27/4 Spring Bookssc
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Chromosomal Evolution in Raphicerus Antelope Suggests Divergent X
www.nature.com/scientificreports OPEN Chromosomal evolution in Raphicerus antelope suggests divergent X chromosomes may drive speciation through females, rather than males, contrary to Haldane’s rule Terence J. Robinson1*, Halina Cernohorska2, Svatava Kubickova2, Miluse Vozdova2, Petra Musilova2 & Aurora Ruiz‑Herrera3,4 Chromosome structural change has long been considered important in the evolution of post‑zygotic reproductive isolation. The premise that karyotypic variation can serve as a possible barrier to gene fow is founded on the expectation that heterozygotes for structurally distinct chromosomal forms would be partially sterile (negatively heterotic) or show reduced recombination. We report the outcome of a detailed comparative molecular cytogenetic study of three antelope species, genus Raphicerus, that have undergone a rapid radiation. The species are largely conserved with respect to their euchromatic regions but the X chromosomes, in marked contrast, show distinct patterns of heterochromatic amplifcation and localization of repeats that have occurred independently in each lineage. We argue a novel hypothesis that postulates that the expansion of heterochromatic blocks in the homogametic sex can, with certain conditions, contribute to post‑ zygotic isolation. i.e., female hybrid incompatibility, the converse of Haldane’s rule. This is based on the expectation that hybrids incur a selective disadvantage due to impaired meiosis resulting from the meiotic checkpoint network’s surveillance of the asymmetric expansions of heterochromatic blocks in the homogametic sex. Asynapsis of these heterochromatic regions would result in meiotic silencing of unsynapsed chromatin and, if this persists, germline apoptosis and female infertility. Te chromosomal speciation theory 1,2 also referred to as the “Hybrid dysfunction model”3, has been one of the most intriguing questions in biology for decades. -
Gabriel Dover)
Dear Mr Darwin (Gabriel Dover) Home | Intro | About | Feedback | Prev | Next | Search Steele: Lamarck's Was Signature Darwin Wrong? Molecular Drive: the Third Force in evolution Geneticist Gabriel Dover claims that there is a third force in evolution: 'Molecular Drive' beside natural selection and neutral drift. Molecular drive is operationally distinct from natural selection and neutral drift. According to Dover it explains biological phenomena, such as the 700 copies of a ribosomal RNA gene and the origin of the 173 legs of the centipede, which natural selection and neutral drift alone cannot explain. by Gert Korthof version 1.3 24 Mar 2001 Were Darwin and Mendel both wrong? Molecular Drive is, according to Dover, an important factor in evolution, because it shapes the genomes and forms of organisms. Therefore Neo-Darwinism is incomplete without Molecular Drive. It is no wonder that the spread of novel genes was ascribed to natural selection, because it was the only known process that could promote the spread of novel genes. Dover doesn't reject the existence of natural selection but points out cases where natural selection clearly fails as a mechanism. Molecular drive is a non-Darwinian mechanism because it is independent of selection. We certainly need forces in evolution, since natural selection itself is not a force. It is the passive outcome of other processes. It is not an active process, notwithstanding its name. Natural selection as an explanation is too powerful for its own good. Molecular drive is non-Mendelian because some DNA segments are multiplied disproportional. In Mendelian genetics genes are present in just two copies (one on the maternal and one on the paternal chromosome). -
Completed Thesis
THE UNIVERSITY OF WINCHESTER Faculty of Humanities and Social Sciences Human Uniqueness: Twenty-First Century Perspectives from Theology, Science and Archaeology Josephine Kiddle Bsc (Biology) MA (Religion) Thesis for the degree of Doctor of Philosophy February 2013 This Thesis has been completed as a requirement for a postgraduate research degree of the University of Winchester. The word count is: 89350 THE UNIVERSITY OF WINCHESTER ABSTRACT FOR THESIS Human Uniqueness: Twenty-First Century Perspectives from Theology, Science and Archaeology A project aiming to establish, through the three disciplines, the value of human uniqueness as an integrating factor for science with theology Josephine Kiddle Bsc (Biology) MA (Religion) Faculty of Humanities and Social Sciences Doctor of Philosophy February 2013 The theme that underlies the thesis is the challenge presented by science, as it developed from the time of the Enlightenment through the centuries until the present day, to Christian theology. The consequent conflict of ideas is traced in respect of biological science and the traditions of Protestant Christian doctrine, together with the advances of the developing discipline of prehistoric archaeology since the early nineteenth century. The common ground from which disagreement stemmed was the existence of human beings and the uniqueness of the human species as a group amongst all other creatures. With the conflict arising from this challenge, centring on the origin and history of human uniqueness, a rift became established between the disciplines which widened as they progressed through to the twentieth century. It is this separation that the thesis takes up and endeavours to analyse in the light of the influence of advancing science on the blending of philosophical scientific ideas with the elements of Christian faith of former centuries. -
Phylogenetic Systematics and the Evolutionary History of Some Intestinal Flatworm Parasites (Trematoda: Digenea: Plagiorchi01dea) of Anurans
PHYLOGENETIC SYSTEMATICS AND THE EVOLUTIONARY HISTORY OF SOME INTESTINAL FLATWORM PARASITES (TREMATODA: DIGENEA: PLAGIORCHI01DEA) OF ANURANS by RICHARD TERENCE 0'GRADY B.Sc, University Of British Columbia, 1978 M.Sc, McGill University, 1981 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE STUDIES Department Of Zoology We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA March 1987 © Richard Terence O'Grady, 1987 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the Head of my Department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of Zoology The University of British Columbia 2075 Wesbrook Place Vancouver, Canada V6T 1W5 Date: March 24, 1987 i i Abstract Historical structuralism is presented as a research program in evolutionary biology. It uses patterns of common ancestry as initial hypotheses in explaining evolutionary history. Such patterns, represented by phylogenetic trees, or cladograms, are postulates of persistent ancestral traits. These traits are evidence of historical constraints on evolutionary change. Patterns and processes consistent with a cladogram are considered to be consistent with an initial hypothesis of historical constraint. As an application of historical structuralism, a phylogenetic analysis is presented for members of the digenean plagiorchioid genera Glypthelmins Stafford, 1905 and Haplometrana Lucker, 1931. -
Molecular Evolution
SYSTEMATICS & EVOLUTION Molecular Evolution GINCY C GEORGE (Assistant Professor On Contract) Molecular Evolution Molecular Evolution • Molecular evolution is the area of evolutionary biology that studies evolutionary change at the level of the DNA sequence. Molecular Evolution • It includes the study of rates of sequence change, relative importance of adaptive and neutral changes, and changes in genome structure. Molecular evolution examines DNA and proteins, addressing two types of questions: How do DNA and proteins evolve? How are genes and organisms evolutionarily related? Study of how genes and proteins evolve and how are organisms related based on their DNA sequence • Molecular evolution therefore is the determination and comparative study of DNA and deduced amino acid sequences. • Sequences from different organisms or populations are matched or aligned • Evolution at molecular level is observable at the base (nucleotide) level changes in the DNA and amino acid changes in proteins • Both can be studied by examining the differences between species • Both polymorphism and evolutionary changes between species can be explained by two processes ie; • Natural selection and Neutral drift • The main factors that influence Natural selection and Neutral drift are population size and the selection coefficient of the different genotypes • If the population is small and the selection coefficient low; genetic drift dominates, • Whereas natural selection dominates if the population and selection coefficients are large • Evolution of Modern species -
Concerted Evolution at the Population Level: Pupfish Hindill Satellite DNA Sequences JOHN F
Proc. Nati. Acad. Sci. USA Vol. 91, pp. 994-998, February 1994 Evolution Concerted evolution at the population level: Pupfish HindIll satellite DNA sequences JOHN F. ELDER, JR.* AND BRUCE J. TURNER Department of Biology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 Communicated by Bruce Wallace, October 18, 1993 ABSTRACT The canonical monomers (170 bp) of an organisms. There are very little data on their variation within abundant (1.9 x 10' copies per diploid genome) satellite DNA or divergence among conspecific natural populations. sequence family In the genome of Cyprinodon wriegau, a We report here sequence comparisons ofthe predominant "pph" that ranges along the Atlantic coast fom Cape Cod or "canonical" monomers of a satellite DNA array in sam- to central Mexico, are divergent in base sequence in 10 of 12 ples of 12 natural populations of Cyprinodon variegatus smle collected from natural populations. The divergence (Cyprinodontidae), a coastal killifish species. Ten of these Involves sbsitions, deletis, and insertions, is marked in samples have distinctive and characteristic canonical mono- scoe (mean pairwise sequence slarit = 61.6%; range = mers with high levels of intraindividual and intrapopulation 35-95.9%), Is largely ed to the 3' half of the monomer, homogeneity.t In other words, this satellite DNA has appar- and Is not correlated with the disace among cllg sites. ently undergone concerted evolution at or near the level of Repetitive loning and direct genomic sequencing expriments the local population. failed to detect intrapopulation and intraindividual variation, A preliminary account of some of our early findings has hig levels of sequence homogeneity within popu- appeared in a symposium volume (6). -
The Role of Causal Processes in the Neutral and Nearly Neutral Theories
Dartmouth College Dartmouth Digital Commons Dartmouth Scholarship Faculty Work 12-2008 The Role of Causal Processes in the Neutral and Nearly Neutral Theories Michael R. Dietrich Dartmouth College Roberta L. Millstein University of California, Davis Follow this and additional works at: https://digitalcommons.dartmouth.edu/facoa Part of the Biology Commons, Evolution Commons, and the Philosophy of Science Commons Dartmouth Digital Commons Citation Dietrich, Michael R. and Millstein, Roberta L., "The Role of Causal Processes in the Neutral and Nearly Neutral Theories" (2008). Dartmouth Scholarship. 1906. https://digitalcommons.dartmouth.edu/facoa/1906 This Article is brought to you for free and open access by the Faculty Work at Dartmouth Digital Commons. It has been accepted for inclusion in Dartmouth Scholarship by an authorized administrator of Dartmouth Digital Commons. For more information, please contact [email protected]. The Role of Causal Processes in the Neutral and Nearly Neutral Theories Michael R. Dietrich and Roberta L. Millstein† The neutral and nearly neutral theories of molecular evolution are sometimes char- acterized as theories about drift alone, where drift is described solely as an outcome, rather than a process. We argue, however, that both selection and drift, as causal processes, are integral parts of both theories. However, the nearly neutral theory ex- plicitly recognizes alleles and/or molecular substitutions that, while engaging in weakly selected causal processes, exhibit outcomes thought to be characteristic of random drift. A narrow focus on outcomes obscures the significant role of weakly selected causal processes in the nearly neutral theory. 1. Introduction. Gabriel Dover once complained that being nearly neutral is like being “just a little bit pregnant” (Dover 1997, 91). -
Molecular Facts and Evolutionary Theory
Journal and Proceedings of The Royal Society of New South Wales Volume 120 Parts 1 and 2 [Issued September, 1987] pp.39-48 Return to CONTENTS Molecular Facts and Evolutionary Theory George L. Gabor Miklos Evolutionary biology has had a fascinating recent history. It was realized more than a century ago that the way of approaching many evolutionary problems lay in studies of morphology. However, as pointed out by Bateson in 1922, “discussions of evolution came to an end primarily because no progress was being made. Morphology having been explored in the minutest corners, we turned elsewhere. We became geneticists in the conviction that there at least must evolutionary wisdom be found.” At the same time, while it was clear that morphology must have its bases in embryology, it was instead the mathematically oriented theory of neo-Darwinism that rose to prominence over the next half century. This theory is essentially an amalgam of Mendelian genetics and classical Darwinian selection, firmly based on changes in gene frequencies at particular loci. In the late 1960s, it began to be evaluated at a crude molecular level using gel electrophoresis techniques that allowed the examination of polymorphisms at many enzyme coding loci. In the mid 1970s the technological advances of genetic engineering ushered in an entirely new era of molecular biology. The molecular biologist became the successor to the pure geneticist, and the focus switched back to the molecular analysis of development. The molecular biology of recombinant DNA revolutionized the previous concepts of genome organization and function and led to a reappraisal of the importance of neo-Darwinism. -
Abstracts of Papers Presented at the Mammalian Genetics Group
Genet. Res., Camb. (1982), 40, pp. 99-106 gg Printed in Great Britain Abstracts of papers presented at the Mammalian Genetics Group meeting, held at the Royal Free Hospital Medical School on 26 and 27 November 1981 Are patterns of cell differentiation reflected in mammalian gene maps? BY LARS-G. LUNDIN Department of Medical and Physiological Chemistry, Biomedicum, University of Uppsala, Box 575 S-751 23, Uppsala, Sweden There are two separate types of gene homologies. New genetic material can arise by gene duplication, either by regional duplication or by tetraploidization. Both these mechanisms of gene duplication give rise to paralogous genes through subsequent divergent evolution. Thus, paralogous genes exist within a species and have a common ancestral gene. Orthologous genes are found in different species and have diverged from their common ancestral gene as part of the process of speciation and separate evolution. Linkage conservation, as reflected by orthologous chromo- somal regions, has been demonstrated for quite extensive parts of mammalian chromosomes. Three possible groups of paralogous chromosomal regions in mouse and man will be suggested. The phenomenon of differential gene silencing and its consequence for our ability to detect paralogies will be described and exemplified. It is suggested that there may be a temporal relationship between closely linked genes. This will be exemplified by genes likely to be active in cells derived from the neural crest. Thus, it seems that genes for inner ear defects in the mouse are often closely linked to coat colour genes. Some other genes clustering around pigment genes will be discussed. Comparative aspects of the evolution of 'dispersed' and 'tandem' families of sequences in species of rodents BY GABRIEL DOVER AND S. -
Genetic Determinism As Evolutionary Psychology
The Emperor Still Has No Clothes! Genetic Determinism as Evolutionary Psychology. Melanie Lazarow. Hilary Rose and Stephen Rose (eds.), Alas Poor Darwin: Arguments Against Evolutionary Psychology. London: Vintage, 2001; Richard C. Lewontin, It Ain't Necessarily So: The Dream of the Human Genome and Other Illusions. New York: New York Review of Books, 2000. Alas Poor Darwin and It Ain't Necessarily So are excellent tools to help dispel some of the commonly-promoted ideas about genetic determinism that have become so widespread in both academic and popular writing. Evolutionary psychology (EP) has precursors in both sociobiology and eugenics, yet differs from them, pointedly in that sociobiology was never seriously academically accepted while EP is part of the mainstream of academic programs in psychology, biology and anthropology. However it still serves the important ideological purpose of reinforcing sexism, racism and inequality today. EP is needed because, after all, in a society of equal opportunity and social mobility, how is one to explain differences in social power if not by differences in intrinsic ability? Both books show how genetic determinism - although it is poor science - proclaims itself as the legitimate emperor of twenty-first century psychology. PsycInfo, the major psychological database for psychology literature, shows a dramatic increase in the number of articles on EP in the last 15 years. A search in its three component databases shows that between 1887-1966 there were 5 articles on EP; 1967-1983, 8 articles; but 1984-present, 371 articles. Against this tide, these books take on the necessary task of both defending evolution and opposing neo-Darwinism. -
Stephen Jay Gould Papers M1437
http://oac.cdlib.org/findaid/ark:/13030/kt229036tr No online items Guide to the Stephen Jay Gould Papers M1437 Jenny Johnson Department of Special Collections and University Archives August 2011 ; revised 2019 Green Library 557 Escondido Mall Stanford 94305-6064 [email protected] URL: http://library.stanford.edu/spc Guide to the Stephen Jay Gould M1437 1 Papers M1437 Language of Material: English Contributing Institution: Department of Special Collections and University Archives Title: Stephen Jay Gould papers creator: Gould, Stephen Jay source: Shearer, Rhonda Roland Identifier/Call Number: M1437 Physical Description: 575 Linear Feet(958 boxes) Physical Description: 1180 computer file(s)(52 megabytes) Date (inclusive): 1868-2004 Date (bulk): bulk Abstract: This collection documents the life of noted American paleontologist, evolutionary biologist, and historian of science, Stephen Jay Gould. The papers include correspondence, juvenilia, manuscripts, subject files, teaching files, photographs, audiovisual materials, and personal and biographical materials created and compiled by Gould. Both textual and born-digital materials are represented in the collection. Preferred Citation [identification of item], Stephen Jay Gould Papers, M1437. Dept. of Special Collections, Stanford University Libraries, Stanford, Calif. Publication Rights While Special Collections is the owner of the physical and digital items, permission to examine collection materials is not an authorization to publish. These materials are made available for use -
Adaptive Protein Evolution in Animals and the Effective Population Size Hypothesis Nicolas Galtier
Adaptive Protein Evolution in Animals and the Effective Population Size Hypothesis Nicolas Galtier To cite this version: Nicolas Galtier. Adaptive Protein Evolution in Animals and the Effective Population Size Hypothesis. PLoS Genetics, Public Library of Science, 2016, 12 (1), 10.1371/journal.pgen.1005774. hal-01900669 HAL Id: hal-01900669 https://hal.archives-ouvertes.fr/hal-01900669 Submitted on 22 Oct 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. RESEARCH ARTICLE Adaptive Protein Evolution in Animals and the Effective Population Size Hypothesis Nicolas Galtier* Institut des Sciences de l'Evolution UMR5554, Université Montpellier–CNRS–IRD–EPHE, Montpellier, France * [email protected] Abstract The rate at which genomes adapt to environmental changes and the prevalence of adaptive processes in molecular evolution are two controversial issues in current evolutionary genet- ics. Previous attempts to quantify the genome-wide rate of adaptation through amino-acid substitution have revealed a surprising diversity of patterns, with some species (e.g. Dro- sophila) experiencing a very high adaptive rate, while other (e.g. humans) are dominated by nearly-neutral processes. It has been suggested that this discrepancy reflects between- OPEN ACCESS species differences in effective population size.