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Intersexual signals that reveal developmental or mating status in females have evolved repeatedly in many animal lineages. Such signals have functions in sexual conflict over mating and can therefore influence sexually antagonistic coevolution. However, we know little about how female signal development modifies male mating harassment and thereby sexual conflict. Here, we combine phylogenetic comparative analyses of a color polymorphic damselfly genus (Ischnura) with behavioral experiments in one target species to investigate the evolutionary origin and current adaptive function of a developmental female color signal. Many Ischnura species have multiple female color morphs, which include a male-colored morph (male mimics) and one or two female morphs that differ markedly from males (heterochrome females). In Ischnura elegans , males and male-mimicking females express a blue abdominal patch throughout postemergence life. Using phenotypic manipulations, we show that the developmental expression of this signaling trait in heterochrome females reduces premating harassment prior to sexual maturity. Across species this signal evolved repeatedly, but in heterochrome females its origin is contingent on the signal expressed by co-occurring male-mimicking females. Our results suggest that the co-option of a male-like trait to a novel female antiharassment function plays a key role in sexual conflict driven by premating interactions. [ABSTRACT FROM AUTHOR]

Odonata (dragonflies and damselflies) present an unparalleled insect model to integrate evolutionary genomics with ecology for the study of insect evolution. Key features of Odonata include their ancient phylogenetic position, extensive phenotypic and ecological diversity, several unique evolutionary innovations, ease of study in the wild and usefulness as bioindicators for freshwater ecosystems worldwide. In this review, we synthesize studies on the evolution, ecology and physiology of odonates, highlighting those areas where the integration of ecology with genomics would yield significant insights into the evolutionary processes that would not be gained easily by working on other animal groups. We argue that the unique features of this group combined with their complex life cycle, flight behaviour, diversity in ecological niches and their sensitivity to anthropogenic change make odonates a promising and fruitful taxon for genomics focused research. Future areas of research that deserve increased attention are also briefly outlined. [ABSTRACT FROM AUTHOR]

The theory of island biogeography is most often studied in the context of oceanic islands where all island inhabitants are descendants from founding events involving migration from mainland source populations. Far fewer studies have considered predictions of island biogeography in the case of continental islands, where island formation typically splits continuous populations and thus vicariance also contributes to the diversity of island populations. We examined one such case on continental islands in southeastern Brazil, to determine how classic island biogeography predictions and past vicariance explain the population genetic diversity of Thoropa taophora, a frog endemic to the Atlantic Coastal Forest. We used nuclear microsatellite markers to examine the genetic diversity of coastal and island populations of this species. We found that island isolation has a role in shaping the genetic diversity of continental island species, with island populations being significantly less diverse than coastal populations. However, area of the island and distance from coast had no significant effect on genetic diversity. We also found no significant differences between migration among coastal populations and migration to and from islands. We discuss how vicariance and the effects of continued migration between coastal and island populations interact to shape evolutionary patterns on continental islands. [ABSTRACT FROM AUTHOR]

Microorganisms frequently colonize the nectar of angiosperm species. Though capable of altering a suite of traits important for pollinator attraction, few studies exist that test the degree to which they mediate pollinator foraging behavior. The objective of our study was to fill this gap by assessing the abundance and diversity of yeasts associated with the perennial larkspur Delphinium barbeyi (Ranunculaceae) and testing whether their presence affected components of pollinator foraging behavior. Yeasts frequently colonized D. barbeyi nectar, populating 54–77% of flowers examined depending on site. Though common, the yeast community was species-poor, represented by a single species, Metschnikowia reukaufii. Female-phase flowers of D. barbeyi were more likely to have higher densities of yeasts in comparison to male-phase flowers. Pollinators were likely vectors of yeasts, as virgin (unvisited) flowers rarely contained yeasts compared to flowers open to pollinator visitation, which were frequently colonized. Finally, pollinators responded positively to the presence of yeasts. Bombus foragers both visited and probed more flowers inoculated with yeasts in comparison to uninoculated controls. Taken together, our results suggest that variation in the occurrence and density of nectar-inhabiting yeasts have the potential to alter components of pollinator foraging behavior linked to pollen transfer and plant fitness. [ABSTRACT FROM AUTHOR]

Invasive species can dramatically impact natural populations, especially those living on islands. Though numerous examples illustrate the ecological impact of invasive predators, no study has examined the genetic consequences for native populations subject to invasion. Here we capitalize on a natural experiment in which a long-term study of the brown anole lizard (Anolis sagrei) was interrupted by rat invasion. An island population that was devastated by rats recovered numerically following rat extermination. However, population genetic analyses at six microsatellite loci suggested a possible loss of genetic diversity due to invasion when compared to an uninvaded island studied over the same time frame. Our results provide partial support for the hypothesis that invasive predators can impact the genetic diversity of resident island populations. [ABSTRACT FROM AUTHOR]

Comparative studies of codistributed taxa test the degree to which historical processes have shaped contemporary population structure. Discordant patterns of lineage divergence among taxa indicate that species differ in their response to common historical processes. The complex geologic landscape of the Isthmus of Central America provides an ideal setting to test the effects of vicariance and other biogeographic factors on population history. We compared divergence patterns between two codistributed Neotropical frogs ( Dendropsophus ebraccatus and Agalychnis callidryas) that exhibit colour pattern polymorphisms among populations, and found significant differences between them in phenotypic and genetic divergence among populations. Colour pattern in D. ebraccatus did not vary with genetic or geographic distance, while colour pattern co-varied with patterns of gene flow in A. callidryas. In addition, we detected significant species differences in the phylogenetic history of populations, gene flow among them, and the extent to which historical diversification and recent gene flow have been restricted by five biogeographic barriers in Costa Rica and Panama. We inferred that alternate microevolutionary processes explain the unique patterns of diversification in each taxon. Our study underscores how differences in selective regimes and species-typical ecological and life-history traits maintain spatial patterns of diversification. [ABSTRACT FROM AUTHOR]

Here we characterize nine microsatellite loci for Thoropa taophora collected from a coastal and an island population in southeastern Brazil. The number of alleles per locus ranged from three to 11 for the coastal population and from two to eight for the island population. Observed heterozygosities ranged from 0.308 to 0.778 for the coastal population and from zero to 0.737 for the island population. One locus did not conform to Hardy–Weinberg expectations on the coast, while two were in disequilibrium on the island. These markers are currently being used to examine genetic differentiation and patterns of dispersal in T. taophora. [ABSTRACT FROM AUTHOR]

Seed storage of species from the humid tropics is often problematic because of seed sensitivity to desiccation and low temperatures, conditions traditionally considered necessary for long-term seed storage.In this study, Brazil nut seeds from 10 families were stored for five-and-a-half months under moist conditions at warm ambient temperatures. A randomized complete block design was employed for analysis of seed moisture content and germination, with storage and family as the main treatment factors. Moist storage of Brazil nut seeds clearly improved germination and can greatly facilitate nursery management. Seeds that were stored and then had testas removed germinated more quickly (Day 14 versus Day 60), exhibited greater percentage germination (74.8 versus 53.5%), and a reduction in seed deterioration (25.2 versus46.5%). Storage also improved germination rate, and no seeds germinated prematurely while in storage. Moist storage improved germination of some families more than others such that stored seeds exhibited more uniform germination across all families. The delayed and prolongedgermination of nonstored seeds may be due to endogenous seed dormancy that appears to be favorable for increasing the effective storage period of Brazil nut. During storage, embryo maturation may have takenplace and/or a chemical inhibitor may have been leached from the embryos, resulting in improved Brazil nut germination. [ABSTRACT FROM AUTHOR]

We examined the accuracy of Smart Socks - a device that measures foot pressure during gait for detecting step-count across various walking speeds. Thirty-six participants (17 men; 19 women) wore Smart Socks (Sock), a pedometer (Pedometer), and a smartphone with a commercially available Phone Application (Phone) pedometer to measure step-count during 3-min of treadmill or over-ground walking at 1.3, 2.2, 3.0, 3.8, and 4.7 km/h. Steps were compared to a gold-standard tally-counter (Count), collected by independent assessors. All devices (Sock, Pedometer, and Phone) underestimated step-count when compared to Count at 1.3 km/h (p<0.05); however, Sock (27±18%) demonstrated a lower percent error compared to Phone (40±28%) and Pedometer (98±5%) (both p<0.01). At 2.2 km/h, Sock was not different compared to Count (Sock: 213±39; Count: 229±24 steps, p=0.25); however, both Phone (271±55 steps) and Pedometer (169±166 steps) were different compared to Count (p<0.05). At 3.0 km/h, both Sock (258±30 steps) and Pedometer (254±45 steps) were similar to Count (267±22 steps) (p>0.05); however, Phone (291±28 steps) overestimated step-count (p<0.01). All devices (Sock, Pedometer, and Phone) were similar to Count at 3.8, and 4.7 km/h (p>0.05). These findings demonstrate that Smart Socks are more accurate than pedometers used in the present study for detecting step-count during treadmill or over-ground ambulation at slower walking speeds., Competing Interests: The authors declare no conflict of interest., (© Georg Thieme Verlag KG Stuttgart · New York.)

We analyze how spatial heterogeneity in host density affects the advance of vector-borne disease. Infection requires vector infestation. The vector spreads only between hosts occupying the same neighborhood, and the number of hosts varies randomly among neighborhoods. Simulation of a spatially detailed model shows that increasing heterogeneity in host abundance reduces pathogen prevalence. Clumping of hosts can limit the advance of the vector, which inhibits the spread of infection indirectly. Clumping can also increase the chance that the pathogen and vector become physically separated during the initial phase of the epidemic process. The latter limitation on the pathogen's spread, in our simulations, is restricted to small interaction neighborhoods. A mean-field model, which does not maintain spatial correlations between sites, approximates simulation results when hosts are arrayed uniformly, but overestimates infection prevalence when hosts are aggregated. A pair approximation, which includes some of the simulation model's spatial correlations, better describes the vector infestation frequencies across host spatial dispersions., (Copyright 2001 Academic Press.)

Spatially explicit epidemic models explore population-level consequences of interactions between neighboring infectious and susceptible individuals. Most such models equate local and global host density, so that each individual interacts with the same number of neighbors. But many natural populations exhibit heterogeneity in local abundance. Therefore, we let host dispersion vary from uniform to clumped in a spatial epidemic with recovery. We analytically approximated the epidemic with a branching process to show how the probability of pathogen extinction could depend on the degree of host clumping. We then simulated the detailed model across a range of parameter combinations. Both approaches to the problem indicate that host spatial aggregation strongly increases the chance of pathogen extinction.

In the course of performing a linkage analysis on rats bred from inbred doubly heterozygous parents, we observed the following counterintuitive finding: the lod scores more strongly supported the hypothesis that all the recombinations occurred in one sex (without specifying which sex), rather than that some recombinations occurred in each sex. In this brief paper we explain how this apparent anomaly can arise. We point out that very different values of the recombination fraction vector theta = (theta Male, theta Female) can give rise to likelihoods that do not differ by much. We suggest that caution be exercised when investigators interpret results of linkage analyses in which estimates of theta Male and theta Female differ widely.

Seedlings of two fast- and two slow-growing families of slash pine, Pinus elliottii Englm. var. elliottii, were grown in a greenhouse for one growing season in one of 10 nitrogen (N) regimes. Increasing the N concentration in the nutrient solution resulted in both increased growth rates during the exponential growth phase and extended duration of the growing season. The two components of total height, free growth (epicotyl length to the first bud) and summer growth (height growth after the first bud), both increased significantly with increasing N concentrations up to 40-60 mg l(-1) but decreased at N concentrations above 180 mg l(-1). Compared to seedlings grown in the presence of an optimum N concentration, seedlings grown in the presence of trace amounts of N were smaller and had less summer growth as a percentage of total growth, earlier cessation of height growth, fewer flushes, lower shoot/root ratio, higher root fibrosity, and lower N concentrations in all seedling tissues. Compared to slow-growing families, fast-growing families had more summer height growth, more flushes and later growth cessation, higher shoot/root ratios and higher root fibrosity at all N concentrations. In the presence of an optimum or higher concentration of N, the fast-growing families also had higher needle and total N concentrations than the slow-growing families. Strong family by N-treatment interactions occurred for height, phenology and biomass traits because of the extra responsiveness of one family to increasing N concentration. Several seedling traits were identified that appear promising for predicting field performance in slash pine. The results indicated that the nutrient environment greatly influences genetic expression (e.g., family patterns of summer growth were most closely related to field rankings for seedlings in the trace-N treatment).

Bud dormancy of root wrenched and unwrenched slash pine (Pinus elliottii Engelm.) seedlings growing in a forest nursery was measured on five lifting dates. Determination of bud dormancy was based on days to budbreak (DBB) under optimal growing conditions, mitotic activity in the apical meristem, chilling hours accumulated, and bud morphology. Based on DBB, seedlings were most dormant at Lift 2 on November 24 after exposure to 189 hours below 10 degrees C and 93 hours below 6.7 degrees C. Mitotic activity in the apical meristem was at its lowest 23 days later at Lift 3, possibly indicating the period when seedlings are most resistant to transplanting stresses. Multiple wrenching resulted in a slight shift in the dormancy cycle as wrenched seedlings set bud sooner in the nursery and broke bud sooner at the planting site in the spring than control seedlings. This implies that wrenched seedlings can be successfully lifted from the nursery earlier and will initiate spring shoot growth earlier than control seedlings.

Modesty has been defined as decorum in relation to physical nakedness, and sexual and eliminative behavior (Newson and Newson 1968). The connection between nakedness, sexuality, and modesty with respect to family members dates back millennia. Leviticus prohibited incest with the phrase, "Thou shalt not uncover the nakedness of ..." and then specified a lengthy list of forbidden relatives. We will review contemporary theories and research projects concerning modesty and then discuss the results of a study we designed in order to investigate age trends in the development of modesty.