Ontogeny

BACKGROUND/AIMS: BSEP, MRP2, and MDR3 are major hepatic canalicular transporters mediating bile secretion. Their expression in human liver during development has not been reported. METHODS: Human liver samples from fetus at gestational age 14–20 weeks, ...

Crocodylians exhibit a fascinating diversity of terrestrial gaits and limb motions that remain poorly described and are of great importance to understanding their natural history and evolution. Their musculoskeletal anatomy is pivotal to this diversity and yet only qualitative studies of muscle-tendon unit anatomy exist. The relative masses and internal architecture (fascicle lengths and physiological cross-sectional areas) of muscles of the pectoral and pelvic limbs of American alligators (Alligator mississippiensis Daudin 1801) were recorded for an ontogenetic series of wild specimens (n = 15, body masses from 0.5 to 60 kg). The data were analysed by reduced major axis regression to determine scaling relationships with body mass. Physiological cross-sectional areas and therefore muscle force-generating capacity were found to be greater in the extensor (anti-gravity) muscles of the pelvic limb than in the pectoral limb, reflecting how crocodylians differ from mammals in having greater loading of the hindlimbs than the forelimbs. Muscle masses and architecture were generally found to scale isometrically with body mass, suggesting an ontogenetic decrease in terrestrial athleticism. This concurs with the findings of previous studies showing ontogenetic decreases in limb bone length and the general scaling principle of a decline of strength : weight ratios with increasing size in animals. Exceptions to isometric scaling found included positive allometry in fascicle length for extensor musculature of both limbs, suggesting an ontogenetic increase in working range interpreted as increasing postural variability – in particular the major hip extensors – the interpretation of which is complicated by previous described ontogenetic increase of moment arms for these muscles.

Jaw adductor hypertrophy, or the presence of enlarged jaw-closing muscles, has arisen several times independently in African clariid catfsh. Previous work has demonstrated that species characterized by enlarged jaw adductors may have unusual ways of foraging such as terrestrial foraging and prey capture, and often include a large proportion of hard and terrestrial prey in their diet. However, relatively little is known
about species of the genus Clariallabes with an intermediate degree of jaw adductor hypertrophy. In the present study we present data on head shape and diet for a range of sizes of specimens of a poorly known species of Clariallabes, C. melas. Our data show that growth patterns in this species and the previously studied C. longicauda are similar in some ways (e.g. positive allometry of the growth of the jaw muscles) but different
in others (negative allometry in hyoid width). However, C. melas has a smaller head for its body size in all dimensions. Due to the large number of empty stomachs we encountered, dietary data remain preliminary, but suggest a varied diet including both hard and soft prey. Our data show that a large amount of variation in
head shape may exist even among related species and that species with jaw adductor hypertrophy generally show positive allometry in the growth of the jaw adductors and associated structures. Whether jaw muscle hypertrophy is an adaptive trait in clariid catfsh awaits further comparative analyses testing for the evolutionary association between jaw adductor hypertrophy and the inclusion of hard prey into the diet.

Tropical ecosystems have a great organismal diversity. However, the trophic relations of many components are poorly understood and this is particularly the case for caecilian amphibians. We analysed spatial and temporal aspects of the diet of a caecilian (Ichthyophis cf. kohtaoensis) at a field site in North-eastern Thailand (Mekong valley, Khemmarat District, Ubon Ratchathani Province). This is the first study to include both aquatic larvae and terrestrial adult stages of any caecilian. Larval I. cf. kohtaoensis feed exclusively on aquatic invertebrates (e.g., dragonfly larvae, water beetles and clam shrimps). A comparison of potential prey taxa available indicates that larval I. cf. kohtaoensis prefer benthic prey. Terrestrial I. cf. kohtaoensis consume mostly soil invertebrates such as megascolecid earthworms, ants and termites (soil ecosystem engineers). Numerically and in terms of their frequency of occurrence, these major prey groups varied strongly between seasons. Scarabaeid beetle larvae, oribatid and mesostigmatid mites and occasionally microhylid frogs were also recorded in the diet. During ontogeny, I. cf. kohtaoensis move from an aquatic to terrestrial existence. Despite this, accompanying changes in trophic position are superficial because both stages are carnivorous generalists. In this regard, they are more similar to salamanders than frogs with biphasic life history cycles.

More than 150 years ago, in 1866, Ernst Haeckel published a book in two volumes called Generelle Morphologie der Organismen (General Morphology of Organisms) in the first volume of which he formulated his biogenetic law, famously stating that on-togeny recapitulates phylogeny. Here, we describe Haeckel's original idea as first formulated in the Generelle Morphologie der Organismen and later further developed in other publications until the present situation in which molecular data are used to test the "hourglass model," which can be seen as a modern version of the biogenetic law. We also tell the story about his discovery, while traveling in Norway, of an unknown organism, Magosphaera planula, that was important in that it helped to precipitate his ideas into what was to become the Gastraea theory. We also follow further development and reformulations of the Gastraea theory by other scientists, notably the Russian school. Elias Metchnikoff developed the Phagocytella hypothesis for the origin of metazoans based on studies of a colonial flagellate. Alexey Zakhvatin focused on deducing the ancestral life cycle and the cell types of the last common ancestor of all metazoans, and Kirill V. Mikhailov recently pursued this line of research further.

KEYWORDS heterochrony, Magosphaera planula, ontogeny, phylogeny

Isognomon alatus is a sessile intertidal bivalve species that attaches to hard substrata. Within the Florida Keys, where tidal ranges are usually less than 1 m, settlement sites only a few centimetres apart experience drastically different tidal microhabitats. These varying conditions may create morphological gradients that can complicate taxonomic designations. To quantify and characterize the conchological effects of this microhabitat gradient and estimate the degree to which these effects can confuse species identification, I. alatus was studied in relation to tidal position using geometric morphometrics. Isognomon alatus was only found at positions 0.4 m below the highest tide mark, positions exposed to air less than 80% of the time. Below this limit specimen size, immersion time, and area available all covary. Shape differences due to ontogeny were removed using regression and the remaining phenotypic variation within these specimens is significantly correlated with the measured habitat conditions, immersion time being the more robust predictor. The observed phenotype effects are small but can influence species identification. Species assignment tests between I. alatus and the morphologically similar IndoPacific I. ephippium ranged in accuracy from 98 to 90% across microhabitat condition

The anatomy of the New Zealand tuatara has been examined extensively by anatomists and palaeontologists because it represents the only living member of the Rhynchocephalia, a group of reptiles that were successful during the time of the dinosaurs. The tuatara is also of interest because of its specialized teeth and a forward chewing stroke that it uses to rip food apart. However, despite several detailed descriptions of the skull, there has been little work on how the individual bones of the skull fit together. Here we provide the first joint by joint ...

Four juvenile specimens referable to Pinacosaurus grangeri (Ankylosauria: Dinosauria) are described from the Campanian (Upper Cretaceous) locality Bayan Mandahu in northern Inner Mongolia Autonomous Region (People’s Republic of China). All the specimens preserve the skulls as well as, in some cases, mandibles, postcrania, and osteoderm. They are not taphonomically deformed by expanding matrix distortion, unlike many Gobi specimens, including the holotype of P. grangeri. Bayan Mandahu is also the type locality for Pinacosaurus mephistocephalus. The proximity in space and time of these two closely related species warrants a generic and specific revision for Pinacosaurus. The distinction of the two species is based on characters of the squamosal dermal elaborations, cranial roof posterior to the orbits, premaxillary notch, and distal margin of the ilium. Although a relatively well-represented ankylosaur taxon, the phylogenetic position of Pinacosaurus has not been unequivocally resolved. A new analysis recovers Pinacosaurus as the most basal member of the Ankylosaurinae.

Tyrannosaurs, the group of dinosaurian carnivores that includes Tyrannosaurus rex and its closest relatives, are icons of prehistory. They are also the most intensively studied extinct dinosaurs, and thanks to large sample sizes and an influx of new discoveries, have become ancient exemplar organisms used to study many themes in vertebrate paleontology. A phylogeny that includes recently described species shows that tyrannosaurs originated by the Middle Jurassic but remained mostly small and ecologically marginal until the latest Cretaceous. Anatomical, biomechanical, and histological studies of T. rex and other derived tyrannosaurs show that large tyrannosaurs could not run rapidly, were capable of crushing bite forces, had accelerated growth rates and keen senses, and underwent pronounced changes during ontogeny. The biology and evolutionary history of tyrannosaurs provide a foundation for comparison with other dinosaurs and living organisms.

Blastoids (phylum Echinodermata; class Blastoidea) pass through a stage during growth in which the oral surface of the minute theca is composed of five oral plates only. The evidence that these thecae, which lack hydrospires, deltoids and lancet plates, are juvenile blastoids is that they occur together with mature blastoids and vice versa; they have growth lines on the exterior of the plates; and the outlines of their thecal plates are congruent with the earliest growth lines of the thecal plates of blastoids. It is proposed that this growth stage should be referred to as the passalocrinid stage, because the juvenile blastoids at this stage have previously been referred to Passalocrinus, originally described as a monocyclic crinoid. Coronoids also pass through a stage comparable to the passalocrinid stage of blastoids. Copyright © 2005 John Wiley & Sons, Ltd.

For a long time, Gilbert Simondon's work was known only as either a philosophy restricted to the problem of technology or as an inspirational source for Gilles Deleuze's philosophy of difference. As Simondon's thinking is now finally in the process of being recognized in its own right as one of the most original philosophies of 20 th century, this also entails that some critical work needs to be done to disentangle it from an all too hasty identification with (or even subsumption under) Deleuzian categories. While both Simondon and Deleuze have made crucial contributions towards a theory of differential individuation that significantly diverges from other authors associated with French poststructuralism insofar as they insist on the dynamic and vital dimension of difference, they also differ on crucial points. Whereas Simondon sees the process of becoming as transductive amplification, and Deleuze theorizes it as intensifying involution, leading to two notably distinct concepts of difference.

Two decades ago, the collective effort of numerous scientists laid the foundation of a new synthesis of physical anthropology, paleoneurobiology, ethology, biocultural evolution, systematic musicology, semiotics, historical linguistics, and developmental psychology in "The Origins of Music" (MIT Press, 2000). The purpose of this was to overcome the lack of archaeological evidence for the prehistoric development of music. This volume, "The Evolution of Music", updates these fields and adds to them a few other new ones: organology, musicological analysis, geomusicology, demography, information theory, statistical modeling, paleo-aesthetics, paleo-phonology, and biological motion. In addition, we address a number of interdisciplinary problems, especially the growing conviction amongst Western ethnomusicologists that humanities and sciences are fundamentally split, and that the scientific approach somehow introduces an "anti-humanitarian" bias.

In Eastern Christianity novitiate is a period of learning to experience the presence of God in one's life and the world. Novices follow the hesychast prayer, a mystical tradition that leads them to an experiential knowledge of God. In this paper, I argue that novitiate should be regarded as a complex learning process involving specific assemblages of contextual, cognitive, body-sensory and emotional aspects. By educating their attention and emotion novices learn to see beyond and within reality and thus discover the potentiality of people and things ‘in the likeness of God’. Religious transmission happens not only through embodied practice and the active acquisition of religious knowledge but, more importantly, through the work of the imagination. Novices' orientation towards the transcendent requires an expansion of the imaginative capacities beyond their ‘routine’ functioning. Imagination could be thus seen as a key cognitive capacity through which they learn to experience God.

Every biological form can be explained as the product of two different processes: the development from the egg (also known as “ontogenesis”) and the evolution from the ancestors (the “phylogenesis”). Charles Darwin, the father of evolutionism, recognized the importance of both processes to explain the variety of living creatures and their relationship, but only a few of his followers were aware of this theoretical connection. In this article we will try to understand how the evolutionist scientist Ernst Haeckel elaborate his embryological theories and, in particular, the well-known “theory of recapitulation”, also known as “biogenetic law”. Furthermore, we will try to discover the value of his famous drawings (real icons of embryological knowledge) and to recognize their philosophical references.

This is a draft for a long-awaited method of musicological analysis of music, designed for identification, classification, and interpretation of music structures found in recordings of solo musicking within any form of traditional music. This includes but is not limited to solo songs, instrumental solos, and leading parts (melody) in a monodic composition (e.g. a song with instrumental accompaniment), ranging from tonality of Western classical music to ekmelic (indefinite-pitch based) forms of musicking. The proposed method features novel formats of visualization of the analyzed music, of tabulation of the metrics collected with the help of existing software frequency analyzers, of matrix technique for identification of melodic intonations, of kinematic graphing of degrees in a musical mode, and of frustrum projection for convenient visualization of a musical mode.

Combining theory from cognitive semantics and pragmatics, this book offers both a new theoretical model and a new usage-based method for the under- standing of intersubjectivity, and how social cognition is expressed linguistic- ally at different levels of complexity. Bringing together ideas from linguistics and Theory of Mind, Vittorio Tantucci demonstrates the way in which speakers constantly monitor and project their interlocutor’s reactions to what is being said, and sets out three distinct categories of social cognition in first language acquisition and language change. He also shows how this model can be applied in different settings and includes a range of examples from languages across the globe, to demonstrate the cross-linguistic universality of the model. Additionally, the book offers insights into the gradient dimension of intersubjectivity in language evolution and across the autistic spectrum. Original and innovative, it will be invaluable for researchers in cognitive linguistics, pragmatics, historical linguistics, applied linguistics and cognitive psychology. Vittorio Tantucci is Lecturer in Linguistics at Lancaster University. His research combines diachronic and ontogenetic naturalistic data to shed light on the human ability to express social cognition at different levels of linguistic complexity.

Annotation. In the article is investigated speciesspecific
features in the initial stages of ontogeny, the variability of shoots morphology of the Urals alpine
Saussurea. It was found that the South Ural highland
populations of Saussurea are the isolated endemic
taxon, morphologically isolated from S. alpina,
S. controversa and S. uralensis. Differences between
S. igoschinae and S. uralensis manifested even in the
earliest stages of ontogeny. S. igoschinae South Ural
population need the special protection measures and
monitoring of populations.

Morphological changes in the ontogeny of sauropods are poorly known, making difficult to establish the systematic affinities of very young individuals. New information on an almost complete juvenile sauropod (SMA 0009) with an estimated total length of about 2 m, is here presented. The specimen was described as a diplodocid due to the presence of some putative synapomorphies of this group. However, recent further preparation revealed the absence of diplodocid characters and the presence of macronarian derived characters. In order to test the affinities of this specimen a phylogenetic analysis was conducted. The strict consensus tree recovers the specimen as a basal titanosauriform, in an unresolved relation with Brachiosaurus and Giraffatitan. Nevertheless, a brachiosaurid assignment is here suggested in base of the widely accepted monophyly of this group (only recovered when SMA 0009 is placed within this group). Although the existence of a new taxon cannot be completely ruled out, the combination of derived and plesiomorphic characters in the specimen suggest its assignment to Brachiosaurus. Sixteen extra steps are needed to place this specimen within Diplodocidae. The high cost to place this specimen within this group is due to the fact that several diplodocid characters are absent in SMA 0009, such as the absence of divided centroprezygapophyseal lamina in cervical vertebrae, procoelous anterior caudal centra, composed lateral lamina in anterior caudal vertebrae, elongated middle caudal vertebrae, short cervical ribs, and caudolateral projection of distal condyle of metatarsal I. Finally, the systematic position reveals few major ontogenetic transformations. These affect the pneumatic structures (e.g. change from simple pleurocoels in the cervical vertebrae to complex pleurocoels and the development of lateral excavations in the dorsal vertebrae) but also include unrecorded transformations of the neural spine (e.g. the development of the spinodiapophyseal lamina, the widening of the neural spines in the dorsal vertebrae) and allometric growth in some limb bones.

The pattern of acquisition of speech- and music-related skills during early stages of human infancy provides insight into the origins of language and music. Indiscriminate until shortly after birth, babies start gradually developing acoustic features in their vocalizations, as well as accompanying behaviors that make it possible to distinguish their attempts to speak from their attempts to sing. Comparative analysis of tonal organization of children's original (non-imitative) vocalizations in their developmental succession throughout the first 3 years of life casts light on several important acoustic features. These features play an important role in the separation of music from verbal skills and shaping the primordial music system the infant uses to address his/her musical needs.
Much of the existing scholarship commits a fundamental error by interpreting the earliest forms of human speech and music in terms of "adult" state of their mastery, regarding children's communication as a sort of "defective" imitation of adults' models. Moreover, such models are significantly biased towards Western classical music and Indo-European languages, which despite their cultural importance in the modern world, nevertheless, constitute only a small fraction of typology of tonal musical and phonological verbal organization. A much more comprehensive approach towards children's music and speech has been developed by Lev Vygotsky and his circle: Alexander Luria, Aleksei Leontyev, Alexander Zaporozhets, Peter Galperin, as well as Boris Teplov. They and their followers regarded children's speech and music as reflecting a child's own peculiar method of thinking. The Vygotskian approach shares much in common with that of Piaget and the neo-Piagetians, but offers an alternative framework for explanation of the dichotomy between language and music—based on the methodology of intonation theory by Boleslav Yavorsky and Boris Asafyev. This theory was implemented in the state program of obligatory education within all territories of the former USSR; it had passed deep scrutiny throughout many years of administration over a massive population, which resulted in creation of a special discipline of ear development that theoretically and practically dealt with the development of "musical hearing" as distinguished from "verbal hearing" throughout childhood. Unfortunately, much of this literature is unknown to Western developmental specialists. This chapter covers this gap, familiarizing English-speaking scholars with the unique perspective on early musical and verbal development by Soviet and modern Russian ear-training specialists, with special attention to the issue of absolute pitch.
Advances in the methodology of intonational analysis made possible an adequate description and deeper understanding of the principles that govern tonal organization of non-Western types of music—including those that are based on timbre rather than pitch. This approach can be effectively applied to the analysis of both, ethnological and developmental data—to identify the common patterns of ontogenetic and phylogenetic development.

Increasing fossil evidence surrounding the evolutionary origin of vertebrate limbs can be used to reconstruct the assembly of a limb ground-plan common to all tetrapods. The sequence of changes at the fin-to-limb transition can be compared to patterns of fin and limb ontogeny, and further comparisons can be made between phylogenetic changes at pectoral and pelvic levels. Such comparisons inform questions about the evolution of developmental autonomy (modularity). Limb evolution mostly concerns terminal additions and losses; from a developmental standpoint, these probably result either from minor adjustments to limb bud proportions or from the relative timing of gene expression or tissue growth. Evolutionary radiations of large clades are widely assumed to be marked by periods of rapid morphological diversification, raising further questions about the impact of restrictions imposed not only by ecology, but also by development and genetics. The early tetrapod data set is now large eno...

Background
Eurypterids are a diverse group of chelicerates known from ~250 species with a sparse Ordovician record currently comprising 11 species; the oldest fully documented example is from the Sandbian of Avalonia. The Middle Ordovician (Darriwilian) fauna of the Winneshiek Lagerstätte includes a new eurypterid species represented by more than 150 specimens, including some juveniles, preserved as carbonaceous cuticular remains. This taxon represents the oldest described eurypterid, extending the documented range of the group back some 9 million years.

Results
The new eurypterid species is described as Pentecopterus decorahensis gen. et sp. nov.. Phylogenetic analysis places Pentecopterus at the base of the Megalograptidae, united with the two genera previously assigned to this family by the shared possession of two or more pairs of spines per podomere on prosomal appendage IV, a reduction of all spines except the pair on the penultimate podomere of appendage V, and an ornamentation of guttalate scales, including angular scales along the posterior margin of the dorsal tergites and in longitudinal rows along the tergites. The morphology of Pentecopterus reveals that the Megalograptidae are representatives of the derived carcinosomatoid clade and not basal eurypterids as previously interpreted.

Conclusions
The relatively derived position of megalograptids within the eurypterids indicates that most eurypterid clades were present by the Middle Ordovician. Eurypterids either underwent an explosive radiation soon after their origination, or earlier representatives, perhaps Cambrian in age, remain to be discovered. The available instars of Pentecopterus decorahensis suggest that eurypterids underwent extreme appendage differentiation during development, a potentially unique condition among chelicerates. The high degree of appendage specialization in eurypterids is only matched by arachnids within chelicerates, supporting a sister taxon relationship between them.

A new dataset of the highest quality specimens of fully articulated, juvenile and mature exoskeletons of the Czech middle Silurian trilobite Aulacopleura koninckii offers improved resolution of original morphology by all measures considered. The degree of variation in both size and shape among later meraspid instars was constant, and suggesting targeted growth in both attributes. Size-related changes in the shape of the dorsal exoskeleton and of the segment-invariant cephalon were detected in the meraspid stage, but in the holaspid phase marked allometry was detected only in the trunk region, with the pygidium showing notable expansion in relative size. Meraspid cranidial allometry was subtle, with significant changes in instar form detectable only after several molts. This trilobite developed gradually throughout meraspid and holaspid ontogeny, with the synchronous cessation of trunk segment appearance and release at the onset of the holaspid phase. Precise development of shape and size occurs in the context of marked variability in the number of trunk segments at maturity, illustrating complex patterns of character variation within a species. A new systematic description establishes the synonymy of several subspecies with A. koninckii.