DOCSLIB.ORG

Race Does Not Equal

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Race Does Not Equal RACE DNA IF RACE IS A SOCIAL CONSTRUCT, WHAT’S UP WITH DNA ANCESTRY TESTING? BY JOSEPH L. GRAVES ILLUSTRATION BY KEN ORVIDAS THE CONCEPT OF RACE is the elephant hold positive views of the police, only 52 make it sound like we’re examining the in the collective American living room. percent of African-American individu- elephant while blindfolded. Some of us It a!ects how we think about virtually als and 51 percent of Mexican-American describe the trunk, while others the tail every aspect of our society and cul- individuals share that view. In addition, and still others the feet. Our descrip- ture—and yet we struggle to talk about when asked the question of whether the tions and definitions are di!erent, and or even define it. police use lethal force only when neces- without understanding how they fit Numerous studies demonstrate sary, 59 percent, 16 percent and 23 per- together, we cannot ascertain a com- that members of socially defined racial cent of European-American, African- plete picture of the elephant. groups in the United States experi- American and Mexican-American indi- To speak meaningfully about race, ence the realities of life di!erently. For viduals respectively responded in the we need to truly understand how dif- example, a recent public opinion sur- a"rmative. ferent people perceive and define it and vey showed that while 80 percent of Often, when we try to describe the how these definitions fit together. This European-American (white) individuals elephant in the room, our attempts includes understanding socially defined !"!TEACHING TOLERANCE SUMMER !"#$%!" race, biological race, human variation gene flow among its major population wherever malaria is found, including and ancestry. Unfortunately, most centers (or regional clusters of inhabi- West Africa, the Arabian Peninsula, Americans do not, with the result that tants). Indeed, all modern humans liv- the Mediterranean Basin and in India. many racist beliefs are passed along ing today are descended from people It is not found among Kenyans whose as scientific fact. Have you ever heard who once lived in East Africa. (The old- ancestry is from high-altitude regions the stereotype “African Americans are est modern human fossils come from of that country. Therefore the sickle lazy”? Someone who understood how Omo Kibish in Ethiopia.) Humans did cell gene can’t be used to define races. human behavioral variation relates to not begin to populate the rest of the Another relevant example is skin socially defined race would know this world until about 60,000 years ago. color. Skin color variation is associ- statement is not logically possible—and Some of the first recorded civilizations ated with solar intensity, and thus all yet it has been used for centuries as one were located in Ethiopia (prior to 3,000 populations with tropical ancestry have of a number of scientifically impossi- B.C.E.) and then moved up the Blue Nile darker skin than those whose recent ble justifications for the subjugation to modern-day Egypt. Thus many of the ancestry is from the temperate and arc- of African-American individuals. biological traits not found in sub-Saha- tic zones. Solomon Islanders, for exam- ran Africans are relatively new; fair skin ple, have physical traits very similar to Taking O! the Blindfolds and the blue-eye allele are—at most— sub-Saharan Africans, yet these Pacific The majority of Americans still operate 6,000 years old. Finally this also means Islanders are much further apart on on the assumption that there are legiti- that when most people think of biolog- overall gene frequency (the percentage mate biological races within the human ical ancestry, they are really envision- of genes of a given type) from sub-Sa- species, and that these racial categories ing recent ancestry relative to our spe- haran Africans than from Europeans. align with physical features—in other cies’ existence (within the last 50,000 A less visible evolutionary trait is the words, the way that race is socially years or so). ability to tolerate milk beyond the defined in the United States. To debunk This is where our understanding age of weaning, which evolved both in this misconception, it is important to often gets fouled up. How is it possible Europeans and in some Africans (Masai understand two often-conflated defi- that geographically based genetic and tribe) due to the domestication of cat- nitions of race. physical variation can tell you some- tle. It stands to follow that if we attempt k BIOLOGICAL RACE has been thing about an individual’s recent bio- to infer relatedness between human defined by combinations of physical logical ancestry, and yet that variation groups based only on physical traits features, geographic ancestry, frequen- is not useful in identifying an individ- like dark skin and milk tolerance, we cies of genes (alleles) and evolutionary ual’s biological race? Isn’t it true that consistently incorrectly assign groups lineages. Biological races exist within Norwegians have fair complexions and of people together. some species. This is why we know they Nigerians are dark? Physical factors fail to correctly clus- do not exist within our species, modern It is true that all modern human ter humans and thus cannot be used to humans. populations have genetic di!erences assign people to racial groups—a fact k SOCIALLY DEFINED RACE has been that reflect adaptation to the environ- scientists have known since the 1940s! defined by an arbitrarily organized ments their “recent” ancestors inhab- Yet today, most Americans still combination of physical traits, geo- ited. There are also genetic changes utilize physical features to judge the graphic ancestry, language, religion that resulted from simple chance racial alignment of individuals. This and a variety of other cultural features. events. Have you ever heard the term mistake is understandable in the con- Social definitions of race di!er depend- “genetic drift”? This refers to chance text of American history, since physi- ing on context and always operate in the events that alter gene frequencies in cal features were a reliable indicator service of social-dominance hierarchies. populations. This happened when of ancestry for much of the nation’s The modern consensus of evolu- human groups migrated out of Africa history. Western Europeans (mainly tionary biologists is that our species at different times and in different from England) founded this coun- does not have enough genetic variabil- directions. Members of a given group try. They invaded the territory of the ity among its populations to justify carried a unique subset of all human American Indians (whose recent bio- either the identification of geograph- genetic variation with them. For all logical descent was from Central ically based races or of evolutionarily these reasons, there is no single phys- and Northeast Asia), and then cap- distinct lineages. This is because we are ical trait or gene that can be used to tured, transported and enslaved peo- a relatively young species (150,000– unambiguously assign people to racial ple from West and Central Africa. 200,000 years old) that has always groups. Here’s an example: The sickle This meant that the original inhabi- maintained significant amounts of cell allele is found in high frequency tants of our country were drawn from !"!TEACHING TOLERANCE geographically disparate portions of ancestors have been on this continent π LEARN MORE ∏ the human genetic spectrum. However, for 13 generations. This also means you soon after these populations were contain—from that time to now—the History reveals many brought together they began to amal- genetic material from as many as 8,192 instances in which gamate (sometimes willingly, some- individuals! And that estimate doesn’t times by force). Soon physical appear- even begin to touch the number of institutional racism ance was no longer a reliable determi- ancestors who came before your genes influenced science and nate of ancestry. arrived in North America. Although it is not possible to deter- vice versa. Learn how one Genetics of Race and Ancestry mine someone’s socially defined race physician’s theories —which We’ve determined that “biological by examining their DNA, it is possible races” in the human species do not to estimate the continental origin of we now know to be deeply exist. They cannot be determined by different segments of an individual’s flawed—were used to either physical or genetic measures; DNA. Remember that all of us have deep what we think of as “races” are socially ancestry in East Africa; the proportion justify chattel slavery. assigned sets of characteristics that of our variable DNA that falls into that Visit our sidebar at change depending on context. This category is about 85 percent. This means does not mean that there is not geo- that about 15 percent of our “recent” tolerance.org/ graphically based genetic variation DNA could potentially be differenti- samuel-morton-wrong found in our species. It simply means ated by continent or region within a con- that this variation is not su!cient to tinent. No single genetic marker is going describe biological races within the to be a reliable estimate of ancestry, so species. How then is the concept of statistical methods, such as maximum ancestry different from that of race? likelihood, are used to make estimates Understanding the di"erence requires of a person’s ancestry. understanding these two definitions: Ironically, ancestry studies have k BIOLOGICAL/GENETIC ANCESTRY revealed a great deal about the history is the proportion of recent ancestry displayed in an individual via genetic material inherited from one’s ancestral geographic origins. k SOCIAL/CULTURAL ANCES! TRY refers to the origin of atti- tudes, beliefs and behaviors dis- played by an individual.
Load more

Recommended publications
  • Ralstonia Solanacearum Race 3 Biovar 2 OriginalWebpage(SeeLink AtTheEndOfTheDocument)
    USDA-NRI Project: R. solanacearum race 3 biovar 2: detection, exclusion and analysis of a Select Agent Educational modules Ralstonia solanacearum race 3 biovar 2 Original webpage (see link at the end of the document) Author : Patrice G. Champoiseau of University of Florida Reviewers : Caitilyn Allen of University of Wisconsin; Jeffrey B. Jones , Carrie Harmon and Timur M. Momol of University of Florida Publication date : September 1 2, 2008 Supported by : The United States Department of Agriculture - National Research Initiative Program (2007 -2010) - See definitions of red-colored words in the glossary at the end of this document - Ralstonia solanacearum race 3 biovar 2 is the plant pathogen bacterium that causes brown rot (or bacterial wilt) of potato, Southern wilt of geranium, and bacterial wilt of tomato. R. solanacearum race 3 biovar 2 occurs in highlands in the tropics and in subtropical and some warm-temperate areas throughout the world. It has also occurred in cold-temperate regions in Europe, where several outbreaks of brown rot of potato have been reported in the last 30 years. It has been reported in more than 30 countries and almost all continents. In the United States, several introductions of R. solanacearum race 3 biovar 2 have already occurred as a result of importation of infested geranium cuttings from off-shore production sites, but the pathogen was apparently eradicated. However, because of the risk of its possible re-introduction through importation of infected plant material, and its potential to affect potato production in cold-temperate areas in the northern United States, R. solanacearum race 3 biovar 2 is considered a serious threat to the United States potato industry.
    [Show full text]
  • Microevolution: Species Concept Core Course: ZOOL3014 B.Sc. (Hons’): Vith Semester
    Microevolution: Species concept Core course: ZOOL3014 B.Sc. (Hons’): VIth Semester Prof. Pranveer Singh Clines A cline is a geographic gradient in the frequency of a gene, or in the average value of a character Clines can arise for different reasons: • Natural selection favors a slightly different form along the gradient • It can also arise if two forms are adapted to different environments separated in space and migration (gene flow) takes place between them Term coined by Julian Huxley in 1838 Geographic variation normally exists in the form of a continuous cline A sudden change in gene or character frequency is called a stepped cline An important type of stepped cline is a hybrid zone, an area of contact between two different forms of a species at which hybridization takes place Drivers and evolution of clines Two populations with individuals moving between the populations to demonstrate gene flow Development of clines 1. Primary differentiation / Primary contact / Primary intergradation Primary differentiation is demonstrated using the peppered moth as an example, with a change in an environmental variable such as sooty coverage of trees imposing a selective pressure on a previously uniformly coloured moth population This causes the frequency of melanic morphs to increase the more soot there is on vegetation 2. Secondary contact / Secondary intergradation / Secondary introgression Secondary contact between two previously isolated populations Two previously isolated populations establish contact and therefore gene flow, creating an
    [Show full text]
  • Major Human Races in the World (Classification of Human Races ) Dr
    GEOG- CC-13 M.A. Semester III ©Dr. Supriya e-text Paper-CC12 (U-III) Human and Social Geography Major Human races in The World (Classification of Human Races ) Dr. Supriya Assistant Professor (Guest) Ph. D: Geography; M.A. in Geography Post Doc. Fellow (ICSSR), UGC- NET-JRF Department of Geography Patna University, Patna Mob: 9006640841 Email: [email protected] Content Writer & Affiliation Dr Supriya, Asst. Professor (Guest), Patna University Subject Name Geography Paper Code CC-12 Paper Name Human and Social Geography Title of Topic Classification of Human Races Objectives To understand the concept of race and Examined the different views about classification of human races in the World Keywords Races, Caucasoid, Mongoloid, Negroid GEOG- CC-13 M.A. Semester III ©Dr. Supriya Classification of Human Races Dr. Supriya Concept of Race: A Race may be defined as division of mankind into classes of individuals possessing common physical characteristics, traits, appearance that is transmissible by descents & sufficient to characterize it as a distinct human type. Race is a biological grouping within human species distinguished or classified according to genetically transmitted differences. Anthropologists define race as a principal division of mankind, marked by physical characteristics that breed. According to Vidal de la Blache: “A race is great divisions of mankind, the members of which though individually vary, are characterized as a group by certain body characteristics as a group by certain body characteristics which are transmitted by nature & retained from one generation to another”. Race is a biological concept. The term race should not be used in connection with those grouping of mankind such as nation, religion, community & language which depends on feelings, ideas or habits of people and can be changes by the conscious wishes of the individual.
    [Show full text]
  • Microbial Risk Assessment Guideline
    EPA/100/J-12/001 USDA/FSIS/2012-001 MICROBIAL RISK ASSESSMENT GUIDELINE PATHOGENIC MICROORGANISMS WITH FOCUS ON FOOD AND WATER Prepared by the Interagency Microbiological Risk Assessment Guideline Workgroup July 2012 Microbial Risk Assessment Guideline Page ii DISCLAIMER This guideline document represents the current thinking of the workgroup on the topics addressed. It is not a regulation and does not confer any rights for or on any person and does not operate to bind USDA, EPA, any other federal agency, or the public. Further, this guideline is not intended to replace existing guidelines that are in use by agencies. The decision to apply methods and approaches in this guideline, either totally or in part, is left to the discretion of the individual department or agency. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. Environmental Protection Agency (EPA) (2012). Microbial Risk Assessment Guideline: Pathogenic Microorganisms with Focus on Food and Water. EPA/100/J-12/001 Microbial Risk Assessment Guideline Page iii TABLE OF CONTENTS Disclaimer .......................................................................................................................... ii Interagency Workgroup Members ................................................................................ vii Preface ............................................................................................................................. viii Abbreviations ..................................................................................................................
    [Show full text]
  • A Longitudinal Cline Characterizes the Genetic Structure of Human Populations in the Tibetan Plateau
    Dartmouth College Dartmouth Digital Commons Open Dartmouth: Published works by Dartmouth faculty Faculty Work 4-27-2017 A Longitudinal Cline Characterizes the Genetic Structure of Human Populations in the Tibetan Plateau Choongwon Jeong University of Chicago Benjamin M. Peter University of Chicago Buddha Basnyat Oxford University Maniraj Neupane Mountain Medicine Society of Nepal Geoff Childs Washington University in St. Louis See next page for additional authors Follow this and additional works at: https://digitalcommons.dartmouth.edu/facoa Part of the Biology Commons, and the Computational Biology Commons Dartmouth Digital Commons Citation Jeong, Choongwon; Peter, Benjamin M.; Basnyat, Buddha; Neupane, Maniraj; Childs, Geoff; Craig, Sienna; Novembre, John; and Di Rienzo, Anna, "A Longitudinal Cline Characterizes the Genetic Structure of Human Populations in the Tibetan Plateau" (2017). Open Dartmouth: Published works by Dartmouth faculty. 2500. https://digitalcommons.dartmouth.edu/facoa/2500 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 Open Dartmouth: Published works by Dartmouth faculty by an authorized administrator of Dartmouth Digital Commons. For more information, please contact [email protected]. Authors Choongwon Jeong, Benjamin M. Peter, Buddha Basnyat, Maniraj Neupane, Geoff Childs, Sienna Craig, John Novembre, and Anna Di Rienzo This article is available at Dartmouth Digital Commons: https://digitalcommons.dartmouth.edu/facoa/2500
    [Show full text]
  • Human Evolution: Pathogen Influence on Human Genetic Variation
    RESEARCH HIGHLIGHTS Nature Reviews Genetics | AOP, published online 22 November 2011; doi:10.1038/nrg3134 HUMAN EVOLUTION Pathogen influence on human genetic variation Human population genetic variation study, the statistical framework that by pathogens were heavily enriched in is known to be influenced by envi- was developed by Fumagalli et al. genes that are associated with autoim- ronmental pressures. By developing a enabled them to correlate allele mune diseases, such as coeliac disease novel statistical framework, Fumagalli frequencies for 500,000 SNPs in 55 and type 1 diabetes. and colleagues have been able to distinct human populations with local The finding that pathogens have discern the relative contributions of environmental factors, such as diet, left such a strong mark on human environmental factors to evolution climate conditions and pathogen load. genomes is perhaps not surprising of genomes, and they found that local Consistent with previous studies, given the influence that pathogens pathogen diversity had the strongest the authors found a greater correla- have on the human lifespan. However, role in the selective process. tion of these environmental factors the trace left by these pathogens Recent genome-wide human with the frequencies of genic SNPs at autoimmune disease gene loci population genetic analyses have and nonsynonymous SNPs than with suggests an intriguing relationship revealed that genes involved in traits non-genic SNPs. After correcting between achieving protection against such as immune function, skin pig- for demography, they showed that infection and maintaining disease- mentation and metabolism are non- pathogen diversity has the strongest causing mutations neutrally evolving sequences and have influence on local genetic variance, Hannah Stower therefore been under the influence of and they detected about 100 human environmental pressures.
    [Show full text]
  • How Race Becomes Biology: Embodiment of Social Inequality Clarence C
    AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 000:000–000 (2009) How Race Becomes Biology: Embodiment of Social Inequality Clarence C. Gravlee* Department of Anthropology, University of Florida, Gainesville, FL 32611-7305 KEY WORDS race; genetics; human biological variation; health; racism ABSTRACT The current debate over racial inequal- presents an opportunity to refine the critique of race in ities in health is arguably the most important venue for three ways: 1) to reiterate why the race concept is incon- advancing both scientific and public understanding of sistent with patterns of global human genetic diversity; race, racism, and human biological variation. In the 2) to refocus attention on the complex, environmental United States and elsewhere, there are well-defined influences on human biology at multiple levels of analy- inequalities between racially defined groups for a range sis and across the lifecourse; and 3) to revise the claim of biological outcomes—cardiovascular disease, diabetes, that race is a cultural construct and expand research on stroke, certain cancers, low birth weight, preterm deliv- the sociocultural reality of race and racism. Drawing on ery, and others. Among biomedical researchers, these recent developments in neighboring disciplines, I present patterns are often taken as evidence of fundamental a model for explaining how racial inequality becomes genetic differences between alleged races. However, a embodied—literally—in the biological well-being of growing body of evidence establishes the primacy of racialized groups and individuals. This model requires a social inequalities in the origin and persistence of racial shift in the way we articulate the critique of race as bad health disparities.
    [Show full text]
  • Global Clues to the Nature of Genomic Mutations in Humans
    INSIGHT POPULATION GENETICS Global clues to the nature of genomic mutations in humans An analysis of worldwide human genetic variation reveals the footprints of ancient changes in genomic mutation processes. AYLWYN SCALLY factors may reflect recent evolutionary events, Related research article Harris K, Pritchard particularly the divergence of human popula- JK. 2017. Rapid evolution of the human tions and their global dispersal within the last mutation spectrum. eLife 6:e24284. doi: 10. 100,000 years. One way to address this question would be 7554/eLife.24284 to collect genomic and other data for thousands of families, identify de novo mutations in each of the offspring, and then analyse the factors con- tributing to them. However, this approach is ll children inherit a mixture of chromo- extremely demanding in terms of the resources somal sequences from their parents, needed. Now, in eLife, Kelley Harris and Jona- A and although the copying process than Pritchard of Stanford University report how involved is extremely accurate, some errors they have taken an alternative occur. We refer to such errors as de novo (new) approach (Harris and Pritchard, 2017) that germline mutations, and when they are passed involved using a dataset of whole-genome on to subsequent generations, these mutations sequences for 2504 individuals from 26 different are the raw material on which natural selection populations around the world (Auton et al., works and the source of all genetic differences 2015). Consider that any genetic variant in this between populations and species. Most have dataset, even if it is found today in many individ- negligible or minor effects, but some on very uals, was once a de novo mutation in a single rare occasions are responsible for serious ancestor.
    [Show full text]
  • Race As a Legal Concept
    University of Colorado Law School Colorado Law Scholarly Commons Articles Colorado Law Faculty Scholarship 2012 Race as a Legal Concept Justin Desautels-Stein University of Colorado Law School Follow this and additional works at: https://scholar.law.colorado.edu/articles Part of the Conflict of Laws Commons, Jurisprudence Commons, Law and Race Commons, and the Legal History Commons Citation Information Justin Desautels-Stein, Race as a Legal Concept, 2 COLUM. J. RACE & L. 1 (2012), available at https://scholar.law.colorado.edu/articles/137. Copyright Statement Copyright protected. Use of materials from this collection beyond the exceptions provided for in the Fair Use and Educational Use clauses of the U.S. Copyright Law may violate federal law. Permission to publish or reproduce is required. This Article is brought to you for free and open access by the Colorado Law Faculty Scholarship at Colorado Law Scholarly Commons. It has been accepted for inclusion in Articles by an authorized administrator of Colorado Law Scholarly Commons. For more information, please contact [email protected]. +(,121/,1( Citation: 2 Colum. J. Race & L. 1 2012 Provided by: William A. Wise Law Library Content downloaded/printed from HeinOnline Tue Feb 28 10:02:56 2017 -- Your use of this HeinOnline PDF indicates your acceptance of HeinOnline's Terms and Conditions of the license agreement available at http://heinonline.org/HOL/License -- The search text of this PDF is generated from uncorrected OCR text. -- To obtain permission to use this article beyond the scope of your HeinOnline license, please use: Copyright Information 2012 COLUMBIA JOURNAL OF RACE AND LAW RACE AS A LEGAL CONCEPT JUSTIN DESAUTELS-STEIN* Race is a /el cocpangie a/Il corncepts, it is a matrix of rules.
    [Show full text]
  • Racial Categorization in the 2010 Census
    U.S. COMMISSION ON CIVIL RIGHTS RACIAL CATEGORIZATION IN THE 2010 CENSUS BRIEFING REPORT U.S. COMMISSION ON CIVIL RIGHTS Washington, DC 20425 Official Business Penalty for Private Use $300 MARCH 2009 Visit us on the Web: www.usccr.gov U.S. Commission on Civil Rights The U.S. Commission on Civil Rights is an independent, bipartisan agency established by Congress in 1957. It is directed to: • Investigate complaints alleging that citizens are being deprived of their right to vote by reason of their race, color, religion, sex, age, disability, or national origin, or by reason of fraudulent practices. • Study and collect information relating to discrimination or a denial of equal protection of the laws under the Constitution because of race, color, religion, sex, age, disability, or national origin, or in the administration of justice. • Appraise federal laws and policies with respect to discrimination or denial of equal protection of the laws because of race, color, religion, sex, age, disability, or national origin, or in the administration of justice. • Serve as a national clearinghouse for information in respect to discrimination or denial of equal protection of the laws because of race, color, religion, sex, age, disability, or national origin. • Submit reports, findings, and recommendations to the President and Congress. • Issue public service announcements to discourage discrimination or denial of equal protection of the laws. Members of the Commission Gerald A. Reynolds, Chairman Abigail Thernstrom, Vice Chair Todd Gaziano Gail Heriot Peter N. Kirsanow Arlan D. Melendez Ashley L. Taylor, Jr. Michael Yaki Martin Dannenfelser, Staff Director U.S. Commission on Civil Rights 624 Ninth Street, NW Washington, DC 20425 (202) 376-8128 (202) 376-8116 TTY www.usccr.gov This report is available on disk in ASCII Text and Microsoft Word 2003 for persons with visual impairments.
    [Show full text]
  • Theory of Hybrids 7 the Target a Natural Kind Such As Race and Gender
    A Theory of Hybrids 1 [Forthcoming in Asian Journal of Social Psychology] An Essentialist Theory of “Hybrids”: From Animal Kinds to Ethnic Categories and Race Wolfgang Wagner1, 2 Nicole Kronberger1 Motohiko Nagata3 Ragini Sen4 Peter Holtz1 Fátima Flores Palacios5 WORD COUNT: 10,613 1 Johannes Kepler University, Linz, Austria 2 University of the Basque Country, San Sebastián, Spain 3 Kyoto University, Kyoto, Japan 4 Logistics, Mumbai, India 5 Universidad Nacional Autónoma de México, México D.F., Mexico A Theory of Hybrids 2 Abstract This paper presents a theory of the perception of hybrids resulting from crossbreeding natural animals that pertain to different species and of children parented by couples with a mixed ethnic or racial background. The theory states that natural living beings including humans are perceived as possessing a deeply ingrained characteristic that is called essence or “blood” or genes in everyday discourse and that uniquely determines their category membership. If by whatever means genes or essences of two animals of different species are combined in a hybrid, the two incompatible essences collapse, leaving the hybrid in a state of non-identity and non-belonging. People despise this state and reject the hybrid (Study 1). This devaluation effect holds with cross-kind hybrids and with hybrids that arise from genetically combining animals from incompatible habitats across three cultures, Austria, India and Japan (Study 2). In the social world, groups and ethnic or racial categories frequently are essentialized in an analog way. When people with an essentialist mindset judge ethnically or racially mixed offspring they perceive a collapse of ethnic or racial essence and, consequentially, denigrate these children as compared to children from “pure” ingroup or outgroup parents (Study 3).
    [Show full text]
  • Human Genetic Variation Section 3 Learning Objectives
    Human Genetic Variation Section 3 Learning objectives • Describe differences in types of genetic variation and how they affect phenotypes. • Identify inheritance patterns of genotype-phenotype relationships. • Describe the differences and the pros and cons of sequencing vs genotyping. Zoom Poll Our Genome in Numbers 23 chromosome pairs 3.2 billion base-pairs (A,C,G,T) ~20,000 genes ~1.5% of the genome is coding DNA Genetic variation to phenotype variation The changes in DNA What we actually see (disease, trait) Single base change = Single Nucleotide Polymorphism/Variant (SNP/SNV) Genetic variant – changes in amino acid codons Synonymous mutation Nonsynonymous is usually worse than synonymous Nonsense mutation Nonsynonymous mutations Missense mutation Some missense mutations can be less bad Both polar Deletions/insertions “Frameshifts” Mutations happen all the time, with every replication Human genome mutation rate is ~1.1×10−8 per site per generation. Human genome is over 3 billion base pairs. Each genome: 3,000,000,000 sites Mutation rate: 0.000000011 errors/site How many new mutations do you expect in expect in each cell replication? Zoom Poll Sometimes we don’t change the protein itself… A gene includes a lot of DNA that doesn’t become protein A gene includes a lot of DNA that doesn’t become protein A variant here can change gene “expression” A gene includes a lot of DNA that doesn’t become protein Or here can change the “splice site” to make a different protein Zoom breakout – discuss Q1 Besides single base changes, what types of changes can we have? Genetic Variation – structural variation tandem repeats (Huntington’s disease) The normal function of huntingtin is unknown.
    [Show full text]