Sexual dichromatism and sexual dimorphism of body size are reasonably well studied in butterflies... more Sexual dichromatism and sexual dimorphism of body size are reasonably well studied in butterflies. Sexual size dimorphism of color pattern elements, however, is much less explored. The object of this study is Heliconius, a genus of butterflies well known for the coevolution between mate color preferences and mimicry. Given the sexual role of wing coloration, we investigated the existence of sexual size dimorphism in the wing color elements of a mimetic pair-Heliconius erato phyllis Fabricius and Heliconius besckei Ménétriés-and analyzed the allometric patterns of these traits. Correlation between size of elements in the dorsal and ventral wing surfaces were also estimated. In both species, three out of four elements were larger in males, but the non-dimorphic element was not the same. With regard to the allometric patterns, our most important finding was that smaller males of one species have proportionally larger yellow bars. This is the first study specifically concerning quantitative sexual dimorphism in the coloration of this well-known genus of butterflies and it opens new prospects to investigate sex-related natural selection and sexual selection of color pattern elements.
A total of 4,724 White and 1,013 Black healthy newborn children were investigated. No significant... more A total of 4,724 White and 1,013 Black healthy newborn children were investigated. No significant race differences were observed among those with apparently the same socioeconomic level. In two thirds of the comparisons made the values found in Porto Alegre proved to be higher than those encountered in other Brazilian populations. Multiple regression analysis performed in a subsample indicated an effect in the two racial groups of mother’s height and weight in the variable under investigation. Parity, age of father, and parents’ marital distance may also be important but in relation to them significant effects were observed among the Whites only
Positive allometric patterns observed for intersexual signalling characters are related to direct... more Positive allometric patterns observed for intersexual signalling characters are related to directional sexual selection, and supported by theoretical and empirical data. Recent models have shown that positive allometry may not hold as a rule if the influence of natural selection is added to the model. Here we tested these models applying traditional morphometrical techniques for the analysis of chelicerae sexual dimorphism and allometric patterns within the genus Paratrechalea: Paratrechalea azul, Paratrechalea galianoae and Paratrechalea ornata. Spider chelicerae are basically used for prey capture, but males of Paratrechalea also use the chelicerae to offer a nuptial gift during courtship, also presenting a clear size and colour sexual dimorphism supporting a possible role as a signal. Chelicerae size was male biased for all the variables studied and showed an isometric pattern, while females showed a higher variation. Our findings are in accordance with models of viability-related function for prey capture, questioning some statements proposed by the positive allometry model.
The breeding structure of both colony and population of social insects can be examined by genetic... more The breeding structure of both colony and population of social insects can be examined by genetic analysis. Colonies of the leaf-cutting ants Acromyrmex heyeri and A. striatus (Myrmicinae, Attini) were thus analyzed for isoenzyme systems MDH, a-GPDH, and AMY to describe genotype variability and social structure. A total of five loci were investigated (three for amylase and one for each other system). Ninety-seven colonies of A. heyeri and 103 of A. striatus were sampled in different localities in Southern Brazil (State of Rio Grande do Sul). The genotypes found show the occurrence of monogyny and polygyny associated or not with polyandry, which indicates that the social organization is colony-specific. The polygyny and polyandry observed are likely to be responsible for the great genotypic diversity of the colonies. The average inbreeding coefficient per colony was higher in A. striatus than in A. heyeri, which may reflect the different patterns of production of sexual individuals a...
www.sbg.org.br Phylogenetic relationships and the evolution of mimicry in the Chauliognathus yell... more www.sbg.org.br Phylogenetic relationships and the evolution of mimicry in the Chauliognathus yellow-black species complex (Coleoptera: Cantharidae) inferred from mitochondrial COI sequences
Principia: an international journal of epistemology, 2015
http://dx.doi.org/10.5007/1808-1711.2015v19n2p263The Modern Evolutionary Synthesis relegated the ... more http://dx.doi.org/10.5007/1808-1711.2015v19n2p263The Modern Evolutionary Synthesis relegated the ontogenetic development to a “black box”. In this article, we argue that the absence of ontogenetic development in the Evolutionary Synthesis was due its strong foundation in transmission genetics. We discuss three research strategies of transmission genetics that created an incompatibility with the ontogenetic development: (i) particulate inheritance model; (ii) population as locus for genetics research; (iii) and experimental tools that have been applied to remove “non-heritable fluctuations” from ontogenetic and environmental effects. These practices have contributed to the strength of the genetic inheritance, but also excluded the ontogenetic development from the explanation of heredity and evolution. This distinction has been perpetuated in the Evolutionary Synthesis.
The goal of this paper was to test the presence of mimicry in Asclepias curassavica L., Epidendru... more The goal of this paper was to test the presence of mimicry in Asclepias curassavica L., Epidendrum fulgens Brong., and Lantana camara L. The study was carried out at the Parque Estadual de Itapeva, RS, southern Brazil, from 2004 to 2006. Flowering period of each of the three species was followed up; focal observations of butterflies visiting flowers, from fixed point and during random walks were carried out. We also estimated the frequency of pollinaria removal in the orchid, as well as its mode of reproduction. All these variables were important for testing the mimicry hypothesis. Despite some temporal coincidences in the flowering period of two plants in the system, there was no statistical association among the three plants as to flowering period. Twenty-nine species of butterflies, as potential pollinators, were recorded, particularly Agraulis vanillae maculosa, Dryas iulia alcionea, Urbanus simplicius, Tegosa claudina, and Heliconius erato phyllis, which were the more frequent ...
Eurema elathea adults were censused weekly (1992-1994) in six night-roosts around a forest fragme... more Eurema elathea adults were censused weekly (1992-1994) in six night-roosts around a forest fragment on a farm, and in two roosts in the urban area of Uberlândia, Minas Gerais, Brazil. Males were grouped in six phenotypic classes. These were based on a range between having a conspicuous wide black bar at the dorsal forewing inner margin (wet season dark morphs) and the absence of that bar (dry season light morphs). The body mass and wing area of co-occurring morphs were compared: differents morphs showed similar means. The abundance of butterflies and morph frequencies varied in close relation to humidity (rainfall). Individuals were infrequent and monomorphically dark in the wet season while light morphs predominated in dry periods when population peaked. A lower fraction of recaptured individuals and higher recruitment were recorded compared to other night-roosting butterflies. Dispersal potential was similar between the sexes and varied seasonally with a more sedentary population ...
Sexual dichromatism and sexual dimorphism of body size are reasonably well studied in butterflies... more Sexual dichromatism and sexual dimorphism of body size are reasonably well studied in butterflies. Sexual size dimorphism of color pattern elements, however, is much less explored. The object of this study is Heliconius, a genus of butterflies well known for the coevolution between mate color preferences and mimicry. Given the sexual role of wing coloration, we investigated the existence of sexual size dimorphism in the wing color elements of a mimetic pair-Heliconius erato phyllis Fabricius and Heliconius besckei Ménétriés-and analyzed the allometric patterns of these traits. Correlation between size of elements in the dorsal and ventral wing surfaces were also estimated. In both species, three out of four elements were larger in males, but the non-dimorphic element was not the same. With regard to the allometric patterns, our most important finding was that smaller males of one species have proportionally larger yellow bars. This is the first study specifically concerning quantitative sexual dimorphism in the coloration of this well-known genus of butterflies and it opens new prospects to investigate sex-related natural selection and sexual selection of color pattern elements.
Male delivering of a prey packed in silk as a nuptial gift is rare in spiders and restricted unti... more Male delivering of a prey packed in silk as a nuptial gift is rare in spiders and restricted until now to Pisauridae. Here, we describe this behavioral pattern found in two Trechaleidae species, Paratrechalea azul Carico 2005, and Paratrechalea ornata (Mello-Leitão 1943), mainly based on field observations. We observed the following steps of sexual behavior: sperm induction, nuptial gift construction, mate searching, pre-copulatory courtship, copulation, and copulatory ending. In this group, a nuptial gift consists of a prey wrapped in silk, which appears as a white rounded shape. The male carries his nuptial gift in his chelicerae while searching for a female. When he finds a female, he shows a stereotyped courting behavior consisting of a hyperflexed posture that is also assumed by the receptive female while they face each other. The copulatory position and pattern is similar to that found in other Lycosoidea: the male mounts the female and makes a total of four palpal insertions while alternating sides. However, after each palpal insertion the male dismounts and returns to a frontal position while biting the gift. Copulatory courtship is evidenced by palpal and leg movements. The copulation ends by female initiative and she almost always retains the nuptial gift. No case of pre-copulatory or post-copulatory cannibalism has been recorded. Descriptions of nuptial gift construction by males and copulation in these species, as well as hypotheses about the origin of nuptial gift construction among spiders, are presented. These descriptions are the first records of such nuptial gift offering for Neotropical spiders and for non-Pisauridae species as well.
Plants bearing extrafloral nectaries can attract wasps, bugs, and mainly ants. Ants
can defend p... more Plants bearing extrafloral nectaries can attract wasps, bugs, and mainly ants. Ants
can defend plants against herbivores by treating the plant as an extension of their
own territory. We evaluated the efficiency of resting sites built by Dryas iulia
alcionea larvae as protection against ant predation on their host plant Passiflora
suberosa. The results showed that ants on P. suberosa have significant influence
on the survival of D. iulia caterpillars. The use and construction of resting sites
was recorded through the fourth larval stadium. A strong inverse relationship
between the number of resting sites constructed per larva and the developmental
stage of the larvae was observed. Additional results suggest that the efficacy of
resting sites against cursorial predators decreases with larval development. The
behaviour of constructing resting sites probably evolved by natural selection. It is
likely that this behaviour was important for the ancestral lineage that gave origin
to Heliconiinae genera Dryas, Dryadula and Phylaethria.
Sexual dichromatism and sexual dimorphism of body size are reasonably well studied in butterflies... more Sexual dichromatism and sexual dimorphism of body size are reasonably well studied in butterflies. Sexual size dimorphism of color pattern elements, however, is much less explored. The object of this study is Heliconius, a genus of butterflies well known for the coevolution between mate color preferences and mimicry. Given the sexual role of wing coloration, we investigated the existence of sexual size dimorphism in the wing color elements of a mimetic pair-Heliconius erato phyllis Fabricius and Heliconius besckei Ménétriés-and analyzed the allometric patterns of these traits. Correlation between size of elements in the dorsal and ventral wing surfaces were also estimated. In both species, three out of four elements were larger in males, but the non-dimorphic element was not the same. With regard to the allometric patterns, our most important finding was that smaller males of one species have proportionally larger yellow bars. This is the first study specifically concerning quantitative sexual dimorphism in the coloration of this well-known genus of butterflies and it opens new prospects to investigate sex-related natural selection and sexual selection of color pattern elements.
A total of 4,724 White and 1,013 Black healthy newborn children were investigated. No significant... more A total of 4,724 White and 1,013 Black healthy newborn children were investigated. No significant race differences were observed among those with apparently the same socioeconomic level. In two thirds of the comparisons made the values found in Porto Alegre proved to be higher than those encountered in other Brazilian populations. Multiple regression analysis performed in a subsample indicated an effect in the two racial groups of mother’s height and weight in the variable under investigation. Parity, age of father, and parents’ marital distance may also be important but in relation to them significant effects were observed among the Whites only
Positive allometric patterns observed for intersexual signalling characters are related to direct... more Positive allometric patterns observed for intersexual signalling characters are related to directional sexual selection, and supported by theoretical and empirical data. Recent models have shown that positive allometry may not hold as a rule if the influence of natural selection is added to the model. Here we tested these models applying traditional morphometrical techniques for the analysis of chelicerae sexual dimorphism and allometric patterns within the genus Paratrechalea: Paratrechalea azul, Paratrechalea galianoae and Paratrechalea ornata. Spider chelicerae are basically used for prey capture, but males of Paratrechalea also use the chelicerae to offer a nuptial gift during courtship, also presenting a clear size and colour sexual dimorphism supporting a possible role as a signal. Chelicerae size was male biased for all the variables studied and showed an isometric pattern, while females showed a higher variation. Our findings are in accordance with models of viability-related function for prey capture, questioning some statements proposed by the positive allometry model.
The breeding structure of both colony and population of social insects can be examined by genetic... more The breeding structure of both colony and population of social insects can be examined by genetic analysis. Colonies of the leaf-cutting ants Acromyrmex heyeri and A. striatus (Myrmicinae, Attini) were thus analyzed for isoenzyme systems MDH, a-GPDH, and AMY to describe genotype variability and social structure. A total of five loci were investigated (three for amylase and one for each other system). Ninety-seven colonies of A. heyeri and 103 of A. striatus were sampled in different localities in Southern Brazil (State of Rio Grande do Sul). The genotypes found show the occurrence of monogyny and polygyny associated or not with polyandry, which indicates that the social organization is colony-specific. The polygyny and polyandry observed are likely to be responsible for the great genotypic diversity of the colonies. The average inbreeding coefficient per colony was higher in A. striatus than in A. heyeri, which may reflect the different patterns of production of sexual individuals a...
www.sbg.org.br Phylogenetic relationships and the evolution of mimicry in the Chauliognathus yell... more www.sbg.org.br Phylogenetic relationships and the evolution of mimicry in the Chauliognathus yellow-black species complex (Coleoptera: Cantharidae) inferred from mitochondrial COI sequences
Principia: an international journal of epistemology, 2015
http://dx.doi.org/10.5007/1808-1711.2015v19n2p263The Modern Evolutionary Synthesis relegated the ... more http://dx.doi.org/10.5007/1808-1711.2015v19n2p263The Modern Evolutionary Synthesis relegated the ontogenetic development to a “black box”. In this article, we argue that the absence of ontogenetic development in the Evolutionary Synthesis was due its strong foundation in transmission genetics. We discuss three research strategies of transmission genetics that created an incompatibility with the ontogenetic development: (i) particulate inheritance model; (ii) population as locus for genetics research; (iii) and experimental tools that have been applied to remove “non-heritable fluctuations” from ontogenetic and environmental effects. These practices have contributed to the strength of the genetic inheritance, but also excluded the ontogenetic development from the explanation of heredity and evolution. This distinction has been perpetuated in the Evolutionary Synthesis.
The goal of this paper was to test the presence of mimicry in Asclepias curassavica L., Epidendru... more The goal of this paper was to test the presence of mimicry in Asclepias curassavica L., Epidendrum fulgens Brong., and Lantana camara L. The study was carried out at the Parque Estadual de Itapeva, RS, southern Brazil, from 2004 to 2006. Flowering period of each of the three species was followed up; focal observations of butterflies visiting flowers, from fixed point and during random walks were carried out. We also estimated the frequency of pollinaria removal in the orchid, as well as its mode of reproduction. All these variables were important for testing the mimicry hypothesis. Despite some temporal coincidences in the flowering period of two plants in the system, there was no statistical association among the three plants as to flowering period. Twenty-nine species of butterflies, as potential pollinators, were recorded, particularly Agraulis vanillae maculosa, Dryas iulia alcionea, Urbanus simplicius, Tegosa claudina, and Heliconius erato phyllis, which were the more frequent ...
Eurema elathea adults were censused weekly (1992-1994) in six night-roosts around a forest fragme... more Eurema elathea adults were censused weekly (1992-1994) in six night-roosts around a forest fragment on a farm, and in two roosts in the urban area of Uberlândia, Minas Gerais, Brazil. Males were grouped in six phenotypic classes. These were based on a range between having a conspicuous wide black bar at the dorsal forewing inner margin (wet season dark morphs) and the absence of that bar (dry season light morphs). The body mass and wing area of co-occurring morphs were compared: differents morphs showed similar means. The abundance of butterflies and morph frequencies varied in close relation to humidity (rainfall). Individuals were infrequent and monomorphically dark in the wet season while light morphs predominated in dry periods when population peaked. A lower fraction of recaptured individuals and higher recruitment were recorded compared to other night-roosting butterflies. Dispersal potential was similar between the sexes and varied seasonally with a more sedentary population ...
Sexual dichromatism and sexual dimorphism of body size are reasonably well studied in butterflies... more Sexual dichromatism and sexual dimorphism of body size are reasonably well studied in butterflies. Sexual size dimorphism of color pattern elements, however, is much less explored. The object of this study is Heliconius, a genus of butterflies well known for the coevolution between mate color preferences and mimicry. Given the sexual role of wing coloration, we investigated the existence of sexual size dimorphism in the wing color elements of a mimetic pair-Heliconius erato phyllis Fabricius and Heliconius besckei Ménétriés-and analyzed the allometric patterns of these traits. Correlation between size of elements in the dorsal and ventral wing surfaces were also estimated. In both species, three out of four elements were larger in males, but the non-dimorphic element was not the same. With regard to the allometric patterns, our most important finding was that smaller males of one species have proportionally larger yellow bars. This is the first study specifically concerning quantitative sexual dimorphism in the coloration of this well-known genus of butterflies and it opens new prospects to investigate sex-related natural selection and sexual selection of color pattern elements.
Male delivering of a prey packed in silk as a nuptial gift is rare in spiders and restricted unti... more Male delivering of a prey packed in silk as a nuptial gift is rare in spiders and restricted until now to Pisauridae. Here, we describe this behavioral pattern found in two Trechaleidae species, Paratrechalea azul Carico 2005, and Paratrechalea ornata (Mello-Leitão 1943), mainly based on field observations. We observed the following steps of sexual behavior: sperm induction, nuptial gift construction, mate searching, pre-copulatory courtship, copulation, and copulatory ending. In this group, a nuptial gift consists of a prey wrapped in silk, which appears as a white rounded shape. The male carries his nuptial gift in his chelicerae while searching for a female. When he finds a female, he shows a stereotyped courting behavior consisting of a hyperflexed posture that is also assumed by the receptive female while they face each other. The copulatory position and pattern is similar to that found in other Lycosoidea: the male mounts the female and makes a total of four palpal insertions while alternating sides. However, after each palpal insertion the male dismounts and returns to a frontal position while biting the gift. Copulatory courtship is evidenced by palpal and leg movements. The copulation ends by female initiative and she almost always retains the nuptial gift. No case of pre-copulatory or post-copulatory cannibalism has been recorded. Descriptions of nuptial gift construction by males and copulation in these species, as well as hypotheses about the origin of nuptial gift construction among spiders, are presented. These descriptions are the first records of such nuptial gift offering for Neotropical spiders and for non-Pisauridae species as well.
Plants bearing extrafloral nectaries can attract wasps, bugs, and mainly ants. Ants
can defend p... more Plants bearing extrafloral nectaries can attract wasps, bugs, and mainly ants. Ants
can defend plants against herbivores by treating the plant as an extension of their
own territory. We evaluated the efficiency of resting sites built by Dryas iulia
alcionea larvae as protection against ant predation on their host plant Passiflora
suberosa. The results showed that ants on P. suberosa have significant influence
on the survival of D. iulia caterpillars. The use and construction of resting sites
was recorded through the fourth larval stadium. A strong inverse relationship
between the number of resting sites constructed per larva and the developmental
stage of the larvae was observed. Additional results suggest that the efficacy of
resting sites against cursorial predators decreases with larval development. The
behaviour of constructing resting sites probably evolved by natural selection. It is
likely that this behaviour was important for the ancestral lineage that gave origin
to Heliconiinae genera Dryas, Dryadula and Phylaethria.
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can defend plants against herbivores by treating the plant as an extension of their
own territory. We evaluated the efficiency of resting sites built by Dryas iulia
alcionea larvae as protection against ant predation on their host plant Passiflora
suberosa. The results showed that ants on P. suberosa have significant influence
on the survival of D. iulia caterpillars. The use and construction of resting sites
was recorded through the fourth larval stadium. A strong inverse relationship
between the number of resting sites constructed per larva and the developmental
stage of the larvae was observed. Additional results suggest that the efficacy of
resting sites against cursorial predators decreases with larval development. The
behaviour of constructing resting sites probably evolved by natural selection. It is
likely that this behaviour was important for the ancestral lineage that gave origin
to Heliconiinae genera Dryas, Dryadula and Phylaethria.
can defend plants against herbivores by treating the plant as an extension of their
own territory. We evaluated the efficiency of resting sites built by Dryas iulia
alcionea larvae as protection against ant predation on their host plant Passiflora
suberosa. The results showed that ants on P. suberosa have significant influence
on the survival of D. iulia caterpillars. The use and construction of resting sites
was recorded through the fourth larval stadium. A strong inverse relationship
between the number of resting sites constructed per larva and the developmental
stage of the larvae was observed. Additional results suggest that the efficacy of
resting sites against cursorial predators decreases with larval development. The
behaviour of constructing resting sites probably evolved by natural selection. It is
likely that this behaviour was important for the ancestral lineage that gave origin
to Heliconiinae genera Dryas, Dryadula and Phylaethria.