BOOKS by Cristina Lopez-Gallego
Two major lineages of beetles inhabit cycad cones in the New World: weevils (Curculionoidea) in t... more Two major lineages of beetles inhabit cycad cones in the New World: weevils (Curculionoidea) in the subtribe Allocorynina, including the genera Notorhopalotria Tang and O'Brien, Parallocorynus Voss, Protocorynus O'Brien and Tang and Rhopalotria Chevrolat, and beetles in the family Erotylidae, including the genus Pharaxonotha Reitter. Analysis of the 16S ribosomal RNA (rRNA) mitochondrial gene as well as cladistic analysis of morphological characters of the weevils indicate four major radiations, with a probable origin on the cycad genus Dioon Lindl. and comparatively recent host shifts onto Zamia L. Analysis of the 16S rRNA gene for erotylid beetles indicates that an undescribed genus restricted to New World Ceratozamia Brongn. is the most early-diverging clade, and this lineage is sister to a large radiation of the genus Pharaxonotha onto Zamia, with apparent host shifts onto Dioon and Ceratozamia. Analysis of beetles are in accord with current models of continental drift in the Caribbean basin, support some proposed species groupings of cycads, but not others, and suggest that pollinator type may impact population genetic structure in their host cycads.
Papers by Cristina Lopez-Gallego
Zamia paucifoliolata, a new cycad species from the Pacific lowlands of Valle del Cauca, Colombia,... more Zamia paucifoliolata, a new cycad species from the Pacific lowlands of Valle del Cauca, Colombia, is described and illustrated. It is distinguished from other species of Zamia by having an underground stem typically bearing large solitary leaves with eighteen or fewer leaflets, villous strobilar axes, microsporangia borne on both the abaxial and adaxial side of microsporophylls, and seeds that are longer than 18 mm. It is compared to Z. pyrophylla, Z. cunaria, and Z. ipetiensis, species which it most closely resembles. Resumen Se describe y se ilustra Zamia paucifoliolata, una nueva especie de cícada de las tierras bajas del Pacífico Colombiano del Valle del Cauca. Se distingue de otras especies de Zamia por su tallo subterráneo típicamente cargando hojas solitarias con 18 folíolos o menos, ejes estrobilares vellosos, presencia de microesporangios en el lado abaxial y adaxial de los microesporofilos, y semillas de mas de 18 mm de longitud. Se compara con Z. pyrophylla, Z. cunaria, y Z. ipetiensis, las especies a las que más se asemeja. Palabras clave: Chocó biogeográfico, sistemática, taxonomía Introduction With 78 species, the neotropical genus Zamia Linnaeus (1763: 1659) is the most speciose and broadly distributed genus in the New World (Calonje et al. 2018). Colombia hosts over a quarter of all Zamia species, making it the most species-rich country for the genus. A considerable amount of academic and taxonomic research on Colombian zamias has taken place over the last decade, including several new species descriptions (Lindstrom & Idarraga 2009, Calonje et al. 2010, Calonje et al. 2011, Calonje et al. 2012a, Stevenson et al. 2018) as well as taxonomic revisions (Lindstrom 2009, Calonje et al. 2012b, Calonje et al. 2015). Despite these recent and significant advances in Colombian Zamia systematics, additional research is still required, because several species remain undescribed or poorly understood, especially in the Amazonian region. A visit in 2009 by the first author to the CUVC herbarium (Cali, Colombia) revealed an enigmatic Zamia specimen (Gil Cardona et al. 577) collected in 2002 in coastal forests of the Buenaventura municipality in Valle del Cauca, Colombia. The specimen consisted of a mature seed strobilus without any accompanying vegetative material. The strobilus had an extremely long peduncle unlike any other species known in the Valle del Cauca, but somewhat resembled that of Chocoan endemic species Z. pyrophylla Calonje et al. (2010: 80), albeit with much larger seeds. Recent expeditions to this region has revealed this enigmatic taxon to be an undescribed species, which we formally describe below. The new species has morphological affinities
Because cycad species are long lived and in many cases populations are small, studies of populati... more Because cycad species are long lived and in many cases populations are small, studies of population dynamics are challenging. In this paper, I pres ent examples of field studies complemented by studies in controlled conditions that can provide insights into variation in life history and its effects on population dynamics. These studies suggest that life-history traits in Zamia can vary between individuals within populations, and also among populations and species. Within a population, plants can differ in traits like germination rate and seed and seedling size or the cost of reproduction. Populations in distinct habitats can differ in traits like early-stages survival rates, fecundity, and germination. Nevertheless , some life-history traits might not vary across populations in some species. Additionally , life history can vary drastically between species of Zamia from contrasting habitats. All this variation in life history can impact population dynamics, as shown by differing population growth rates in populations and species. Long-term monitoring http://dx.
Estimación de heredabilidad y correlaciones genéticas en caracteres morfológicos y fisiológicos p... more Estimación de heredabilidad y correlaciones genéticas en caracteres morfológicos y fisiológicos para una población de Zamia obliqua A.Br. (Zamiaceae: Cycadales) Estimation of heritability and genetic correlations in morphological and physiological traits for a population of Zamia obliqua A.Br. (Zamiaceae: Cycadales) Resumen La respuesta a la selección natural en caracteres cuantitativos en una población natural depende de la magnitud de variabilidad genética y las correlaciones genéticas en los rasgos, y estos parámetros genéticos pueden diferir entre categorías de rasgos. En este estudio se caracterizaron los patrones de varianza y covarianza fenotípica y se realizaron estimaciones de heredabilidad (h 2) y correlaciones genéticas de rasgos morfológicos y fisiológicos en una población de Zamia obliqua (Zamiaceae: Cycadales). Se probaron las hipótesis de que la varianza y la heredabilidad de rasgos morfológicos son mayores que las de rasgos fisiológicos, y que las correlaciones fenotípicas y genéticas son mayores dentro que entre las categorías de rasgos. Los valores de varianza fenotípica fueron mayores en los rasgos fisiológicos comparados con los caracteres morfológicos. Los estimativos de heredabilidad sugieren que los caracteres morfológicos presentan mayor varianza genética que los rasgos fisiológicos. Por otro lado, no se obtuvieron correlaciones genéticas significativas entre los rasgos. Sin embargo, las correlaciones fenotípicas muestran mayor correlación dentro de los caracteres morfológicos que dentro de los fisiológicos o entre rasgos morfológicos y fisiológicos. Estas estimaciones de parámetros genéticos permiten construir hipótesis sobre la evolución de caracteres fenotípicos en poblaciones naturales, y son aportes importantes al estudio de la ecología evolutiva de especies no modelo y sus poblaciones en hábitats naturales. Abstract The response to natural selection of quantitative traits in a natural population depends on the magnitude of genetic variability and genetic correlations between traits, and these genetic parameters can differ between trait categories. In this study we characterized the patterns of phenotypic variance and covariance and estimated heritability and genetic correlation of morphological and physiological traits in a population of Zamia oblique (Zamiaceae: Cycadales). We tested the hypothesis that variance and heritability values are higher for morphological than for physiological traits, and that phenotypic and genetic correlations are larger within than between trait categories. Phenotypic variance values were higher for physiological traits than for morphological characters. Heritability estimates suggested that morphological traits had a higher genetic variance than physiological traits. On the other hand, significant estimates of genetic correlations among traits were not obtained. Nevertheless, phenotypic correlations show a higher correlation within morphological traits than within physiological traits or among physiological and morphological traits. These kinds of estimates for genetic parameters can help generate hypotheses about the evolution of phenotypic traits in natural populations, and represent important contributions to the study of evolutionary ecology in non-model species and their populations in natural habitats.
The taxonomy of Zamia montana and Z. oligodonta, two poorly understood species occurring at high ... more The taxonomy of Zamia montana and Z. oligodonta, two poorly understood species occurring at high elevations in the Western Cordillera of Colombia, is discussed. Zamia oligodonta was recently synonymized under Z. montana, but information derived from recent field studies is provided showing the two species are quite distinct. A treatment of both species is presented , including discussion of the major morphological differences between them and also between other South American species with prominently-veined leaflets. The conservation status of both species is evaluated.
Rapid evolution may be common in human-dominated landscapes where environmental changes are sever... more Rapid evolution may be common in human-dominated landscapes where environmental changes are severe. We used phenotypic selection analyses and a markerbased method to estimate genetic variances and covariances to predict the potential response to selection in populations of a long-lived cycad recently exposed to drastic environmental changes. Patterns of selection in adult fecundity showed that different traits were under directional selection in subpopulations from native-undisturbed habitats and the novel degraded-forest habitat. Plants from a native-habitat subpopulation tend to maximize fitness through larger leaf area or smaller specific leaf area (SLA). In contrast, larger leaf production increased fitness in a degraded-habitat subpopulation, and canopy openness appears to be a major agent of selection for this trait. Leaf production and SLA showed significant additive genetic variance and no genetic trade-offs with examined traits, suggesting that these traits can respond to selection. Directional selection coefficients and heritability values were large, therefore significant phenotypic changes between subpopulations in few generations are possible. These results suggest that recent environmental change can result in strong directional selection in subpopulations of this cycad, and that these subpopulations have the potential to diverge at the genetic level in leaf traits after anthropogenic habitat degradation.
Habitat differences might promote adaptive differentiation among populations
that can be evidence... more Habitat differences might promote adaptive differentiation among populations
that can be evidenced by genotype-by-environment interactions (GxE). I examined
GxE in seed germination and seedling survival in demes of a rainforest cycad
across their native and degraded-forest habitats, and explored the role of maternal
effects and resource availability on the observed GxE. A reciprocal-transplant experiment showed a home-site advantage in terms of establishment of the demes.
Germination in a manipulative greenhouse experiment mirrored the patterns in
natural environments, with GxE in response to light and water availability. Overall
germination was lower in the degraded-forest habitat and under high-light and low-water conditions in the greenhouse. Several analysis suggested that maternal effects related to size on germination are weak, but maternal effects are suggested by better survival of larger seedlings in the degraded-forest habitat. With weak maternal effects, GxE in establishment of individuals suggest some adaptive differentiation across demes in this cycad, which could have implications for population persistence in its habitats.
Habitat degradation can result in drastic environmental changes potentially affecting the life-hi... more Habitat degradation can result in drastic environmental changes potentially affecting the life-history of populations and aspects of the reproductive biology and the genetic structure within and among populations. Here, we explore how life-history differences between subpopula-tions from contrasting habitats may affect mating availability , which in turn will indirectly affect the strength of spatial genetic structure within populations of a tropical rainforest cycad (Zamia fairchildiana). Subpopulations exposed to higher light availability in degraded-forest habitats had male individuals that grew faster, reproduced earlier, and invested more in reproduction than in native-forest habitat subpopulations. These differences in life history resulted in degraded-habitat subpopulations showing a higher proportion of reproductive adults and greater mate availability in a reproductive season. Subpopulations in the degraded habitat showed weaker SGS, i.e., a smaller slope in the linear regression of genetic relatedness on linear distance. Environmentally induced changes in life history and subsequent changes in the strength of the SGS after habitat degradation may have important consequences for population viability and should be of concern in conservation.
Like many species, the model plant Arabidopsis thaliana exhibits multiple different life historie... more Like many species, the model plant Arabidopsis thaliana exhibits multiple different life histories in natural environments. We grew mutants impaired in different signaling pathways in field experiments across the species’ native European range in order to dissect the mechanisms underlying this variation. Unexpectedly, mutational loss at loci implicated in the cold requirement for flowering had little effect on life history except in late-summer cohorts. A genetically informed photothermal model of progression toward flowering explained most of the observed variation and predicted an abrupt transition from autumn flowering to spring flowering in late-summer germinants. Environmental signals control the timing of this transition, creating a critical window of acute sensitivity to genetic and climatic change that may be common for seasonally regulated life history traits.
Reduced habitat quality after fragmentation can signiWcantly aVect population viability, but the ... more Reduced habitat quality after fragmentation can signiWcantly aVect population viability, but the eVects of diVering quality of the remaining habitat on population Wtness are rarely evaluated. Here, I compared fragmented populations of the cycad Zamia melanorrhachis from habitats with diVerent history and subject to contrasting levels of disturbance to explore potential demographic diVerences in populations across habitat patches that could diVer in habitat quality. Secondary-forest fragments had a lower canopy cover and soil moisture than remnant-forest fragments, which may represent a harsh environment for this cycad. A smaller average plant size and lower population density in the secondary-forest fragments support the hypothesis that these fragments may be of lower quality, e.g., if plants have reduced survival and/or fecundity in these habitats. However, variation in the stage-structure of populations (i.e., the relative proportions of non-reproductive and reproductive plants) was associated with the area of the forest fragments rather than the type of habitat (remnant versus secondary forest). These results suggest that diVerent demographic parameters may respond diVerently to habitat fragmentation, which may be explained if processes like adult survival and recruitment depend on diVerent characteristics of the habitat , e.g., average light/water availability versus suitable area for plant establishment. This study shows that forest fragments may diVer drastically in environmental conditions and can sustain populations that can vary in their demography. Understanding how forest fragments may represent diVerent habitat types is relevant for evaluating population viability in a heterogeneous landscape and for designing conservation programs that account for this heterogeneity.
Thesis Chapters by Cristina Lopez-Gallego
In addition to habitat loss and fragmentation, habitat degradation can have important consequence... more In addition to habitat loss and fragmentation, habitat degradation can have important consequences for biodiversity and population persistence, including effects on ecological and genetic processes beyond decreased demographic viability and the loss of genetic variation. Particularly interesting is the potential for evolutionary changes and adaptation to degraded habitats, that can affect population viability even in the short-term. Here, I explore how environmental changes after habitat degradation affect the evolutionary dynamics of populations of the rainforest cycad Zamia fairchildiana, specifically how habitat degradation affects gene dispersal, inbreeding, directional selection, and genotype-by-environment interactions, and the potential for genetic differentiation between populations. Colonies of Z. fairchildiana showed little genetic differentiation in neutral molecular markers across study sites, thus can be considered as subpopulations. Subpopulations in the disturbed habitat are experiencing different environmental conditions when compared to subpopulation in their native habitat. Disturbed-habitat subpopulations showed a faster life-history. This faster life history is associated with a weaker spatial genetic structure and higher levels of inbreeding in the disturbed-habitat subpopulations. In addition, higher light availability in the disturbed habitat seems to be a major agent of selection on traits like leaf production that have the potential to respond to selection in these subpopulations. Different traits were under selection in the native-habitat subpopulations, suggesting the potential for genetic differentiation between native and disturbed-habitat subpopulations. Genotype by environment interactions in seed germination and seedling survival, in response to light and water availability, further suggested that subpopulations can adaptively diverge between habitats, but the relative role of genetic and environmental factors, particularly maternal effects, on the magnitude and rate of genetic differentiation between subpopulations remains to be evaluated. These results suggest that habitat degradation can have important consequences for the evolutionary dynamics of populations of this cycad, not necessarily typical of habitat loss and fragmentation. This study identified factors and processes important for population persistence in degraded habitats, but population responses to habitat degradation are complex. Thus further studies and long-term experiments are required for better understanding the effects of habitat degradation on population viability.
Conference and EventsOrganization by Cristina Lopez-Gallego
La filosofía de la mente nació como una rama especializada de la filosofía en el siglo XX y ha te... more La filosofía de la mente nació como una rama especializada de la filosofía en el siglo XX y ha tenido un desarrollo considerable, al punto de ser una de las ramas más activas e innovadoras de la filosofía contemporánea. Además, dado que la mente es la característica fundamental de lo humano, muchos filósofos y teóricos se apoyan en la filosofía de la mente para realizar reflexiones que atañen otros temas como ética, la filosofía de la ciencia, la epistemología, y la estética, entre otros. Esta versión del Aula Abierta estudiará las posiciones y discusiones más importantes en filosofía de la mente. Las conferencias serán dictadas por profesores del Instituto de Filosofía, el departamento de psiquiatría, el departamento de psicología y el Instituto de Biología. Esto garantizará la interdisciplinariedad al abordar el tema.
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BOOKS by Cristina Lopez-Gallego
Papers by Cristina Lopez-Gallego
that can be evidenced by genotype-by-environment interactions (GxE). I examined
GxE in seed germination and seedling survival in demes of a rainforest cycad
across their native and degraded-forest habitats, and explored the role of maternal
effects and resource availability on the observed GxE. A reciprocal-transplant experiment showed a home-site advantage in terms of establishment of the demes.
Germination in a manipulative greenhouse experiment mirrored the patterns in
natural environments, with GxE in response to light and water availability. Overall
germination was lower in the degraded-forest habitat and under high-light and low-water conditions in the greenhouse. Several analysis suggested that maternal effects related to size on germination are weak, but maternal effects are suggested by better survival of larger seedlings in the degraded-forest habitat. With weak maternal effects, GxE in establishment of individuals suggest some adaptive differentiation across demes in this cycad, which could have implications for population persistence in its habitats.
Thesis Chapters by Cristina Lopez-Gallego
Conference and EventsOrganization by Cristina Lopez-Gallego
that can be evidenced by genotype-by-environment interactions (GxE). I examined
GxE in seed germination and seedling survival in demes of a rainforest cycad
across their native and degraded-forest habitats, and explored the role of maternal
effects and resource availability on the observed GxE. A reciprocal-transplant experiment showed a home-site advantage in terms of establishment of the demes.
Germination in a manipulative greenhouse experiment mirrored the patterns in
natural environments, with GxE in response to light and water availability. Overall
germination was lower in the degraded-forest habitat and under high-light and low-water conditions in the greenhouse. Several analysis suggested that maternal effects related to size on germination are weak, but maternal effects are suggested by better survival of larger seedlings in the degraded-forest habitat. With weak maternal effects, GxE in establishment of individuals suggest some adaptive differentiation across demes in this cycad, which could have implications for population persistence in its habitats.