Higher-level phylogeny of trogoniformes

Phylogenetic relationships between Trogoniformes and several other putative closely related groups of birds, based on complete cytochrome b and nearly complete 12S ribosomal RNA sequences, were studied. The taxa included trogons, owls, cuckoos, parrots, nightjars, hummingbirds, kingfishers, motmots, rollers, mousebirds, and woodpeckers. The group most commonly suggested as the nearest relative to trogons had been the coraciiforms (kingfishers, rollers, and allies) but this hypothesis was not supported. It appeared that Trogons are more closely related to mousebirds, parrots, and perhaps cuckoos than to coraciiforms. Conflicting results, however, prevented precise determination of higher-level phylogenetic affinities of trogons. A saturation analysis showed evident saturation in cytochrome b third positions and 12S loops. After saturated partitions were removed, the phylogeny supported the mousebirds (Coliiformes) as the sister taxon to trogons. Phylogenetic inconsistencies appeared to be attributable to an imbalance between the lengths of terminal and internodal branches. Apparently, the limited number of characters supporting internodal branches exemplifies a relatively rapid cladogenesis at an early period in the evolutionary history of these birds.     

Chimpanzee facial symmetry: a biometric measure of chimpanzee health

This paper reports a study of fitness indicator theory in chimpanzees. First, it establishes a theoretical perspective for the study of fitness indicator theory and the relationships among indicators of fitness in humans and other animals. Second, it describes a methodology for assessing facial fluctuating asymmetry (FA) in a sample (N = 21) of zoo chimpanzees (Pan troglodytes). Third, associations among chimpanzee facial FA and health are described. FA was positively associated with negative health symptoms, and negatively associated with general health. Results are discussed under the framework of good genes theory.     

Dynamical Systems Approach to Higher-level Heritability

To explain higher-level heritability, we propose a dynamical systems approach, based on simulations of the high-dimensional replicator equation with mutation dynamics. We assume that all variants are generated from within the groups of variants through mutations. Simulating the equation with a random interaction matrix and possible variants, we report that this system tends to have many attractors, of fixed point, chaotic and quasiperiodic type. In a chaotic attractor, special gene-like variants appear to control the heritability ofthe system, in the sense that removal of the variants would easily enable the system to depart from the attractor. Those variants do not predominate in thepopulation size, but have the lowest net reproduction and mutation rates on average. Because their rate of growth is small, they are named neutral phenotypes. Additionally, combinatorial effects of these neutral variants to the entire system are reported.     

The face of another: anonymity and facial symmetry influence cooperation in social dilemmas

In the present paper, we study how the morphological features related to developmental physiology of other participants influence the decision to cooperate in a social dilemma. To that end, we let a large sample of men play a prisoner's dilemma game, both anonymously and against a series of counterparts whose photographs were shown. We focus on three characteristics already linked to cooperative behavior and with described effects on the adult facial shape: facial fluctuating asymmetry, a frequently employed but debated proxy for developmental instability; the degree of facial dimorphism, related to levels of testosterone during puberty; and the second to fourth digit ratio, related to relative prenatal testosterone exposure. We find significantly higher cooperation rates in anonymous interactions than in the non-anonymous round. We also find that individuals are more likely to cooperate with more asymmetric counterparts, and that more asymmetric participants were less likely to believe that their counterpart would cooperate. Variables related to exposure to testosterone during development do not display any effect. We conclude by discussing how out-of-the-game rewards can explain our results.     

Higher-level crustacean phylogeny: Consensus and conflicting hypotheses

This paper presents an overview of current hypotheses of higher-level crustacean phylogeny in order to assist and help focus further research. It concentrates on hypotheses proposed or debated in the recent literature based on morphological, molecular and combined evidence phylogenetic analyses. It can be concluded that crustacean phylogeny remains essentially unresolved. Conflict is rife, irrespective of whether one compares different morphological studies, molecular studies, or both. Using the number of recently proposed alternative sister group hypotheses for each of the major tetraconatan taxa as a rough estimate of phylogenetic uncertainty, it can be concluded that the phylogenetic position of Malacostraca remains the most problematic, closely followed by Branchiopoda, Cephalocarida, Remipedia, Ostracoda, Branchiura, Copepoda and Hexapoda. Future progress will depend upon a broader taxon sampling in molecular analyses, and the further exploration of new molecular phylogenetic markers. However, the need for continued revision and expansion of morphological datasets remains undiminished given the conspicuous lack of agreement between molecules and morphology for positioning several taxa. In view of the unparalleled morphological diversity of Crustacea, and the likely nesting of Hexapoda somewhere within Crustacea, working out a detailed phylogeny of Tetraconata is a crucial step towards understanding arthropod body plan evolution.     

Localization of sensory mechanisms utilized by coral planulae to detect settlement cues

Coral planulae are induced to settle and metamorphose by contact with either crustose coralline algae or marine bacterial biofilms. Larvae of two coral species, Pocillopora damicornis and Montipora capitata, which respond to different metamorphic cues, were utilized to investigate the sensory mechanisms used to detect metamorphic cues. Because the aboral pole of the coral planula is the point of attachment to the substratum, we predicted that it is also the point of detection for cues. To determine where sensory cells for cues are localized along the body, individual larvae were transversely cut into oral and aboral portions at various levels along the oral–aboral axis, and exposed to settlement‐inducing substrata. Aboral ends of M. capitata metamorphosed, while oral ends continued to swim. However, in larvae of P. damicornis, ¾ oral ends (i.e., lacking the aboral pole) were also able to metamorphose, indicating that the cells that detect cues may be distributed along the sides of the body. These cells do not correspond to FMRFamide‐immunoreactive cells that are present throughout the body. Cesium ions induced both aboral and oral ends of larvae of both species to settle, suggesting that oral ends have not lost their capacity to metamorphose, despite lacking sensory cells to detect natural cues. To determine whether sensory cells in larvae of P. damicornis are restricted to one side of the body, swimming behavior over substrata was observed in larvae labeled with diI, a red fluorescent lipophilic membrane stain. The larvae were found to rotate around the oral–aboral axis, with their surface against the substratum, not favoring a particular side for detecting cues. While clarifying the regions of the larval body important for settlement and metamorphosis in coral planulae, we conclude that significant differences between coral species may be due to differences in the distribution of sensory structures in relation to different planular sizes.     

Higher-level systematics of Acanthaceae determined by chloroplast DNA sequences

Parsimony analyses of ndhF chloroplast gene sequences were undertaken for 15 species of Acanthaceae and nine representative outgroup species. In addition, parsimony analyses of rbcL sequences were undertaken for 12 species of Acanthaceae and the same nine outgroup species as for ndhF. The results indicate that ndhF provides more informative characters and greater systematic resolution at this hierarchical level than rbcL. The ndhF analyses demonstrate that Elytraria and Thunbergia are successive sister taxa to all Acanthaceae taxa that have retinacula and explosive fruits. These data also demonstrate that taxa with both retinacula and explosive fruits can be subdivided further into two monophyletic groups that correspond to taxa with and without cystoliths. Within the group with cystoliths three putatively monophyletic groups correspond to taxa possessing quincuncial, left contort, and ascending-cochlear corolla aestivation patterns. The results of the rbcL analysis provide less systematic resolution than ndhF but do contain several congruent arrangements of taxa within Acanthaceae.     

蜻蜓目高级阶元系统发育关系研究进展

综述了对蜻蜓目系统发育的研究。对一些规模较大较全面的研究结果做了描述,并对其进行比较;对最近的基于分子的和基于形态的研究的共同点做了总结,其共同支持的观点包括:束翅亚目处于分支的基部为一并系类群,差翅亚目与间翅亚目关系较近。     

A genome-screen experiment to detect quantitative trait loci affecting resistance to facial eczema disease in sheep

Facial eczema (FE) is a secondary photosensitization disease arising from liver cirrhosis caused by the mycotoxin sporidesmin. The disease affects sheep, cattle, deer and goats, and costs the New Zealand sheep industry alone an estimated NZ$63M annually. A long-term sustainable solution to this century-old FE problem is to breed for disease-resistant animals by marker-assisted selection. As a step towards finding a diagnostic DNA test for FE sensitivity, we have conducted a genome-scan experiment to screen for quantitative trait loci (QTL) affecting this trait in Romney sheep. Four F₁ sires, obtained from reciprocal matings of FE resistant and susceptible selection-line animals, were used to generate four outcross families. The resulting half-sib progeny were artificially challenged with sporidesmin to phenotype their FE traits measured in terms of their serum levels of liver-specific enzymes, namely gamma-glutamyl transferase and glutamate dehydrogenase. In a primary screen using selective genotyping on extreme progeny of each family, a total of 244 DNA markers uniformly distributed over all 26 ovine autosomes (with an autosomal genome coverage of 79–91%) were tested for linkage to the FE traits. Data were analysed using Haley–Knott regression. The primary screen detected one significant and one suggestive QTL on chromosomes 3 and 8 respectively. Both the significant and suggestive QTL were followed up in a secondary screen where all progeny were genotyped and analysed; the QTL on chromosome 3 was significant in this analysis.     

Higher-level salamander relationships and divergence dates inferred from complete mitochondrial genomes

Phylogenetic relationships among the salamander families have been difficult to resolve, largely because the window of time in which major lineages diverged was very short relative to the subsequently long evolutionary history of each family. We present seven new complete mitochondrial genomes representing five salamander families that have no or few mitogenome records in GenBank in order to assess the phylogenetic relationships of all salamander families from a mitogenomic perspective. Phylogenetic analyses of two data sets—one combining the entire mitogenome sequence except for the D-loop, and the other combining the deduced amino acid sequences of all 13 mitochondrial protein-coding genes—produce nearly identical well-resolved topologies. The monophyly of each family is supported, including the controversial Proteidae. The internally fertilizing salamanders are demonstrated to be a clade, concordant with recent results using nuclear genes. The internally fertilizing salamanders include two well-supported clades: one is composed of Ambystomatidae, Dicamptodontidae, and Salamandridae, the other Proteidae, Rhyacotritonidae, Amphiumidae, and Plethodontidae. In contrast to results from nuclear loci, our results support the conventional morphological hypothesis that Sirenidae is the sister-group to all other salamanders and they statistically reject the hypothesis from nuclear genes that the suborder Cryptobranchoidea (Cryptobranchidae + Hynobiidae) branched earlier than the Sirenidae. Using recently recommended fossil calibration points and a “soft bound” calibration strategy, we recalculated evolutionary timescales for tetrapods with an emphasis on living salamanders, under a Bayesian framework with and without a rate-autocorrelation assumption. Our dating results indicate: (i) the widely used rate-autocorrelation assumption in relaxed clock analyses is problematic and the accuracy of molecular dating for early lissamphibian evolution is questionable; (ii) the initial diversification of living amphibians occurred later than recent estimates would suggest, from the Late Carboniferous to the Early Permian (294 MYA); (iii) living salamanders originated during the Early Jurassic (183 MYA), and (iv) most salamander families had diverged from each other by Late Cretaceous. A likelihood-based ancestral area reconstruction analysis favors a distribution throughout Laurasia in the Early Jurassic for the common ancestor of all living salamanders.     

Attraction independent of detection suggests special mechanisms for symmetry preferences in human face perception

Symmetrical human faces are attractive and it has been proposed that humans have a specialized mechanism for detecting symmetry in faces and that sensitivity to symmetry determines symmetry preferences. Here, we show that symmetry preferences are influenced by inversion, whereas symmetry detection is not and that within individuals the ability to detect facial symmetry is not related to preferences for facial symmetry. Taken together, these findings suggest that symmetry preferences are indeed driven by a mechanism that is independent of conscious detection. A specialized mechanism for symmetry preference independent of detection may be the result of specific pressures faced by human ancestors to select high-quality mates and could support a modular view of mate choice. Unconscious mechanisms determining face preferences may explain why the reasons behind attraction are often difficult to articulate and demonstrate that detection alone cannot explain symmetry preferences.     

Novel method for identifying individual cetaceans using facial features and symmetry: A test case using dolphins

Individual identification plays a major role in our understanding of the biology, ecology and behavior in cetaceans. Being able to tell individuals apart can provide invaluable insight into basic biological and scientific questions, but is also highly relevant to science‐based conservation. Given the importance of individual identification, it appears vital to improve existing identification methods and find new ones. Here, we present a novel identification method of using facial information, with common bottlenose dolphins (Tursiops truncatus) as a case study. In dolphins, dorsal fins are typically used for identification, but not all individuals or species are sufficiently marked. We show that facial features in bottlenose dolphins are long‐term and consistent across the left and right sides, and may enable calves (which tend to have unmarked fins) to be re‐identified after weaning, thus increasing cross‐generational knowledge. This novel method can complement dorsal fin identification by helping document mark changes over time and reduce false negative or positive errors. It also shows that current identification methods can still be improved. With increasing prevalence of digital photography and computer‐aided matching, it may become more viable to use ‘unconventional’ means of identification. We encourage other researchers to explore their photographic records for similar discoveries.     

Synaptic mechanisms of central control of motoneuronal activity in the facial nerve nucleus

The responses of motoneurons of the facial nerve nucleus (FNN), evoked by stimulations of the oculomotor nerve nucleus, Edinger-Westphal's nucleus,substantia nigra, and entopeduncular nucleus, were studied in acute experiments on anesthetized and immobilized cats. The FNN motoneurons were identified by their antidromic activation after stimulation of various branches of the facial nerve. Stimulation of the oculomotor nerve nucleus, Edinger-Westphal's nucleus, and ipsi- or contralateral parts of thesubstantia nigra evoked mono- and polysynaptic EPSP in the FNN motoneurons, while stimulation of the entopeduncular nucleus elicited only polysynaptic EPSP. The influences from the above structures were shown to converge on the same FNN motoneurons. The findings are discussed considering morphological peculiarities of the afferent inputs to the FNN.Neirofiziologiya/Neurophysiology, Vol. 27, No. 2, pp. 116–125, March–April, 1995.     

Re-evaluating the relationship between pathogen avoidance and preferences for facial symmetry and sexual dimorphism: A registered report

Over the past decade, a small literature has tested how trait-level pathogen-avoidance motives (e.g., disgust sensitivity) and exposure to pathogen cues relate to preferences for facial symmetry and sexual dimorphism. Results have largely been interpreted as suggesting that the behavioral immune system influences preferences for these features in potential mates. However, findings are limited by small sample sizes among studies reporting supportive evidence, the use of small stimulus sets to assess preferences for symmetry and dimorphism, and design features that render implications for theory ambiguous (namely, largely only investigating women's preferences for male faces). Using a sample of 954 White young adult UK participants and a pool of 100 White young adult stimuli, the current registered report applied a standard two-alternative forced-choice approach to evaluate both men's and women's preferences for both facial symmetry and dimorphism in both same- and opposite-sex targets. Participants were randomly assigned to either a pathogen prime or a control prime, and they completed instruments assessing individual differences in pathogen avoidance (disgust sensitivity and contamination sensitivity). Results revealed overall preferences for both facial symmetry and dimorphism. However, they did not reveal a relation between these preferences and disgust sensitivity or contamination sensitivity, nor did they reveal differences in these preferences across control and pathogen prime conditions. Null results of pathogen-avoidance variables were consistent across participant sex, target sex, and interactions between participant sex and target sex. Overall, findings cast doubt on the hypothesis that pathogen-avoidance motives influence preferences for facial symmetry or dimorphism.