1Mobile CommunicationSystem Evolution1.1 Historical PerspectiveThe mobile phone has proved to be one of the most outstanding technological and commer-cial successes of the last decade. Since its introduction in the 1980s, the phone’s place in themarket place has rapidly progressed from a minority, specialised item to virtually an essentialcommodity for both business and leisure use. Over the last two decades, advances in mobiletechnology, combined with the significant reduction in operating costs and the developmentof new applications and services, have ensured a buoyant market. By mid-2000, there wereover 220 million mobile subscribers in Europe and over 580 million mobile subscribersworld-wide. In the UK, every other person owns a mobile phone; while in Finland the numberof mobile phones per capita now exceeds that of households with fixed phone lines.As with most technological innovations, the mobile phone’s marketability is not based onovernight success but rather a systematic, evolutionary development involving multi-nationalco-operation at both technical and political levels. In fact, the concept of a mobile phone isnot new. As early as 1947, the cellular concept was discussed within Bell Laboratories [YOU-79]. However, it was not until the 1970s that technology had developed sufficiently to allowthe commercial implementation of such a system to be investigated.The evolution of mobile communications can be categorised into generations of develop-ment. Presently, we are on the verge of the third-generation (3G) of mobile systems. Broadlyspeaking, first-generation (1G) systems are those that paved the way and are generallycategorised as being national networks that are based on analogue technology. Such networkswere introduced into service in the 1980s. These networks were designed to provide voicecommunications to the mobile user.Second-generation (2G) systems are categorised by digital technology. They are supportedby international roaming agreements, allowing the possibility to operate a mobile phone acrossnational boundaries. With the introduction of 2G systems, in addition to digital voice tele-phony, a new range of low data rate digital services became available, including mobile fax,voice mail and short message service (SMS) [PEE-00]. Also at this stage in the evolution, newtypes of systems began to emerge which catered for particular market needs; not only cellularmobile, but also cordless, public mobile radio, satellite and wireless-local area network (W-LAN) solutions. 2G systems are synonymous with the globalisation of mobile systems, and inMobile Satellite Communication Networks. Ray E. Sheriff and Y. Fun HuCopyright q 2001 John Wiley & Sons LtdISBNs: 0-471-72047-X (Hardback); 0-470-845562 (Electronic) this respect the importance of standardisation is clear. For example, GSM, which was standar-dised in Europe by the European Telecommunications Standards Institute (ETSI), is nowrecognised as a global standard, with its adoption in most countries of the world. The finalevolutionary phase of 2G networks, in recognition of the importance of the Internet and as astepping stone towards the introduction of 3G technology, introduced packet-oriented services,providing the first opportunity to introduce mobile-multimedia services.Within the next few years, it is expected that mobile users will wish to access broadbandmultimedia services, such as those provided by fixed networks. This demand for broaderbandwidth services is driven by the need to provide services and applications comparablewith those presently available to personal computers (PCs). The phenomenal growth in theInternet, with over 500 million users predicted by 2005, Population Evolution Population Evolution Bởi: OpenStaxCollege The mechanisms of inheritance, or genetics, were not understood at the time Charles Darwin and Alfred Russel Wallace were developing their idea of natural selection This lack of understanding was a stumbling block to understanding many aspects of evolution In fact, the predominant (and incorrect) genetic theory of the time, blending inheritance, made it difficult to understand how natural selection might operate Darwin and Wallace were unaware of the genetics work by Austrian monk Gregor Mendel, which was published in 1866, not long after publication of Darwin's book, On the Origin of Species Mendel’s work was rediscovered in the early twentieth century at which time geneticists were rapidly coming to an understanding of the basics of inheritance Initially, the newly discovered particulate nature of genes made it difficult for biologists to understand how gradual evolution could occur But over the next few decades genetics and evolution were integrated in what became known as the modern synthesis—the coherent understanding of the relationship between natural selection and genetics that took shape by the 1940s and is generally accepted today In sum, the modern synthesis describes how evolutionary processes, such as natural selection, can affect a population’s genetic makeup, and, in turn, how this can result in the gradual evolution of populations and species The theory also connects this change of a population over time, called microevolution, with the processes that gave rise to new species and higher taxonomic groups with widely divergent characters, called macroevolution Everyday Connection Evolution and Flu VaccinesEvery fall, the media starts reporting on flu vaccinations and potential outbreaks Scientists, health experts, and institutions determine recommendations for different parts of the population, predict optimal production and inoculation schedules, create vaccines, and set up clinics to provide inoculations You may think of the annual flu shot as a lot of media hype, an important health protection, or just a briefly uncomfortable prick in your arm But you think of it in terms of evolution? The media hype of annual flu shots is scientifically grounded in our understanding of evolution Each year, scientists across the globe strive to predict the flu strains that they anticipate being most widespread and harmful in the coming year This knowledge is 1/7 Population Evolution based in how flu strains have evolved over time and over the past few flu seasons Scientists then work to create the most effective vaccine to combat those selected strains Hundreds of millions of doses are produced in a short period in order to provide vaccinations to key populations at the optimal time Because viruses, like the flu, evolve very quickly (especially in evolutionary time), this poses quite a challenge Viruses mutate and replicate at a fast rate, so the vaccine developed to protect against last year’s flu strain may not provide the protection needed against the coming year’s strain Evolution of these viruses means continued adaptions to ensure survival, including adaptations to survive previous vaccines Population Genetics Recall that a gene for a particular character may have several alleles, or variants, that code for different traits associated with that character For example, in the ABO blood type system in humans, three alleles determine the particular blood-type protein on the surface of red blood cells Each individual in a population of diploid organisms can only carry two alleles for a particular gene, but more than two may be present in the individuals that make up the population Mendel followed alleles as they were inherited from parent to offspring In the early twentieth century, biologists in a field of study known as population genetics began to study how selective forces change a population through changes in allele and genotypic frequencies The allele frequency (or gene frequency) is the rate at which a specific allele appears within a population Until now we have discussed evolution as a change in the characteristics of a population of organisms, but behind that phenotypic change is genetic change In population genetics, the term evolution is defined as a change in the frequency of an allele in a population Using the ABO blood type system as an example, the frequency of one of the alleles, IA, is the number of copies of that allele divided by all the copies of the ABO gene in the population For example, a study in Jordan Sahar S Hanania, Dhia S Hassawi, and Nidal M Irshaid, “Allele Frequency and Molecular Genotypes of ABO Blood Group System in a Jordanian Population,” Journal of Medical Sciences (2007): 51-58, doi:10.3923/jms.2007.51.58 found a frequency of IA to be 26.1 percent The IB and I0 alleles made up 13.4 percent and 60.5 percent of the alleles respectively, and all of the frequencies added up to 100 percent A change in this ...molecular population genetics and evolution Go to MENU MOLECULAR I'OPULATION GENETICS AND EVOLUTION NORTH - HOLLAND RESEARCH MONOGRAPHS FRONTIERS OF BIOLOGY VOLUME 40 Under the General Editorship of A. NEUBERGER London and E. L. TATUM New York NORTH - HOLLAND PUBLISHING COMPANY AMSTERDAM . OXFORD MOLECULAR POPULATION GENETICS AND EVOLUTION MASATOSHI NEI Center for Denlogruphic and Population Genetics University of Texas at Houstort NORTH - HOLLAND PUBLISHING COMPANY, AMSTERDAM OXFORD AMERICAN ELSEVIER PUBLISHING COMPANY, INC. - NEW YORK @ North-Hollmd Publishing Company - 1975 AN rights reserved. No part of this prlblication may be reproduced, stored in a retrieval systeni, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior perrnission of the copyright owner. Library of Congress Catalog Card Number: 74 - 84734 North-Hollanrl ISBN for this series: 0 7204 7100 1 North-Hollancl ISBN for this volume: 0 7204 7141 9 American Elsevier ISBN: 0444 10751 7 PUBLISHERS: NORTH - HOLLAND PUBLISHING COMPANY - AMSTERDAM NORTH - HOLLAND PUBLISHING COMPANY LTD. - OXFORD SOLE DISTRIBUTORS FOR TI - IE U.S.A. AND CANADA: AMERICAN ELSEVIER PUBLISHING COMPANY, INC. 52 VANDERBILT AVENUE, NEW YORK, N.Y. 10017 PRINTED IN TllE NETHERLANDS Go to CONTENTS General preface The aim of the publication of this series of monographs, known under the collective title of 'Frontiers of Biology', is to present coherent and up - to - date views of the fundamental concepts which dominate modern biology. Biology in its widest sense has made very great advances during the past decade, and the rate of progress has been steadily accelerating. Undoubtedly important factors in this acceleration have been the effective use by biologists of new techniques, including electron microscopy, isotopic labels, and a great variety of physical and chemical techniques, especially those with varying degrees of automation. In addition, scientists with partly physical or chemical backgrounds have become interested in the great variety of prob - lems presented by living organisms. Most significant, however, increasing interest in and understanding of the biology of the cell, especially in regard to the molecular events involved in genetic phenomena and in metabolism and its control, have led to the recognition of patterns common to all forms of life from bacteria to man. These factors and unifying concepts have led to a situation in which the sharp boundaries between the various classical biological disciplines are rapidly disappearing. Thus, while scientists are becoming increasingly specialized in their techniques, to an increasing extent they need an intellectual and conceptual approach on a wide and non-specialized basis. It is with these considerations and needs in mind that this series of monographs, 'Frontiers of Biology' has been conceived. The advances in various areas of biology, including microbiology, biochemistry, genetics, cytology, and cell structure and function in general will be presented by authors who have themselves contributed significantly to these developments. They will have, in this series, the opportunity of bringing together, from diverse sources, theories and experimental data, and of integrating these into a more general conceptual framework. It is Go to CONTENTS VI General preface unavoidable, and probably even desirable, that the special bias of the indi - vidual authors will become For the past few decades, advances in molecular biology have continuously refined our understanding of human evolutionary history. A simple model of expansion and global migrations from a single ancestral human popu- lation with adaptation at a few protein polymor phisms has transformed into a complex scenario involving introgression among numerous divergent groups, multiple population-specific bottlenecks, and thousands of candidate genomic sites of possible evolutionary importance [1-6]. Although the broad patterns of demographic trends, geographic population structure, and adaptation have now been well established [1-4], emerging genome-scale datasets will enable detailed inferences about particular populations and genes. Major ongoing goals include inferring intracontinental patterns of migration and admixture, reconstructing the history of human population growth and bottlenecks, and categorizing whether polymorphisms are selectively neutral, deleterious, or adaptive (Box 1). Until recently, such questions could be addressed only with the limited statistical power and precision afforded by single nucleotide polymorphism (SNP) arrays or small sets of sequence data. However, exome sequencing has the potential to address many of these questions. Exome sequencing is a new and powerful technique in which genomic DNA that binds to a predefined target of known exons is sequenced using next-generation technology, in order to capture the protein-coding Abstract Exome sequencing is poised to yield substantial insights into human genetic variation and evolutionary history, but there are signicant challenges to overcome before this becomes a reality. © 2010 BioMed Central Ltd The promise and limitations of population exomics for human evolution studies Jacob A Tennessen 1 , Timothy D O’Connor 1 , Michael J Bamshad 1,2 and Joshua M Akey 1 * O P IN I ON *Correspondence: akeyj@uw.edu 1 Department of Genome Sciences, University of Washington, 3720 15th Ave NE, Box 355065, Seattle, WA 98195-5065, USA Full list of author information is available at the end of the article Box 1. Goals and methods of population genetics Extant patterns of human genetic variation provide information about our demographic and evolutionary history. The goals of population genetics are to infer past events from DNA sequence variation and identify and quantify how evolutionary processes, such as natural selection, population structure, migration, genetic drift, and changes in population size, have shaped human genomic diversity. To this end, numerous population genetics statistics have been developed for analyzing genetic variation. A brief synopsis of population genetic statistics well suited to exome data is as follows. π: The expected number of dierences between two sequences randomly selected from the same locus in a population is represented as π. If π is calculated per base pair, data on both variable and invariant sites, and therefore sequence data rather than SNP array data, are required. Numerous evolutionary inferences rely on π. Its overall magnitude reects the mutation rate and eective size of a population. Unusually high or low π at a locus can be a signature of natural selection. Most genes in most human populations have per base π values between 10 -4 and 10 -3 [13]. Site frequency spectra: A site frequency spectrum represents the relative numbers of variants occurring at all frequencies in a population. The proportion of rare variants as compared with common variants can be used to infer the rate and timing of population growth. Unique spectra for certain genes or certain site classes are thought to reect variation in the strength and form of natural selection. For example, a selective sweep may eliminate all variation, and all new variants arising after the sweep will be rare initially, resulting in a skewed spectrum with a relative dearth of common variants. Tajima’s D is a summary RESEARC H Open Access Evolution of Dengue Virus Type 3 Genotype III in Venezuela: Diversification, Rates and Population Dynamics Alvaro Ramírez 1† , Alvaro Fajardo 2† , Zoila Moros 1 , Marlene Gerder 1 , Gerson Caraballo 1 , Daria Camacho 3 , Guillermo Comach 3 , Victor Alarcón 4 , Julio Zambrano 4 , Rosa Hernández 4 , Gonzalo Moratorio 2 , Juan Cristina 2* , Ferdinando Liprandi 1 Abstract Background: Dengue virus (DENV) is a member of the gen us Flavivirus of the family Flaviviridae. DENV are comprised of four distinct serotypes (DENV-1 through DENV-4) and each serotype can be divided in different genotypes. Currently, there is a dramatic emergence of DENV-3 genotype III in Latin America. Nevertheless, we still have an incomplete understanding of the evolutionary forces underlying the evolution of this genotype in this region of the world. In order to gain insight into the degree of genetic variability, rates and patterns of evolution of this genotype in Venezuela and the South American region, phylogenetic analysis, based on a large number (n = 119) of envelope gene sequences from DENV-3 genotype III strains isolated in Venezuela from 2001 to 2008, were performed. Results: Phylogenetic analysis revealed an in situ evolution of DENV-3 genotype III following its introduction in the Latin American region, where three different genetic clusters (A to C) can be observed among the DENV-3 genotype III strains circulating in this region. Bayesian coalescent inference analyses revealed an evolutionary rate of 8.48 × 10 -4 substitutions/site/year (s/s/y) for strains of cluster A, composed entirely of strains isolated in Venezuela. Amino acid substitution at position 329 of domain III of the E protein (A®V) was found in almost all E proteins from Cluster A strains. Conclusions: A significant evolutionary change between DENV-3 genotype III strains that circulated in the initial years of the introduction in the continent and strains isolated in the Latin American region in recent years was observed. The presence of DENV-3 genotype III strains belonging to different clusters was observed in Venezuela, revealing several introduction events into this country. The evolutionary rate found for Cluster A strains circulating in Venezuela is similar to the others previously established for this genotype in other regions of the world. This suggests a lack of correlation among DENV genotype III substitution rate and ecological pattern of virus spread. Background Dengue virus (DENV) is a member of the genus Flavi- virus of the family Flaviviridae. DENV are mosquito-borne flaviviruses with a single- stranded, nonsegmented, positive-sense RNA genome of approximately 11 kb in le ngth [1]. Dengue viruses are comprised of four distinct sero types (DENV-1 through DENV-4), which are transmitted to humans through the bites of two mosquito species: Aedes aegypti and Aedes albopictus [2]. DENV causes a wide range of diseases in humans, from the acute febrile illness dengue fever (DF) to life- threatening dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). Dengue has spread throughout tropical and subtropical r egions worldwide over the past several decades, with an estimated 100 million infections and tens of millions of cases occurring annually [3]. Currently, there is a dramatic re-emergence of DENV in * Correspondence: cristina@cin.edu.uy † Contributed equally 2 Laboratorio de Virología Molecular. Centro de Investigaciones Nucleares. Facultad de Ciencias, Igua 4225, 11400 Montevideo, Uruguay Full list of author information is available at the end of the article Ramírez et al. Virology Journal 2010, 7:329 http://www.virologyj.com/content/7/1/329 © 2010 Ramírez et al; licensee BioMed Central Ltd. This is an Open Ac cess article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is BioMed Central Page 1 of 21 (page number not for citation purposes) Comparative Hepatology Open Access Review Eggshell and egg yolk proteins in fish: hepatic proteins for the next generation: oogenetic, population, and evolutionary implications of endocrine disruption Augustine Arukwe* 1 and Anders Goksøyr 2,3 Address: 1 Great Lakes Institute for Environmental Research, University of Windsor, Ontario, 401 Sunset Avenue, Windsor, N9B 3P4, Canada, 2 Biosense Laboratories AS, Thormøhlensgt. 55, N-5008, Bergen, Norway and 3 Department of Molecular Biology, University of Bergen, N-5020 Bergen, Norway Email: Augustine Arukwe* - arukwe@uwindsor.ca; Anders Goksøyr - anders@biosense.no * Corresponding author Abstract The oocyte is the starting point for a new generation. Most of the machinery for DNA and protein synthesis needed for the developing embryo is made autonomously by the fertilized oocyte. However, in fish and in many other oviparous vertebrates, the major constituents of the egg, i.e. yolk and eggshell proteins, are synthesized in the liver and transported to the oocyte for uptake. Vitellogenesis, the process of yolk protein (vitellogenin) synthesis, transport, and uptake into the oocyte, and zonagenesis, the synthesis of eggshell zona radiata proteins, their transport and deposition by the maturing oocyte, are important aspects of oogenesis. The many molecular events involved in these processes require tight, coordinated regulation that is under strict endocrine control, with the female sex steroid hormone estradiol-17β in a central role. The ability of many synthetic chemical compounds to mimic this estrogen can lead to unscheduled hepatic synthesis of vitellogenin and zona radiata proteins, with potentially detrimental effects to the adult, the egg, the developing embryo and, hence, to the recruitment to the fish population. This has led to the development of specific and sensitive assays for these proteins in fish, and the application of vitellogenin and zona radiata proteins as informative biomarkers for endocrine disrupting effects of chemicals and effluents using fish as test organisms. The genes encoding these important reproductive proteins are conserved in the animal kingdom and are products of several hundred million years of evolution. Introduction Teleost fish comprise more than 21,000 species, the larg- est group of vertebrates, inhabiting a wide variety of ma- rine and freshwater environments from the abysses of the deep sea to high mountain lakes. Through more than 200 million years of evolution, this group has adapted to their habitats by adopting a diverse array of reproductive strat- egies [1]. A common principle for all fish, however, is the production of large yolky eggs through the development of the oocyte. The formation, development and matura- tion of the female gamete and ovum (oogenesis) are intri- cate processes that require hormonal co-ordination. Oocyte growth is normally divided into four main stages, primary growth, formation of cortical alveoli, the vitello- genic period, and final maturation [2]. Oocytes are female ovarian cells that go through meiosis to become eggs. They are derived from oogonia, mitotic cells that develop from primordial germ cells migrating into the ovary early in embryogenesis [3]. In teleost fishes, Published: 6 March 2003 Comparative Hepatology 2003, 2:4 Received: 14 November 2002 Accepted: 6 March 2003 This article is available from: http://www.comparative-hepatology.com/content/2/1/4 © 2003 Arukwe and Goksøyr; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permit- ted in all media for any purpose, provided this notice is preserved along with the article's original URL. Comparative Hepatology 2003, 2 http://www.comparative-hepatology.com/content/2/1/4 Page 2 of 21 (page number not for citation purposes) full-grown postvitellogenic oocytes in the ovary are phys- iologically arrested at ... macroevolution? Microevolution describes the evolution of small organisms, such as insects, while macroevolution describes the evolution of large organisms, like people and elephants Microevolution... the evolution of microscopic entities, such as molecules and proteins, while macroevolution describes the evolution of whole organisms Microevolution describes the evolution of organisms in populations,... macroevolution describes the evolution of species over long periods of time Microevolution describes the evolution of organisms over their lifetimes, while macroevolution describes the evolution