phases and rewetted in laboratory, in order to establish raw and enriched cultures. Ciliates were then studied both in vivo and after  impregnation with protargol. In this study, we present four new records for Argentina (Gonostomum affine (Stein, 1859) Sterki, 1878, Stylonychia bifaria (Stokes, 1887) Berger, 1999, Pleurotricha lanceolata (Ehrenberg, 1835) Stein, 1859, Meseres  corlissi Petz and Foissner, 1992), one more for South America (Blepharisma americanum (Suzuki, 1954) Hirshfield, Isquith and Bhandary, 1965), and two for the Neotropical Realm (Gonostomum strenuum (Engelmann, 1862) Sterki, 1878, Stylonychia lemnae Ammermann and Schlegel, 1983).Los cuerpos de agua temporarios son ambientes particulares que se encuentran habitados por organismos adaptados a condiciones fl uctuantes. Los ciliados son capaces de sobrevivir a la pérdida completa de agua del ambiente gracias a la formación de estructuras de resistencia. Por otra parte, los ciliados de la región Neotropical han sido poco investigados con técnicas modernas. El objetivo de este estudio es referir los ciliados que se desarrollaron a partir de los sedimentos secos de una charca temporaria de la provincia de Buenos Aires, Argentina, en la que se realizaron muestreos durante el período 2003-2005. Las muestras de suelo fueron obtenidas durante las fases de sequía y luego resuspendidas en el laboratorio para realizar cultivos naturales y enriquecidos. Los ciliados fueron estudiados in vivo y luego de la impregnación argéntica con protargol. En este trabajo se presentan 4 nuevos registros de especies para la fauna de ciliados de la Argentina (Gonostomum affi ne (Stein, 1859) Sterki, 1878, Stylonychia bifaria (Stokes, 1887) Berger, 1999, Pleurotricha lanceolata (Ehrenberg, 1835) Stein, 1859, Meseres corlissi Petz and Foissner, 1992), 1 para América del Sur (Blepharisma americanum (Suzuki, 1954) Hirshfi eld, Isquith and Bhandary, 1965) y 2 para la región Neotropical (Gonostomum strenuum (Engelmann, 1862) Sterki, 1878, Stylonychia lemnae Ammermann and Schlegel, 1983).Fil: Kuppers, Gabriela Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Claps, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Lopretto, Estela Celia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Postembryonic development of nonmarine ostracod <i>Chlamydotheca arcuata</i> (Sars, 1901) (Crustacea: Ostracoda), reared in the laboratory

We describe here 8 instars (from A-8 through A-1) of the postembryonic development of the Cyprididae Chlamydotheca arcuata (Sars, 1901) from hatching to sexually mature individuals. To study the development of this species, cultures of adult parthenogenetic female specimens were established and maintained in the laboratory. The ostracod specimens were collected from temporary ponds and streams in Buenos Aires Province, Argentina. This report provides a description of the chaetotaxy of each limb along with detailed illustrations. Photographs of eggs and carapaces were taken using scanning electron microscopy. The complete development of Chlamydotheca arcuata lasted between 80 and 90 days. In the first instars, the active swimmers are characterized by carapaces that have a greater height in front of the first half of the maximum length and taper toward the rear end to become pointed. The appearance and numbers of the sensory setae on the carapace increase in the latest instars.Facultad de Ciencias Naturales y Muse

Evolución biológica, egoísmo y cooperación

This contribution aims reviews of approaches related to levels of natural selection and key events that took place during the 1960s, including the rejection of group selection and development of alternative theoretical framework to explain the evolution of behaviors intended cooperative and altruistic. It shows how such concepts have revived based on a more care-ful formulation and how the theory of multilevel selection (including group selection) provides a theoretical basis for sociobiology in the future, once its past has been understood properly.En esta contribución se pretende una revisión de enfoques referidos a niveles de selección natural y de acontecimientos fundamentales que tuvie-ron lugar durante la década de 1960, incluyendo el rechazo de la selección de grupo y el desarrollo de marcos teóricos alternativos para explicar la evolución de los comportamientos cooperativos y altruistas. Se indica có-mo han revivido tales conceptos en base a una formulación más cuidadosa y cómo la teoría de la selección multinivel (incluyendo la selección de gru-po) proporciona una base teórica para la sociobiología en el futuro, una vez que su pasado se entienda adecuadamente.Facultad de Ciencias Naturales y Muse