Temporal constraints on reproduction and growth in a seasonal environment

The variety of life forms is one of the most striking phenomena that have stimulated research in evolutionary biology and ecology over recent decades. The crucial role in defining the most characteristic features of living organisms is dedicated to so-called life history traits (Stearns 1992, Roff 2002). Biological species are characterized by several life history traits such as lifespan, rate of ageing, sexual size dimorphism, but also traits investigated in this work: body size, growth rate, mode of reproduction, and timing and synchrony of breeding. Those traits define functional features of species with consequences going far beyond simple classification. From individual to the ecosystem level, life history traits affect physiology, behaviour but also interactions between species (Davies et al. 2012). Hence, the knowledge about how life history traits evolve is central for understanding important scientific questions but also practical ecological or conservation issues (Allen 2006, Jørgensen et al. 2007, Heino et al. 2015). The great meaning and the potential of our understanding of the sources of evolution of life history traits for understanding ecosystem functioning is the main motivation of my research presented in this thesis. In my thesis I combine theoretical models and empirical work. I aimed at testing hypotheses on the evolution of life history traits in the context of one of the key life history compromises: the evolutionary trade-off between current and future reproduction (Williams 1966). My work was inspired by life histories of species living at a high-latitude Arctic ecosystem of Svalbard archipelago. The empirical part of my thesis, performed to test the predictions of my theoretical research, was conducted in Svalbard in years 2015 2020. The research questions regarding the evolution of body size, growth rate, mode of reproduction and, timing and synchrony of breeding presented in this thesis are oriented around the two subjects described below: the life history trade-off between current and future reproduction under temporal constraints generally and in a high latitude Arctic ecosystem particularly.Doktorgradsavhandlin

The Gebelein Region in the Third Intermediate and Late Periods

While relatively much is known of Gebelein in the second and third millennia BCE, as well as the Ptolemaic times, the role of the town of Per-Hathor and its surrounding in the Third Intermediate (c. 1076–747 BCE) and Late (c. 747–332 BCE) periods remains largely obscure. The aim of this paper is to examine the existing sources pertaining to the history of Gebelein with the particular focus on state activities in the area, diachronic changes in settlement pattern and sacral topography, as well as funerary landscape in the first three-quarters of first millennium BCE and analyse the available information in a regional context. For this, published and unpublished records are utilised, together with the results of the current field prospection in Gebelein

Is Doping of Cognitive Performance an Anti‐Herbivore Adaptation? Alkaloids Inhibiting Acetylcholinesterase as a Case

Historically, people who study interactions between plants and herbivores focused on the ecological costs and benefits of synthesizing secondary metabolites. These compounds have diverse functions including defenses against herbivores. Some plants produce alkaloids that act as acetylcholinesterase inhibitors, increasing both the level and duration of action of the neurotransmitter acetylcholine with potential toxic effects in insects and mammals. Yet, among a number of neuroactive plant chemicals, alkaloids that inhibit acetylcholinesterase (AIA) display nootropic activities, that is, positively affect cognition, learning, and memory in mammals. This creates a paradox: Neuroactive AIA, expected to punish herbivores, enhance cognition, learning, and memory. A prevailing view is AIA are pesticides that adversely affecting the nervous systems of herbivorous insects, and the positive influences in mammals are merely a by‐product of other functions. We review literature on the behavioral ecology of diet choice, food‐aversion learning, and neurophysiological actions of AIA in mammals to provide a more comprehensive view of the adaptive significance of AIA. These compounds act as anti‐herbivory defenses that influence flavor (taste plus odor) preference/aversion, the formation of memories, and the feeding behavior of mammalian herbivores. Thus, what appears from an insect standpoint to be an enigma makes sense for mammals: AIA enable mammalian herbivores to quickly learn and remember specific plant(s) and the locations where they ate those plant(s). We provide examples of AIA, synthesized by over 200 plant species in 16 families, which affect learning and memory in mammals. Using 36 examples of acetylcholinesterase inhibitors synthesized by plants in 58 families, we also show that acetylcholinesterase blockers contribute to anti‐herbivore chemical defense by affecting food‐aversion learning and memory in mammalian herbivores. We provide an evolutionary rationale for why natural selection may favor synthesis of chemicals that positively affect mental functions of herbivores. Our hypothesis, which challenges the current view that plant chemical defenses are aimed solely at destabilizing herbivore physiology, facilitates a broader understanding of diet preferences and feeding behavior in mammalian herbivores

The Collection of Egyptian Mummies of the University of Warsaw and their Role in the ‘Prehistory’ of Polish Egyptology

The University of Warsaw has a collection of ancient Egyptian objects, including four human mummies (200334 MNW, 236805/3 MNW, 236806 MNW, along with the mummy remains under two numbers KMS St. 0089 and KMS St. 0096 from the coffin 236804 MNW). They were donated by various persons in the nineteenth century. This paper establishes their dating, history, provenances, and research history in the context of the university’s antiquities collection, interests in ancient Egypt, and the development of Egyptology in Poland, especially in Warsaw. Previous studies on the subject were problematic owing to the limited and dispersed nature of sources and the fact that some of them were ambiguous and sometimes contradictory. Since then, more information has become available, especially computed tomography and X-ray scans of the mummies made by the Warsaw Mummy Project in cooperation with the National Museum in Warsaw. This has allowed further elaboration on the history of the collection and to re-establish identities of some of the deceased.The University of Warsaw has a collection of ancient Egyptian objects, including four human mummies (200334 MNW, 236805/3 MNW, 236806 MNW, along with the mummy remains under two numbers KMS St. 0089 and KMS St. 0096 from the coffin 236804 MNW). They were donated by various persons in the nineteenth century. This paper establishes their dating, history, provenances, and research history in the context of the university’s antiquities collection, interests in ancient Egypt, and the development of Egyptology in Poland, especially in Warsaw. Previous studies on the subject were problematic owing to the limited and dispersed nature of sources and the fact that some of them were ambiguous and sometimes contradictory. Since then, more information has become available, especially computed tomography and X-ray scans of the mummies made by the Warsaw Mummy Project in cooperation with the National Museum in Warsaw. This has allowed further elaboration on the history of the collection and to re-establish identities of some of the deceased

Immunogenetic novelty confers a selective advantage in host–pathogen coevolution

The major histocompatibility complex (MHC) is crucial to the adaptive immune response of vertebrates and is among the most polymorphic gene families known. Its high diversity is usually attributed to selection imposed by fast-evolving pathogens. Pathogens are thought to evolve to escape recognition by common immune alleles, and, hence, novel MHC alleles, introduced through mutation, recombination, or gene flow, are predicted to give hosts superior resistance. Although this theoretical prediction underpins host–pathogen “Red Queen” coevolution, it has not been demonstrated in the context of natural MHC diversity. Here, we experimentally tested whether novel MHC variants (both alleles and functional “supertypes”) increased resistance of guppies (Poecilia reticulata) to a common ectoparasite (Gyrodactylus turnbulli). We used exposure-controlled infection trials with wild-sourced parasites, and Gyrodactylus-naïve host fish that were F2 descendants of crossed wild populations. Hosts carrying MHC variants (alleles or supertypes) that were new to a given parasite population experienced a 35–37% reduction in infection intensity, but the number of MHC variants carried by an individual, analogous to heterozygosity in single-locus systems, was not a significant predictor. Our results provide direct evidence of novel MHC variant advantage, confirming a fundamental mechanism underpinning the exceptional polymorphism of this gene family and highlighting the role of immunogenetic novelty in host–pathogen coevolution

MHC allele frequency distributions under parasite-driven selection: A simulation model

<p>Abstract</p> <p>Background</p> <p>The extreme polymorphism that is observed in major histocompatibility complex (MHC) genes, which code for proteins involved in recognition of non-self oligopeptides, is thought to result from a pressure exerted by parasites because parasite antigens are more likely to be recognized by MHC heterozygotes (heterozygote advantage) and/or by rare MHC alleles (negative frequency-dependent selection). The Ewens-Watterson test (EW) is often used to detect selection acting on MHC genes over the recent history of a population. EW is based on the expectation that allele frequencies under balancing selection should be more even than under neutrality. We used computer simulations to investigate whether this expectation holds for selection exerted by parasites on host MHC genes under conditions of heterozygote advantage and negative frequency-dependent selection acting either simultaneously or separately.</p> <p>Results</p> <p>In agreement with simple models of symmetrical overdominance, we found that heterozygote advantage acting alone in populations does, indeed, result in more even allele frequency distributions than expected under neutrality, and this is easily detectable by EW. However, under negative frequency-dependent selection, or under the joint action of negative frequency-dependent selection and heterozygote advantage, distributions of allele frequencies were less predictable: the majority of distributions were indistinguishable from neutral expectations, while the remaining runs resulted in either more even or more skewed distributions than under neutrality.</p> <p>Conclusions</p> <p>Our results indicate that, as long as negative frequency-dependent selection is an important force maintaining MHC variation, the EW test has limited utility in detecting selection acting on these genes.</p

The Topography of the Town of Pathyris in the Light of the Current Research

The town of Per-Hathor, also known under its Greek name Pathyris, was occupied since the Predynastic Period up to the medieval times. It is well known for its Ptolemaic papyri, ostraka, and inscribed wooden tablets, which enable scholars to attempt reconstructions of the topography and social life in the settlement. What the previous studies lacked were a detail spatial and archaeological data regarding this area. The Gebelein Archaeological Project was initiated in 2013 and one of its aims is to fulfill this void