bluuebunny/crossref_metadata_2025_split huggingface dataset:
Introduction
Authors: Møller Anders Pape , Gregersen Jens 
Published: November 2023

Abstract
When Darwin published On the origin of species by means of natural selection in 1859 he was basically able to account for the evolution of apparently adaptive characters and the process of speciation by means of natural selection. Variation in characters between individuals (which later became known as phenotypic variation), resource limitation, and the resulting non-random association between the expression of characters and a com¬ ponent of fitness were supposed to give rise to changes in the average character value. With the work of Mendel it was established that there was an association between phenotype and genotype, and differential fitness among phenotypes resulted in micro-evolutionary changes in gene frequencies.
Male mating advantages
Authors: Møller Anders Pape , Gregersen Jens 
Published: November 2023

Abstract
The primary driving force in sexual selection is non-random variation in mating success. For example, males with the most extreme secondary sexual characters may enjoy a mating advantage that results in an association between the expression of a sex trait and a fitness component. However, it is usually forgotten that sexual selection may take place at a number of different stages of the reproductive cycle, and that mating success is but one selection component, perhaps not even the most important one. The several components of sexual selection are briefly reviewed in section 4.2.
In section 4.3 of this chapter I summarize the evidence for the action of different sexual selection components in the barn swallow. More specifically, I describe the relationship between the tail length of males and:
Paternal care and male ornamentation
Authors: Møller Anders Pape , Gregersen Jens 
Published: November 2023

Abstract
Measurement of indirect fitness benefits through sexual selection are simplified in the absence of obvious direct fitness benefits such as parental care (see Chapter 2). Analysis of the relative contribution of direct and indirect fitness benefits through mate choice quickly becomes difficult when both components are present. The expression of a secondary sexual character may reflect indirect fitness benefits such as male attractiveness or superior genetic constitution, but the extent of paternal care may also be reflected in the expression of a male sex trait. Therefore, the problem is to determine whether the expression of the secondary sex trait reflects direct or indirect fitness benefits to the female.
Sexual size dimorphism and female ornaments
Authors: Møller Anders Pape , Gregersen Jens 
Published: November 2023

Abstract
In many animal species males differ in size from females. For example, females are considerably larger than males in many invertebrates, fish, amphibians, and reptiles, whereas males are larger than females in most birds and mammals (Darwin 1871 ). Why is this the case? Size differences between the two sexes are most readily explained by selection processes affecting individuals differently (section 12.2). Sexual size dimorphism may result from natural or sexual selection, as already emphasized by Charles Darwin (1871). Natural selection will affect the morphology of males and females both during reproduction and the non-reproductive period. For example, males and females may have slightly different foraging behaviour and habitat choice, and the different natural selection pressures under two kinds of environmental conditions may result in sexual differences in morphology. Intersexual competition for food resources may thus lead to sexual size dimorphism due to natural selection acting on heritable variation in morphology.
The evolution of polygyny in primitively eusocial polistine wasps with special reference to the genus ropalidia
Authors: Itô Yosiaki 
Published: November 2023

Abstract
The eusocial Vespidae can be divided into two broad categories, the primitively eusocial and the highly eusocial. Primitively eusocial species lack morphologically distinct queens. Although their ‘queens’ (inseminated and overwintered females in temperate species and major egg-layers in tropical species) are often larger than ‘workers’, their sizes overlap and workers have opportunities for personal reproduction (Ross and Matthews 1991). On the other hand, queens of highly eusocial species are distinguishable morphologically from workers, and the latter, as a rule, cannot lay diploid, female eggs. Most species of the subfamily Vespinae are highly eusocial (Matsuura 1991), all known species of the subfamily Stenogastrinae are primitively eusocial (Turillazzi 1991), while the subfamily Polistinae contains both primitively and highly eusocial species (Jeanne 1991; Gadagkar 1991; Reeve 1991). Within the Polistinae, we can distinguish two subgroups, the independent-founding species, in which colonies are initiated by one or several inseminated foundresses (queens), independently of any uninseminated females (workers), and the swarm-founding species, in which a colony is founded by a swarm containing a small number of queens and a large number of workers (Jeanne 1980).
Annual Variation In Fitness Components
Authors: Lank David B 
Published: November 2023

Abstract
Long term studies allow examination of a population’s response to a range of naturally occurring environmental conditions. Fluctuation in selective regime, on an appropriate time scale, is a potential mechanism for maintaining genetic variation in a population. The work at La Perouse Bay began in 1968, providing up to 25 breeding seasons’ data with which to assess the selective regime and the birds’ values for various components of fitness. We can determine whether patterns are relatively robust or highly sensitive to environmental conditions, and ascribe some of the total variation in characteristics to environmental or other variables acting on the population. We first outline the major factors which vary among seasons, then present data on the annual variability of fitness components and attempt to correlate this variation with one or more of these factors.
Age effects
Authors: Lank David B , Rockwell Robert F 
Published: November 2023

Abstract
A population’s potential ecological and evolutionary dynamics are determined in large measure by its life history strategy. By strategy, we mean those ‘coadapted traits designed, by natural selection, to solve particular ecological problems’ (Stearns 1976). A life-history strategy includes age-specific schedules of breeding propensity, reproductive success and survivorship. Combined, these parameters determine the lifetime reproductive success of individuals. This chapter describes the age-specific patterns of the fitness components for the Lesser Snow Goose, and considers the implications of these patterns on the ecology of the species.
Fish as prey: numbers, behaviour, and availability
Authors: Kruuk Hans 
Published: November 2023

Abstract
Most of the otter prey species in Shetland were least active by day, and at low tide, when they were hiding and were therefore easiest to catch for a foraging otter. Butterfish and shore crabs were more common than eelpout and rocklings, which were the species taken most by otters. In Shetland otters selected the larger individuals from prey populations, but elsewhere they took non-selectively from the bottom-living prey species. The main prey species in Shetland lived in different, well-separated habitats along the coast, and this was likely to affect the size of ranges which otters needed to exploit such prey. There was a glut of potential prey in midsummer, and fish were scarce and relatively small during late winter and spring. Sites from which we repeatedly removed all fish were repopulated within a day, providing otters with places for sustained harvesting. Predators may have major effects on communities of prey species, and otters took a high proportion from populations of salmonidfish in Scotland, but the effect of otters on fish populations along the Shetland shore was probably small.
Otters fishing: hunting behaviour and strategies
Authors: Kruuk Hans 
Published: November 2023

Abstract
The usual hunting behaviour of otters in the sea consisted of swimming along the surface in daytime, diving in shallow water, and capturing small fish from their hiding places. Swimming speeds are described, as well as diving, handling, and eating of prey. Occasionally otters captured other animals such as aquatic birds, and they caught rabbits in their burrows. Otters were active during the day in Shetland and at night in many other places, because of the activity pattern of their prey species, the majority of which were caught when inactive. In the sea there was also a tidal effect, with otters foraging least during high tide. Success rates appear to be partly predetermined (otters fishing when there is a maximum likelihood of success). Differences in success rates between areas appeared to be related to prey size, and there was little variation in success rates between different depths of water and between seasons, with overall diving success around 27per cent in the sea.
Populations,survival,and mortality
Authors: Kruuk Hans 
Published: November 2023

Abstract
Different ways of assessing numbers of otters are discussed, including direct observation, spraint surveys (which should be treated with caution), stratified density sampling of otter holts, and the use of radionuclide-labelled spraints. Densities were found of one adult per 1−2 km ofcoast (Shetland) or 15 km of stream (north-east Scotland). Mortality patterns and age structure of populations are discussed; otters die relatively young, with a mean adult life expectancy of 3.1 years, and mortality rate gradually increases with age. Mercury is the only present-day pollutant on which we have information, which is likely to play a significant role in causing mortality amongst Scottish and Shetland otters. Prey availablity appears to affect both mortality and recruitment very strongly, but in different ways: mortality in spring, recruitment in summer. Females may deliberately abandonyoung cubs.
Systematics and phylogeny
Authors: Zann Richard A 
Published: November 2023

Abstract
Zebra Finches belong to the estrildine group of finches of which there are approximately 124 species found mainly in the tropical and subtropical parts of Africa, India, South-East Asia, Australia and Melanesia. Estrildines are the only granivorous group of passerines endemic to Australia and authorities recognise 18 species, of which the Zebra Finch is the most widespread and numerous.
Continuous time and age-structure
Authors: Hassell Michael P 
Published: November 2023

Abstract
Most of the host-parasitoid systems explored so far in this book have involved coupled interactions with discrete and synchronised generations. Such discretegeneration life cycles are most frequently found in univoltine species in temperate regions where seasonality often synchronises populations and provides a natural interval between the appearance of successive generations. Seasonality also often synchronises the appearance of the first generation of multivoltine species within a year, although successive generations throughout the season tend to show progressive overlap of their life-cycle stages. Focusing on discrete-generation life cycles does not mean that age-structure is necessarily neglected in these models. For example, the combination of parasitoids and additional host density dependence requires specific assumptions about the order with which these occur in the host’s life cycle, which is then reflected in the model structure (Chapter 3, p. 46). Another example, in this case with an explicit treatment of age-structure, was discussed in Chapter 4, p. 90, involving the stabilising effects of phenological asynchrony between hosts and parasitoids within a single generation period.
Metapopulations of hosts and parasitoids
Authors: Hassell Michael P 
Published: November 2023

Abstract
The spatial interactions between hosts and parasitoids discussed in Chapter 4 assume complete mixing of the dispersing individuals of both populations at least once during each generation period. It is as if the individuals enter a ‘global pool’ and then redistribute themselves amongst the patches according to particular rules. This implies that individuals are able to disperse widely across their entire habitat which, in turn, restricts the spatial scale that is appropriate for such systems.
Epilogue
Authors: Aiken S Robert , Leigh Colin H 
Published: November 2023

Abstract
Deforestation has a long and very complex history, most of which remains to be written. Systematic interest in the subject spans little more than a century, beginning with G. P. Marsh’s seminal Man and Nature (1864/1965). Palynological and archaeological evidence suggests that anthropogenic forest change can be traced to at least the early Holocene, while literary and other sources reveal many examples of deforestation since ancient times. Consider a few greatly simplified examples.
The role of the insulin-like growth factors in the nervous system
Authors: Sara Vicki R 
Published: November 2023

Abstract
The importance of serum and tissue extracts for the growth of cells in culture has been recognized since early this century when, for example, Carrel (1913) demonstrated that embryo extracts were necessary for the growth of cells in culture. The use of tissue culture in the field of neurobiology was initiated by Ross Harrison, who observed the outgrowth of embryonic tadpole neuronal fibres from cells grown on clotted lymph from adult frogs (Harrison 1907). His observations in vitro confirmed the neuronal theory proposed by Ramon y Cajal. Almost a half century later, Rita Levi-Montalcini and Victor Hamburger (1951) found that tumour tissue secreted a substance which stimulated neurite outgrowth from chick embryo. Rita Levi-Montalcini, together with Stanley Cohen, continued this work, which culminated in the pioneering discovery of nerve growth factor. Until recently, nerve growth factor was believed to be specific for the growth of sympathetic and sensory neurones, so that the analogous growth factor for the central nervous system remained elusive for many years.
Descriptive Text
Authors: Keay R W J 
Published: November 2023

Abstract
This is a family of the Gymnosperms which diffe from the Angiosperms ( the flowering plants) by not having the ovules enclosed in an ovary. The only gymnosperm indigenous in Nigeria is in this family, but several other genera in other gymnosperm families have been introduced. The Podocarpaceae is a family of 7 genera, largely in the southern hemisphere.
Phasic development in palms
Authors: Tomlinson P B 
Published: November 2023

Abstract
Palms have morphological attributes that facilitate developmental and demographic study. This chapter outlines these features of growth and construction, all of which are elaborated in later chapters. Growth processes themselves are complex; the essays on stem vasculature demonstrate this, but also shows that constructional principles can be recognized. The architecture of palms can be approached because simple rules that govern and sometimes constrain development can be recognized.
Embryo and seedling
Authors: Tomlinson P B 
Published: November 2023

Abstract
The seedling phase of development of the palm may be defined as beginning with the enlargement of the embryo some time after the fruit is mature (germination), until the exhaustion of the endosperm reserves of the seed itself, a point difficult to establish in the absence of any morphological change. An alternative would be to consider expansion of the first bladed seedling leaf (eophyll) as the end of seedling development, even though the endosperm might not be exhausted. Robertson (1983a) divided germination in Jubaeopsis into five stages, beginning with the emergence of the seedling from the seed and ending with the appearance of the first eophyll (first bladed leaf). The biochemical and structural changes which occur in the embryo and endosperm during germination are discussed later. ‘Embryology’ in the broad sense, i.e. including all phases of micro- and mega-gametophyte development as well as embryo development, is not considered in this book (but cf Robertson 1976a,b,c for a modern example).
Establishment phase
Authors: Tomlinson P B 
Published: November 2023

Abstract
The post-seedling phase of development is a highly significant one in the ontogeny of the palm because it is the foundation for the mature primary axis. For this reason, Tomlinson and Zimmermann (1966b) coined the term ‘establishment growth’ for the developmental changes involved in this phase. This term was used in preference to the older Erstarckungswachstum (lit. ‘strengthening growth’) of earlier German authors, e.g. Troll (1936) because the changes are not merely mechanical, but also physiological. Establishment growth occurs to some extent in all vascular plants, but only in monocotyledons is it pronounced, even in those which have secondary thickening.
Vascular anatomy of the stem
Authors: Tomlinson P B 
Published: November 2023

Abstract
Palms, because of their simple architecture, provide ideal objects for the study of economy and efficiency in organic construction. They have unbranched axes, each of which supports a terminal tuft of appendages (leaves), each leaf supported by a basal sheath. The palm stem represents the reinforced concrete of the structural engineer (Fig. 6.1), since its tissues can be thought of as a series of axially-orientated vascular bundles (steel rods) embedded in a parenchymatous ground tissue (concrete matrix). Unlike the engineer’s reinforced concrete, the vascular bundles of the palm stem are not necessarily uniformly distributed, but usually concentrated toward the stem periphery for maximum efficiency. The stem of many palms has an additional mechanical feature, unfamiliar to human engineers, in that it can increase its stiffness with age. This is a very efficient way of growing because it means that the palm is not excessively overbuilt. It is as if an engineer could design a struture that becomes increasingly stronger directly as increasing strength is required. If the life span of the structure is shortened accidentally by some factor other than mechanical failure, the initial investment in the aborted structure is minimized. In terms of the palm tree this ‘saved’ investment can be diverted to more appropriate ecological events, such as growing in height, or in reproduction.
Palm stem—mechanics, age determination, and hydraulics
Authors: Tomlinson P B 
Published: November 2023

Abstract
The palm stem, as in all erect woody axes, serves the three-fold functions of transport, mechanical support, and storage. The transport system moves water and mineral nutrients in the xylem from the roots to the leaves, and also moves assimilates (sugars) in the phloem from the leaves (‘sources’) to regions where they are either metabolized or stored (in ‘sinks’) such as root and shoot apices, developing inflorescences and fruits, and storage parenchyma. The mechanical function of erect axes is to support the leafy crown and appendages, and depends on efficient distribution of sclerenchyma. The storage function is evident as starch grains which accumulate in the ground parenchyma. The three functions are clearly separated in the differentiation between different kinds of stem tissues visible microscopically in a transverse section (Plate 7). Individual fibrovascular bundles represent the combined conducting-mechanical system; however, mechanical fibres are clearly segretated from the conducting cells of xylem and phloem. The parenchymatous ground tissue represents not only the storage tissue, but the matrix within which the fibrovascular system is embedded.
Conclusions
Authors: Lavocat René 
Published: November 2023

Abstract
As discussed by A. E. Wood in the introduction to this book, the question of the Africa-South America connection, evidenced by more or less apparent parallels in the flora and fauna of both continents, took on an entirely new dimension when plate tectonics demonstrated that today’s distinct continents were once united in a single mass, before being slowly separated by continental drift. For many years, the apparent similarities between the various faunal and floral elements were used as key arguments supporting, among other things, the existence of what was called the Gondwana continent. Now that we have indisputable geological proof of this phenomenon, it is probably less important to provide biological evidence for it. In fact, we should use our knowledge of the existence of the continent to understand further the biological relationships. Nevertheless, plate tectonics, particularly during transition stages, may not always reveal the precise timing or extent of continental movements. For example, the presence of a shallow epicontinental sea, which would not be revealed by plate tectonics, could have restricted migrations routes and hampered the migration of some animals. Clearly, such a sea would have been as difficult to cross as a deep ocean for small terrestrial vertebrates, but not for huge amphibian hadrosaurians.
Reconstructing phylogenetic trees and ancestral character states
Authors: Harvey Paul H , Pagel Mark D 
Published: November 2023

Abstract
We described in the previous chapter how living organisms come to contain information about their evolutionary history, and why this means that comparative analyses must utilize phylogenetic information. This chapter asks what phylogenetic information we need for comparative tests, and how we might obtain it. It will become evident that although defining the information that we need is fairly straightforward, getting it is another matter. In fact the overriding message of this chapter will be that in the absence of a good fossil record we can never be sure of evolutionary history. We often produce quite different pictures of the past by basing our reconstructions on evolutionary models that make different assumptions about the roles of processes such as natural selection and genetic drift. An important task for biologists is to define which models are based on the most biologically realistic assumptions.
Conclusion
Authors: Harvey Paul H , Pagel Mark D 
Published: November 2023

Abstract
The comparative method that we have described in this book depends on the interplay among phylogenetic inheritance, chance events, and adaptation to contemporary environments. To consider only one of these processes alone is to lose much that has intrigued evolutionary biologists since Darwin. Yet, although the comparative method has been in constant use over the past century or so, we can only echo Ridley’s (1983n) wonder that it remained virtually unchanged from Darwin’s time until a decade ago. Meanwhile, population genetics and experimental investigations had forged ahead. We hope that this book has shown why the quotation which opened our first chapter should soon become history: … ‘we must learn to treat comparative data with the same respect as we would treat experimental results’ (Maynard Smith and Holliday 1979, p. vii). We can already treat properly analysed comparative results with the same respect that we treat experimental results. And, as we have seen, each has a crucial role to play in the development of our field.