Critical race theory

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Critical_race_theory 

Critical race theory (CRT) is a framework of analysis and an academic movement of civil-rights scholars and activists who seek to examine the intersection of race and law in the United States and to challenge mainstream American liberal approaches to racial justice. CRT examines social, cultural, and legal issues primarily as they relate to race and racism in the United States. A tenet of CRT is that racism and disparate racial outcomes are the result of complex, changing, and often subtle social and institutional dynamics, rather than explicit and intentional prejudices of individuals.

CRT originated in the mid-1970s in the writings of several American legal scholars, including Derrick Bell, Alan Freeman, Kimberlé Crenshaw, Richard Delgado, Cheryl Harris, Charles R. Lawrence III, Mari Matsuda, and Patricia J. Williams. It emerged as a movement by the 1980s, reworking theories of critical legal studies (CLS) with more focus on race. CRT is grounded in critical theory and draws from thinkers such as Antonio Gramsci, Sojourner Truth, Frederick Douglass, and W. E. B. DuBois, as well as the Black Power, Chicano, and radical feminist movements from the 1960s and 1970s.

CRT scholars view race as an intersectional social construct that is not "biologically grounded and natural", and that advances the interests of white people at the expense of persons of other races. In the field of legal studies, CRT emphasizes that formally colorblind laws can still have racially discriminatory outcomes. A key CRT concept is intersectionality, which emphasizes that race can intersect with other identities (such as gender and class) to produce complex combinations of power and advantage.

Academic critics of CRT argue that CRT elevates storytelling over evidence and reason, rejects the concepts of truth and merit, and opposes liberalism. Since 2020, conservative U.S. lawmakers have sought to ban or restrict the instruction of critical race theory along with other anti‑racism education in primary and secondary schools. These lawmakers have been accused of misrepresenting the tenets and importance of CRT and that the goal of their restrictions is to broadly silence discussions of racism, equality, social justice, and the history of race.

Definitions

In his introduction to the comprehensive 1995 publication of critical race theory's key writings, Cornel West describes CRT as "an intellectual movement that is both particular to our postmodern (and conservative) times and part of a long tradition of human resistance and liberation."

Law professor Roy L. Brooks defines critical race theory in 1994 as "a collection of critical stances against the existing legal order from a race-based point of view". Education Week describes the core of CRT as the idea that race is a social construct and racism is neither an individual bias nor prejudice—it is "embedded in the legal system" and supplemented with policies and procedures.

University of Alabama School of Law professor Richard Delgado, a co-founder of critical race theory, and legal writer Jean Stefancic define CRT as "a collection of activists and scholars interested in studying and transforming the relationship among race, racism, and power".

Gloria Ladson-Billings, a pedagogical theorist who introduced CRT to the field of education in 1994, describes CRT as an "interdisciplinary approach that seeks to understand and combat race inequity in society."

Early years

In the 1998 article, "Critical Race Theory: Past, Present, and Future", Delgado and Stefancic traces the origins of CRT to the early writings of Derrick Bell, including his 1976 Yale Law Journal article, "Serving Two Masters" and his 1980 Harvard Law Review article entitled "Brown v. Board of Education and the Interest-Convergence Dilemma".

Bell began his career as a civil rights lawyer, where he successfully litigated 300 civil rights cases for the NAACP in Mississippi. Later as a professor at Harvard Law School, Bell developed new courses that studied American law through a racial lens. Delgado and Stefancic, who together wrote Critical Race Theory: a Introduction in 2001, described Bell's "interest convergence" as a "means of understanding Western racial history". The focus on desegregation after the 1954 Supreme Court decision in Brown v. Board of Education—declaring school segregation unconstitutional—left "civil-rights lawyers compromised between their clients' interests and the law". The concern of many Black parents—for their children's access to better education—was being eclipsed by the interests of litigators who wanted a "breakthrough" in their "pursuit of racial balance in schools". In 1995, Cornel West said that Bell was "virtually the lone dissenter" writing in leading law reviews who challenged basic assumptions about how the law treated people of color.

Bell compiled his own course materials which were published in 1970 under the title, Race, racism, and American law. He became Harvard Law School's first Black tenured professor in 1971. Bell resigned in 1980 because of what he viewed as the university's discriminatory practices, became the dean at University of Oregon School of Law and later returned to Harvard as a visiting professor. While he was absent from Harvard, his supporters organized protests against Harvard's lack of racial diversity in the curriculum, in the student body and in the faculty. One student-led initiative included the creation of an alternative course in 1981—based on Bell's course and textbook—where students brought in visiting professors, such as Charles Lawrence, Linda Greene, Neil Gotanda, and Richard Delgado, to teach chapter by chapter from Race, racism, and American law.

The students called for faculty of color to teach the new courses following Bell's departure. The university rejected student requests, saying no sufficiently qualified black instructor existed. Legal scholar Randall Kennedy writes that some students had "felt affronted" by Harvard's choice to employ an "archetypal white liberal... in a way that precludes the development of black leadership".

Delgado and Stefancic also cite the work of Alan Freeman in the 1970s as formative to critical race theory. In his 1978 Minnesota Law Review article Freeman reinterpreted, through a critical legal studies perspective, how the Supreme Court oversaw civil rights legislation from 1953 to 1969 under the Warren Court. He criticized the narrow interpretation of the law which denied relief for victims of racial discrimination. In his article, Freeman describes two perspectives on the concept of racial discrimination: that of victim or perpetrator. Racial discrimination to the victim includes both objective conditions and the "consciousness associated with those objective conditions". To the perpetrator, racial discrimination consists only of actions without consideration of the objective conditions experienced by the victims, such as the "lack of jobs, lack of money, lack of housing".

In 1989, Kimberlé Crenshaw, Neil Gotanda, and Stephanie Phillips organized a workshop at the University of Wisconsin-Madison entitled "New Developments in Critical Race Theory". The organizers coined the term "Critical Race Theory" to be an "intersection of critical theory and race, racism, and the law." Crenshaw chose Harvard to study under Bell, whose work she was introduced to at Cornell. Crenshaw organized the alternative course using Bell's course materials. She was part of a group of students who considered themselves part of the "post-civil rights generation".

Following this meeting, legal scholars began publishing a higher volume of works employing critical race theory, including over "300 leading law review articles" and books. In 1990, Duncan Kennedy published his article on affirmative action in legal academia in the Duke Law Journal, and Anthony E. Cook published his article "Beyond Critical Legal Studies" in the Harvard Law Review. In 1991, Patricia Williams published The Alchemy of Race and Rights, while Derrick Bell published Faces at the Bottom of the Well in 1992. Cheryl I. Harris published her 1993 Harvard Law Review article "Whiteness as Property" in which she described how passing led to benefits akin to owning property. In 1995, two dozen legal scholars contributed to a major compilation of key writings on critical race theory.

Though CLS criticized the legal system's role in generating and legitimizing oppressive social structures, it did not tend to provide alternatives. CRT scholars such as Derrick Bell and Alan Freeman argue that failure to include race and racism in its analysis prevented CLS from suggesting new directions for social transformation. CRT criticized CLS for focusing too much on class and economic structures and not enough on race.

By the early 1990s, key concepts and features of CRT had emerged. Bell had introduced his concept of "interest convergence" in his 1973 article. He developed the concept of racial realism in a 1992 series of essays and book, Faces at the bottom of the well: the permanence of racism. He said that Black people needed to accept that the civil rights era legislation would not on its own bring about progress in race relations; anti-Black racism in the US was a "permanent fixture" of American society; and equality was "impossible and illusory" in the US. Crenshaw had introduced and developed the concept of intersectionality in her 1989 article in the University of Chicago Legal Forum and her 1990 article in the Stanford Law Review.

Growth and expansion

In 1995, pedagogical theorists Gloria Ladson-Billings and William F. Tate began applying the critical race theory framework in the field of education. In their 1995 article Ladson-Billings and Tate described the role of the social construction of white norms and interests in education. They sought to better understand inequities in schooling. Scholars have since expanded work to explore issues including school segregation in the U.S.; relations between race, gender, and academic achievement; pedagogy; and research methodologies.

By 2009, according to University of Edinburgh philosophy professor, Tommy J. Curry, many race scholars had adopted CRT's view that race was socially constructed, not "biologically grounded and natural".

As of 2002, over 20 American law schools and at least three non-American law schools offered critical race theory courses or classes. Critical race theory is also applied in the fields of education, political science, women's studies, ethnic studies, communication, sociology, and American studies. Other movements developed that apply critical race theory to specific groups. These include the Latino-critical (LatCrit), queer-critical, and Asian-critical movements. These continued to engage with the main body of critical theory research, over time developing independent priorities and research methods. CRT has also been taught internationally, including in the United Kingdom and Australia.

Common themes

Common themes that are characteristic of critical race theory, as documented by scholars such as Richard Delgado and Jean Stefancic, include:

• Critique of liberalism: Critical race theory scholars question foundational liberal concepts such as Enlightenment rationalism, legal equality and constitutional neutrality, and they challenge the incrementalist approach of traditional civil-rights discourse. They favor a race-conscious approach to social transformation, critiquing liberal ideas such as affirmative action, color blindness, role modeling, or the merit principle preferring political organizing, in contrast to liberalism's reliance on rights-based remedies.
• Storytelling, counter-storytelling, and "naming one's own reality": The use of narrative (storytelling) to illuminate and explore lived experiences of racial oppression. Bryan Brayboy has emphasized the epistemic importance of storytelling in Indigenous-American communities as superseding that of theory, and has proposed a Tribal Critical Race Theory (TribCrit).
• Revisionist interpretations of American civil rights law and progress: Criticism of civil-rights scholarship and anti-discrimination law, such as Brown v. Board of Education. Derrick Bell, one of CRT's founders, argues that civil-rights advances for black people coincided with the self-interest of white elitists, which Bell termed interest convergence. Likewise, Mary L. Dudziak performed extensive archival research in the U.S. Department of State and Department of Justice and concluded that U.S. government support for civil-rights legislation "was motivated in part by the concern that racial discrimination harmed the United States' foreign relations".
• Intersectional theory: The examination of race, sex, class, national origin, and sexual orientation, and how their intersections play out in various settings, such as how the needs of a Latina female are different from those of a black male, and whose needs are promoted.
• Standpoint epistemology: The view that a member of a minority has an authority and ability to speak about racism that members of other racial groups do not have, and that this can expose the racial neutrality of law as false.
• Essentialism vs. anti-essentialism: Delgado and Stefancic write, "Scholars who write about these issues are concerned with the appropriate unit for analysis: Is the black community one, or many, communities? Do middle- and working-class African-Americans have different interests and needs? Do all oppressed peoples have something in common?" This is a look at the ways that oppressed groups may share in their oppression but also have different needs and values that need to be looked at differently. It is a question of how groups can be essentialized or are unable to be essentialized.
• Structural determinism: Exploration of how "the structure of legal thought or culture influences its content" in a way that determines social outcomes.
• Empathetic fallacy: Believing that one can change a narrative by offering an alternative narrative in hopes that the listener's empathy will quickly and reliably take over. In this view, empathy is not enough to change racism as most people are not exposed to those different from themselves, and people mostly seek out information about their own group.
• Non-white cultural nationalism/separatism: The exploration of more radical views that argue for separation and reparations as a form of foreign aid (including black nationalism).

Internalization

Karen Pyke documented the theoretical element of internalized racism or internalized racial oppression, where victims of racism start to believe they are inferior to whites and white culture. The internalizing of racism is not due to any weakness, ignorance, inferiority, psychological defect, gullibility, or other shortcomings of the oppressed. Instead, it is how authority and power in all aspects of society contribute to feelings of inequality.

Institutional racism

Camara Phyllis Jones defines institutionalized racism as

differential access to the goods, services, and opportunities of society by race. Institutionalized racism is normative, sometimes legalized and often manifests as inherited disadvantage. It is structural, having been absorbed into our institutions of custom, practice, and law, so there need not be an identifiable offender. Indeed, institutionalized racism is often evident as inaction in the face of need, manifesting itself both in material conditions and in access to power. With regard to the former, examples include differential access to quality education, sound housing, gainful employment, appropriate medical facilities, and a clean environment.

Influence of critical legal studies

Critical race theory shares many intellectual commitments with critical theory, critical legal studies, feminist jurisprudence, and postcolonial theory. Tommy J. Curry has written that the epistemic convergences with such approaches are emphasized due to the idealist turn in critical race theory. The latter, as Curry explains, is interested in discourse (i.e., how individuals speak about race) and the theories of white Continental philosophers, over and against the structural and institutional accounts of white supremacy which were at the heart of the realist analysis of racism introduced in Derrick Bell's early works, and articulated through such Black thinkers as W. E. B. Du Bois, Paul Robeson, and Judge Robert L. Carter.

Critical race theory draws on the priorities and perspectives of both critical legal studies and conventional civil rights scholarship, while also sharply contesting both of these fields. Critical race theory's theoretical elements are provided by a variety of sources. Angela P. Harris describes critical race theory as sharing "a commitment to a vision of liberation from racism through right reason" with the civil rights tradition. It deconstructs some premises and arguments of legal theory and simultaneously holds that legally constructed rights are incredibly important. As described by Derrick Bell, critical race theory in Harris' view is committed to "radical critique of the law (which is normatively deconstructionist) and... radical emancipation by the law (which is normatively reconstructionist)".

Applications

Scholars of critical race theory have focused, with some particularity, on the issues of hate crime and hate speech. In response to the opinion of the U.S. Supreme Court in the hate speech case of R.A.V. v. City of St. Paul (1992), in which the Court struck down an anti-bias ordinance as applied to a teenager who had burned a cross, Mari Matsuda and Charles Lawrence argued that the Court had paid insufficient attention to the history of racist speech and the actual injury produced by such speech.

Critical race theorists have also argued in favor of affirmative action. They propose that so-called merit standards for hiring and educational admissions are not race-neutral and that such standards are part of the rhetoric of neutrality through which whites justify their disproportionate share of resources and social benefits.

Criticism

Academics and jurists

According to the Encyclopedia Britannica, "aspects of CRT have been criticized by legal scholars and jurists from across the political spectrum." Critics say it contains a "postmodernist-inspired skepticism of objectivity and truth", and say it opposes "the traditional liberal ideals of neutrality, equality, and fairness in the law and legal procedures and of unreasonably spurning the notion of objective standards of merit in academia and in public and private employment, instead interpreting any racial inequity or imbalance in legal, academic, or economic outcomes as proof of institutional racism and as grounds for directly imposing racially equitable outcomes in those realms." Proponents of CRT have also been accused of treating even well-meaning criticism of CRT as evidence of latent racism.

In a 1997 book, law professors Daniel A. Farber and Suzanna Sherry criticized CRT for over-reliance on personal narratives instead of testing hypotheses against measurable data. CRT scholars including Crenshaw, Delgado, and Stefancic have argued that such critiques represent dominant modes within social science which tend to exclude people of color. Delgado and Stefancic responded that "In these realms [social science and politics], truth is a social construct created to suit the purposes of the dominant group." Farber and Sherry have also argued that anti-meritocratic tenets in critical race theory, critical feminism, and critical legal studies may unintentionally lead to antisemitic and anti-Asian implications. They write that the success of Jews and Asians within what critical race theorists posit to be a structurally unfair system may lend itself to allegations of cheating and advantage-taking. In response, Delgado and Stefancic write that there is a difference between criticizing an unfair system and criticizing individuals who perform well inside that system.

In a 1999 Boston College Law Review article titled Race, Equality and the Rule of Law: Critical Race Theory's Attack on the Promises of Liberalism, First Amendment lawyer Jeffrey J. Pyle argued that critical race theory undermined confidence in the rule of law. He wrote that "critical race theorists attack the very foundations of the liberal legal order, including equality theory, legal reasoning, Enlightenment rationalism and neutral principles of constitutional law".

Political controversies

Critical race theory stirred controversy in the United States beginning in the 1980s, for critiquing color blindness, promoting the use of narrative in legal studies, advocating "legal instrumentalism" as opposed to ideal-driven uses of the law, analyzing the U.S. Constitution and existing law as constructed according to and perpetuating racial power, and encouraging legal scholars to promote racial equity. An example of an instrumentalist approach is attorney Johnnie Cochran's defense in the O. J. Simpson murder case, in which Cochran urged the jury to acquit Simpson in spite of the evidence against him as a form of jury nullification as payback for the United States' racist past. In the run-up to and aftermath of the 2020 U.S. presidential election, opposition to critical race theory was adopted as a campaign theme by Donald Trump and various conservative commentators on Fox News and right-wing talk radio shows.

1990s

Lani Guinier, Bill Clinton's nominee for Assistant Attorney General, was attacked by Republicans in part for her association with CRT, in an attempt to block her nomination. Clinton withdrew the nomination due to disagreements with her legal philosophy.

2010s

In 2010, a Mexican-American studies program in Tucson, Arizona, was halted because of a state law forbidding public schools from offering race-conscious education in the form of "advocat[ing] ethnic solidarity instead of the treatment of pupils as individuals". Certain books, including a primer on CRT, were banned from the curriculum. Matt de la Peña's young-adult novel Mexican WhiteBoy was banned for "containing 'critical race theory'" according to state officials. The ban on ethnic-studies programs was later deemed unconstitutional on the grounds that the state showed discriminatory intent: "Both enactment and enforcement were motivated by racial animus", federal Judge A. Wallace Tashima ruled.

2020s

Australia

In June 2021, following media reports that the proposed national curriculum was "preoccupied with the oppression, discrimination and struggles of Indigenous Australians", the Australian Senate approved a motion tabled by right-wing senator Pauline Hanson calling on the federal government to reject CRT, despite it not being included in the curriculum.

United Kingdom

Conservatives within the UK government began to criticize CRT in late 2020. Equalities Minister Kemi Badenoch, who is of Nigerian descent, said during a parliamentary debate to mark Black History Month:

We do not want to see teachers teaching their pupils about white privilege and inherited racial guilt  [...] Any school which teaches these elements of critical race theory, or which promotes partisan political views such as defunding the police without offering a balanced treatment of opposing views, is breaking the law."

In an open letter, 101 writers of the Black Writers' Guild denounced Badenoch for remarks about popular anti-racism books such as White Fragility and Why I'm No Longer Talking to White People About Race, made in an interview in The Spectator, in which she said, "many of these books—and, in fact, some of the authors and proponents of critical race theory—actually want a segregated society".

United States

Conservative lawmakers and activists have used the term "critical race theory" as a "catchall phrase for nearly any examination of systemic racism", according to The Washington Post. In September 2020, after seeing a piece on Fox News in which conservative activist Christopher Rufo denounced CRT, Donald Trump issued an executive order directing agencies of the United States federal government to cancel funding for programs that mention "white privilege" or "critical race theory", on the basis that it constituted "divisive, un-American propaganda" and that it was "racist". Rufo's wrote on Twitter, "The goal is to have the public read something crazy in the newspaper and immediately think 'critical race theory'."

In a speech on September 17, 2020, Trump denounced critical race theory and announced the formation of the 1776 Commission to promote "patriotic education". On January 20, 2021, Joe Biden rescinded Trump's order and dissolved the 1776 Commission. Opposition to what was purported to be critical race theory was subsequently adopted as a major theme by several conservative think tanks and pressure groups, including the Heritage Foundation, the Idaho Freedom Foundation and the American Legislative Exchange Council.

In early 2021, bills were introduced to restrict teaching critical race theory in public schools, including Idaho, Iowa, Oklahoma, Tennessee and Texas. Several of these bills specifically mention "critical race theory" or single out the New York Times 1619 Project. CRT is only taught at a university level, though some lower-level curricula have reflected basic themes of CRT.

In mid-April 2021, a bill was introduced in the Idaho legislature that would effectively ban any educational entity from teaching or advocating sectarianism, including critical race theory or other programs involving social justice. On May 4, 2021, the bill was signed into law by Governor Brad Little. On June 10, 2021, the Florida State Board of Education unanimously voted to ban public schools from teaching critical race theory at the urging of governor Ron DeSantis. As of July 2021, 10 U.S. states have introduced bills or taken other steps that would restrict teaching critical race theory, and 26 others were in the process of doing so. In June 2021, the American Association of University Professors, the American Historical Association, the Association of American Colleges and Universities, and PEN America released a joint statement stating their opposition to such legislation, and by August 2021, 167 professional organizations had signed onto the statement. In August 2021, the Brookings Institution recorded that eight states—Idaho, Oklahoma, Tennessee, Texas, Iowa, New Hampshire, Arizona, and South Carolina—had passed regulation on the issue, though also noted that none of the bills that passed, with the exception of Idaho's, actually contained the words "critical race theory." Brookings also noted that these laws often extend beyond race to discussions of gender. Critics^[who?] have called the state laws a memory law and a confirmation of the idea that racism is codified into the law of the United States.

Subfields

Within critical race theory, various sub-groupings focus on issues and nuances unique to particular ethno-racial and/or marginalized communities. This includes the intersection of race with disability, ethnicity, gender, sexuality, class, or religion. For example, disability critical race studies (DisCrit), critical race feminism (CRF), Hebrew Crit (HebCrit), Black Critical Race Theory (Black Crit), Latino critical race studies (LatCrit), Asian American critical race studies (AsianCrit), South Asian American critical race studies (DesiCrit), and American Indian critical race studies (sometimes called TribalCrit). CRT methodologies have also been applied to the study of white immigrant groups. CRT has spurred some scholars to call for a second wave of whiteness studies, which is now a small offshoot known as Second Wave Whiteness (SWW). Critical race theory has also begun to spawn research that looks at understandings of race outside the United States.

Disability critical race theory

Another offshoot field is disability critical race studies (DisCrit), which combines disability studies and CRT to focus on the intersection of disability and race.

Latino critical race theory

Latino critical race theory (LatCRT or LatCrit) is a research framework that outlines the social construction of race as central to how people of color are constrained and oppressed in society. Race scholars developed LatCRT as a critical response to the "problem of the color line" first explained by W. E. B. Du Bois. While CRT focuses on the Black–White paradigm, LatCRT has moved to consider other racial groups, mainly Chicana/Chicanos, as well as Latinos/as, Asians, Native Americans/First Nations, and women of color.

In Critical Race Counterstories along the Chicana/Chicano Educational Pipeline, Tara J. Yosso discusses how the constraint of POC can be defined. Looking at the differences between Chicana/o students, the tenets that separate such individuals are: the intercentricity of race and racism, the challenge of dominant ideology, the commitment to social justice, the centrality of experience knowledge, and the interdisciplinary perspective.

LatCRTs main focus is to advocate social justice for those living in marginalized communities (specifically Chicana/os), who are guided by structural arrangements that disadvantage people of color. Social institutions function as dispossessions, disenfranchisement, and discrimination over minority groups, while LatCRT seeks to give voice to those who are victimized. In order to do so, LatCRT has created two common themes:

First, CRT proposes that white supremacy and racial power are maintained over time, a process that the law plays a central role in. Different racial groups lack the voice to speak in this civil society, and, as such, CRT has introduced a new critical form of expression, called the voice of color. The voice of color is narratives and storytelling monologues used as devices for conveying personal racial experiences. These are also used to counter metanarratives that continue to maintain racial inequality. Therefore, the experiences of the oppressed are important aspects for developing a LatCRT analytical approach, and it has not been since the rise of slavery that an institution has so fundamentally shaped the life opportunities of those who bear the label of criminal.

Secondly, LatCRT work has investigated the possibility of transforming the relationship between law enforcement and racial power, as well as pursuing a project of achieving racial emancipation and anti-subordination more broadly. Its body of research is distinct from general critical race theory in that it emphasizes immigration theory and policy, language rights, and accent- and national origin-based forms of discrimination. CRT finds the experiential knowledge of people of color and draws explicitly from these lived experiences as data, presenting research findings through storytelling, chronicles, scenarios, narratives, and parables.

Asian critical race theory

Asian critical race theory looks at the influence of race and racism on Asian Americans and their experiences in the U.S. education system. Like Latino critical race theory, Asian critical race theory is distinct from the main body of CRT in its emphasis on immigration theory and policy.

BRAIN Initiative

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/BRAIN_Initiative

Understanding how the brain works is arguably one of the greatest scientific challenges of our time.

–Alivisatos et al.

The White House BRAIN Initiative (Brain Research through Advancing Innovative Neurotechnologies), is a collaborative, public-private research initiative announced by the Obama administration on April 2, 2013, with the goal of supporting the development and application of innovative technologies that can create a dynamic understanding of brain function.

This activity is a Grand Challenge focused on revolutionizing our understanding of the human brain, and was developed by the White House Office of Science and Technology Policy (OSTP) as part of a broader White House Neuroscience Initiative. Inspired by the Human Genome Project, BRAIN aims to help researchers uncover the mysteries of brain disorders, such as Alzheimer's and Parkinson's diseases, depression, and traumatic brain injury (TBI).

Participants in BRAIN and affiliates of the project include DARPA and IARPA as well as numerous private companies, universities, and other organizations in the United States, Australia, Canada, and Denmark.

Background

The BRAIN Initiative reflects a number of influences, stemming back over a decade. Some of these include: planning meetings at the National Institutes of Health that led to the NIH's Blueprint for Neuroscience Research; workshops at the National Science Foundation (NSF) on cognition, neuroscience, and convergent science, including a 2006 report on "Grand Challenges of Mind and Brain"; reports from the National Research Council and the Institute of Medicine's Forum on Neuroscience and Nervous System Disorders, including "From Molecules to Mind: Challenges for the 21st Century," a report of a June 25, 2008 Workshop on Grand Challenges in Neuroscience.; years of research and reports from scientists and professional societies; and congressional interest.

One important activity was the Brain Activity Map Project. In September 2011, molecular biologist Miyoung Chun of The Kavli Foundation organized a conference in London, at which scientists first put forth the idea of such a project. At subsequent meetings, scientists from US government laboratories, including members of the Office of Science and Technology Policy, and from the Howard Hughes Medical Institute and the Allen Institute for Brain Science, along with representatives from Google, Microsoft, and Qualcomm, discussed possibilities for a future government-led project.

Other influences included the interdisciplinary "Decade of the Mind" project led by James L. Olds, who is currently the Assistant Director for Biological Sciences at NSF, and the "Revolutionizing Prosthetics" project at DARPA, led by Dr. Geoffrey Ling and shown on 60 Minutes in April 2009.

Development of the plan for the BRAIN Initiative within the Executive Office of the President (EOP) was led by OSTP and included the following EOP staff: Philip Rubin, then Principal Assistant Director for Science and leader of the White House Neuroscience Initiative; Thomas Kalil, Deputy Director for Technology and Innovation; Cristin Dorgelo, then Assistant Director for Grand Challenges, and later Chief of Staff at OSTP; and Carlos Peña, Assistant Director for Emerging Technologies and currently the Division Director for the Division of Neurological and Physical Medicine Devices, in the Office of Device Evaluation, Center for Devices and Radiological Health (CDRH), at the U.S. Food and Drug Administration (FDA).

Announcement

NIH Director Dr. Francis Collins and President Barack Obama announcing the BRAIN Initiative

On April 2, 2013, at a White House event, President Barack Obama announced The BRAIN Initiative, with proposed initial expenditures for fiscal year 2014 of approximately $110 million from the Defense Advanced Research Projects Agency (DARPA), the National Institutes of Health (NIH), and the National Science Foundation (NSF). The President also directed the Presidential Commission for the Study of Bioethical Issues to explore the ethical, legal, and societal implications raised by the initiative and by neuroscience in general. Additional commitments were also made by the Allen Institute for Brain Science, the Howard Hughes Medical Institute, and The Kavli Foundation. The NIH also announced the creation of a working group of the Advisory Committee to the Director, led by neuroscientists Cornelia Bargmann and William Newsome and with ex officio participation from DARPA and NSF, to help shape NIH's role in the BRAIN Initiative. NSF planned to receive advice from its directorate advisory committees, from the National Science Board, and from a series of meetings bringing together scientists in neuroscience and related areas.

Experimental approaches

Further information: Brain mapping, Neuroinformatics, and Nanobiotechnology

News reports said the research would map the dynamics of neuron activity in mice and other animals and eventually the tens of billions of neurons in the human brain.

In a 2012 scientific commentary outlining experimental plans for a more limited project, Alivisatos et al. outlined a variety of specific experimental techniques that might be used to achieve what they termed a "functional connectome", as well as new technologies that will have to be developed in the course of the project. They indicated that initial studies might be done in Caenorhabditis elegans, followed by Drosophila, because of their comparatively simple neural circuits. Mid-term studies could be done in zebrafish, mice, and the Etruscan shrew, with studies ultimately to be done in primates and humans. They proposed the development of nanoparticles that could be used as voltage sensors that would detect individual action potentials, as well as nanoprobes that could serve as electrophysiological multielectrode arrays. In particular, they called for the use of wireless, noninvasive methods of neuronal activity detection, either utilizing microelectronic very-large-scale integration, or based on synthetic biology rather than microelectronics. In one such proposed method, enzymatically produced DNA would serve as a "ticker tape record" of neuronal activity, based on calcium ion-induced errors in coding by DNA polymerase. Data would be analyzed and modeled by large scale computation. A related technique proposed the use of high-throughput DNA sequencing for rapidly mapping neural connectivity.

Timeline

The timeline proposed by the Working Group in 2014 is:

• 2016–2020: technology development and validation
• 2020–2025: application of those technologies in an integrated fashion to make fundamental new discoveries about the brain

Working group

The advisory committee is:

Cornelia Bargmann, PhD (co‐chair), The Rockefeller University William Newsome, PhD (co‐chair), Stanford University David J. Anderson, PhD, California Institute of Technology Emery Brown, MD, PhD, Massachusetts Institute of Technology Karl Deisseroth, MD, PhD, Stanford University John Donoghue, PhD, Brown University Peter MacLeish, PhD, Morehouse School of Medicine Eve Marder, PhD, Brandeis University

Richard A. Normann, PhD, University of Utah Joshua Sanes, PhD, Harvard University Mark Schnitzer, PhD, Stanford University Terry Sejnowski, PhD, Salk Institute for Biological Studies David Tank, PhD, Princeton University Roger Y. Tsien, PhD, University of California, San Diego Kamil Ugurbil, PhD, University of Minnesota

Participants

As of December 2018, the BRAIN Initiative website lists the following participants and affiliates:

• National Institutes of Health (Alliance Member)
• National Science Foundation (Alliance Member)
• U.S. Food and Drug Administration (Alliance Member)
• Intelligence Advanced Research Projects Activity (IARPA) (Alliance Member)
• White House BRAIN Initiative (Alliance Affiliate)
• Defense Advanced Research Projects Agency (B.I. Participant)
• Simons Foundation (Alliance Member)
• National Photonics Initiative (B.I. Participant)
• Allen Institute for Brain Science (Alliance Member)
• Janelia/Howard Hughes Medical Institute (Alliance Affiliate)
• Neurotechnology Architecting Network (B.I. Participant)
• Pacific Northwest Neuroscience Neighborhood (B.I. Participant)
• University of California System Cal-BRAIN (B.I. Participant)
• University of Pittsburgh Brain Institute (B.I. Participant)
• Blackrock Microsystems (B.I. Participant)
• GlaxoSmithKline (B.I. Participant)
• Brain & Behavior Research Foundation (B.I. Participant)
• Boston University Center for Systems Neuroscience (B.I. Participant)
• General Electric (B.I. Participant)
• Boston Scientific (B.I. Participant)
• Carnegie Mellon University BrainHub (B.I. Participant)
• NeuroNexus (B.I. Participant)
• Medtronic (B.I. Participant)
• Pediatric Brain Foundation (B.I. Participant)
• University of Texas System UT Neuroscience (B.I. Participant)
• University of Arizona Center for Innovation in Brain Science (B.I. Participant)
• Salk Institute for Biological Studies (B.I. Participant)
• Second Sight (B.I. Participant)
• Kavli Foundation (Alliance Member)
• University of Utah Neurosciences Gateway (B.I. Participant)
• Blackrock Microsystems (B.I. Participant)
• Ripple (B.I. Participant)
• Lawrence Livermore National Laboratory (B.I. Participant)
• NeuroPace (B.I. Participant)
• Google (B.I. Participant)
• Inscopix (B.I. Participant)
• Australian National Health and Medical Research Council (B.I. Participant)
• Brain Canada Foundation (B.I. Participant)
• Denmark's Lundbeck Foundation (B.I. Participant).

Reactions

Scientists offered differing views of the plan. Neuroscientist John Donoghue said that the project would fill a gap in neuroscience research between, on the one hand, activity measurements at the level of brain regions using methods such as fMRI, and, on the other hand, measurements at the level of single cells. Psychologist Ed Vul expressed concern, however, that the initiative would divert funding from individual investigator studies. Neuroscientist Donald Stein expressed concern that it would be a mistake to begin by spending money on technological methods, before knowing exactly what would be measured. Physicist Michael Roukes argued instead that methods in nanotechnology are becoming sufficiently mature to make the time right for a brain activity map. Neuroscientist Rodolfo Llinás declared at the first Rockefeller meeting "What has happened here is magnificent, never before in neuroscience have I seen so much unity in such a glorious purpose."

The projects face great logistical challenges. Neuroscientists estimated that the project would generate 300 exabytes of data every year, presenting a significant technical barrier. Most of the available high-resolution brain activity monitors are of limited use, as they must be invasively implanted surgically by opening the skull. Parallels have been drawn to past large-scale government-led research efforts including the map of the human genome, the voyage to the moon, and the development of the atomic bomb.

Human Brain Project

From Wikipedia, the free encyclopedia

 

Human Brain Project
Type of project	Scientific research
Location	Europe
Owner	European Union
Key people	Paweł Świeboda, Director General Katrin Amunts, Scientific Research Director
Established	2013; 8 years ago
Website	www.humanbrainproject.eu

The Human Brain Project (HBP) is a large ten-year scientific research project, based on exascale supercomputers, that aims to build a collaborative ICT-based scientific research infrastructure to allow researchers across Europe to advance knowledge in the fields of neuroscience, computing, and brain-related medicine.

The Project, which started on 1 October 2013, is a European Commission Future and Emerging Technologies Flagship. The HBP is coordinated by the École Polytechnique Fédérale de Lausanne and is largely funded by the European Union. The project coordination office is in Geneva, Switzerland.

Strategic goals and organisation

The 2013 HBP Summit–the inauguration of the Project–took place in the EPFL Learning Centre in October 2013. It brought together scientists from over 100 Partner Institutions.

Fundamental to the HBP approach is to investigate the brain on different spatial and temporal scales (i.e. from the molecular to the large networks underlying higher cognitive processes, and from milliseconds to years). To achieve this goal, the HBP relies on the collaboration of scientists from diverse disciplines, including neuroscience, philosophy and computer science, to take advantage of the loop of experimental data, modelling theories and simulations. The idea is that empirical results are used to develop theories, which then foster modelling and simulations which result in predictions that are in turn verified by empirical results.

The primary objective of the HBP is to create an ICT-based research infrastructure for brain research, cognitive neuroscience and brain-inspired computing, which can be used by researchers world-wide.

The Project is divided into 12 Subprojects. Six of these develop ICT-based platforms (Subprojects 5-10), which consist of prototype hardware, software, databases, and programming interfaces. These tools are available to researchers worldwide via the HBP Collaboratory. Three Subprojects gather data on empirical neuroscience and establish theoretical foundations (Subprojects 1–4) and one is responsible for ethics and society (Subproject 12). Subproject 11 coordinates the project.

• SP1 Mouse Brain Organisation: Understanding the structure of the mouse brain, and its electrical and chemical functions
• SP2 Human Brain Organisation: Understanding the structure of the human brain, and its electrical and chemical functions
• SP3 Systems and Cognitive Neuroscience: Understanding how the brain performs its systems-level and cognitive functional activities
• SP4 Theoretical Neuroscience: Deriving high-level mathematical models to synthesize conclusions from research data
• SP5 Neuroinformatics Platform: Gathering, organising and making available brain data
• SP6 Brain Simulation Platform: Developing data-driven reconstructions of brain tissue and simulation capabilities to explore these reconstructions
• SP7 High-performance Analytics and Computing Platform: Providing the ICT capability to map the brain in unprecedented detail, construct complex models, run large simulations, and analyse large volumes of data
• SP8 Medical Informatics Platform: Developing the infrastructure to share hospital and medical research data for the purpose of understanding disease clusters and their respective disease signatures
• SP9 Neuromorphic Computing Platform: Developing and applying brain-inspired computing technology
• SP10 Neurorobotics Platform: Developing virtual and real robots and environments for testing brain simulations
• SP11 Management and Coordination: General coordination of the project
• SP12 Ethics and Society: Exploring the ethical and societal impact of HBP's work

The HBP is coordinated by the École Polytechnique Fédérale de Lausanne and involves researchers from over 117 partner institutions in 19 countries across Europe. Notable Partner Institutions include the University of Heidelberg, Forschungszentrum Jülich, and the University Hospital of Lausanne.

The scientific direction is provided by representatives from each of the HBP's Subprojects, which form the Science and Infrastructure Board (SIB). Katrin Amunts from Forschungszentrum Jülich is the Chair of the SIB. Alois Knoll from TU Munich is Vice Chair of the SIB for software. The Directorate steers the daily work of the HBP – it is led by Andreas Mortensen from EPFL.

Funding

The HBP is funded by the European Commission Directorate General for Communications Networks, Content and Technology (DG CONNECT) under the FP7 framework, an EU Research and Innovation funding programme. It was one of the two initial Future Emerging Technologies (FET) Flagship projects.

The project is split into five phases, each supplied with separate funding. The call for funding for the Project's initial two-and-a-half-year 'Ramp-Up Phase' of EUR 54 million closed in November 2013 and the results were announced in March 2014. Twenty-two projects from thirty-two organisations were selected for the initial funding of EUR 8.3 million. The Ramp-Up Phase ended on 31 March 2016. Funding is reassessed every two years using Specific Grant Agreements (SGA); the first of which began in April 2016 (ending in April 2018), and the second with a total EU funding of 88 Million Euro starting in April 2018 (ending in March 2020). The HBP's total costs are estimated at EUR 1.019 billion, of which EUR 500 million will be provided by the European Commission, EUR 500 million by national, public and private organisations, and EUR 19 million by the Core Project Ramp-Up Phase Partners.

Obstacles

One of the Project's primary hurdles is the unsystematic nature of the information collected from previous brain research. Neurological research data varies by biological organisation schemes, species studied, and by developmental stages, making it difficult to collectively use the data to replicate the brain in a model that acts as a single system.

Other obstacles include engineering problems involving power consumption, memory, and storage. For example, detailed neuron representations are very computationally expensive, and whole brain simulation is at the leading edge of our computational capability.

Implications

The Human Brain Project moved to Campus Biotech in 2014.

Technologies generated by the HBP and other similar projects offer several possibilities to other fields of research. For instance, a brain model can be used to investigate signatures of disease in the brain and the impact of certain drugs, enabling the development of better diagnosis and treatment methods. Ultimately, these technologies will likely lead to more advanced medical options available to patients at a lower cost.

In addition, detailed brain simulation requires significant computing power, leading to developments in supercomputing and energy-efficient, brain-inspired computing techniques. Computational developments can be extended into areas such as data mining, telecommunications, appliances, and other industrial uses.

The long-term ethical consequences of the Project are also considered. The Project follows a policy of Responsible Research and Innovation, and its Ethics Advisory Board is responsible for monitoring the use of human volunteers, animal subjects, and the data collected. Implications on European society, industry, and economy are investigated by the HBP Ethics and Society Programme's Foresight Lab.

Criticism

An open letter was sent on 7 July 2014 to the European Commission by 154 European researchers (750 signatures as of 3 September 2014) complaining of the HBP's overly narrow approach, and threatening to boycott the project. Central to this controversy was an internal dispute about funding for cognitive scientists who study high level brain functions, such as thought and behaviour. However, the HBP stated that there is “no question that cognition and behaviour are vital to the HBP”, explaining that cognitive neuroscience research was repositioned in the project to allow the core project to focus on building the platforms. In addition, The open letter called on the EC to “reallocate the funding currently allocated to the HBP core and partnering projects to broad neuroscience-directed funding to meet the original goals of the HBP—understanding brain function and its effect on society”. In its response, the HBP said that “while neuroscience research generates a vast amount of valuable data, there is currently no technology for sharing, organising, analysing or integrating this information, beyond papers and even databases. The HBP will provide the critical missing layer to move towards a multi-level reconstruction and simulation of the brain”. It added that “cognitive and behavioural neuroscience will become the most significant component of neuroscience in HBP over the course of the project. However, for this to happen the platforms have to be in place first”.

Peter Dayan, director of computational neuroscience at University College London, argued that the goal of a large-scale simulation of the brain is radically premature, and Geoffrey Hinton said that "the real problem with that project is they have no clue how to get a large system like that to learn". Similar concerns as to the project's methodology were raised by Robert Epstein.

The HBP has said that its members share the uncertainty surrounding large-scale simulation, but that “reconstructing and simulating the human brain is a vision, a target; the benefits will come from the technology needed to get there. That technology, developed by the HBP, will benefit all of neuroscience as well as related fields”.

In 2015 the project underwent a review process and the three-member executive committee, led by Henry Markram, was dissolved and replaced by a 22-member governing board.

According to a 2019 article, "In 2013, the European Commission awarded his initiative—the Human Brain Project (HBP)—a staggering 1 billion euro grant (worth about $1.42 billion at the time)...the people I contacted struggled to name a major contribution that the HBP has made in the past decade."

Pleiotropy

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Pleiotropy 

Simple genotype–phenotype map that only shows additive pleiotropy effects. G1, G2, and G3 are different genes that contribute to phenotypic traits P1, P2, and P3.

Pleiotropy (from Greek πλείων pleion, "more", and τρόπος tropos, "way") occurs when one gene influences two or more seemingly unrelated phenotypic traits. Such a gene that exhibits multiple phenotypic expression is called a pleiotropic gene. Mutation in a pleiotropic gene may have an effect on several traits simultaneously, due to the gene coding for a product used by a myriad of cells or different targets that have the same signaling function.

Pleiotropy can arise from several distinct but potentially overlapping mechanisms, such as gene pleiotropy, developmental pleiotropy, and selectional pleiotropy. Gene pleiotropy occurs when a gene product interacts with multiple other proteins or catalyzes multiple reactions. Developmental pleiotropy occurs when mutations have multiple effects on the resulting phenotype. Selectional pleiotropy occurs when the resulting phenotype has many effects on fitness (depending on factors such as age and gender).

An example of pleiotropy is phenylketonuria, an inherited disorder that affects the level of phenylalanine, an amino acid that can be obtained from food, in the human body. Phenylketonuria causes this amino acid to increase in amount in the body, which can be very dangerous. The disease is caused by a defect in a single gene on chromosome 12 that codes for enzyme phenylalanine hydroxylase, that affects multiple systems, such as the nervous and integumentary system. Pleiotropy not only affects humans, but also animals, such as chickens and laboratory house mice, where the mice have the "mini-muscle" allele.

Pleiotropic gene action can limit the rate of multivariate evolution when natural selection, sexual selection or artificial selection on one trait favors one allele, while selection on other traits favors a different allele. Some gene evolution is harmful to an organism. Genetic correlations and responses to selection most often exemplify pleiotropy.

History

Pleiotropic traits had been previously recognized in the scientific community but had not been experimented on until Gregor Mendel's 1866 pea plant experiment. Mendel recognized that certain pea plant traits (seed coat color, flower color, and axial spots) seemed to be inherited together; however, their correlation to a single gene has never been proven. The term "pleiotropie" was first coined by Ludwig Plate in his Festschrift, which was published in 1910. He originally defined pleiotropy as occurring when "several characteristics are dependent upon ... [inheritance]; these characteristics will then always appear together and may thus appear correlated". This definition is still used today.

After Plate's definition, Hans Gruneberg was the first to study the mechanisms of pleiotropy. In 1938 Gruneberg published an article dividing pleiotropy into two distinct types: "genuine" and "spurious" pleiotropy. "Genuine" pleiotropy is when two distinct primary products arise from one locus. "Spurious" pleiotropy, on the other hand, is either when one primary product is utilized in different ways or when one primary product initiates a cascade of events with different phenotypic consequences. Gruneberg came to these distinctions after experimenting on rats with skeletal mutations. He recognized that "spurious" pleiotropy was present in the mutation, while "genuine" pleiotropy was not, thus partially invalidating his own original theory. Through subsequent research, it has been established that Gruneberg's definition of "spurious" pleiotropy is what we now identify simply as "pleiotropy".

In 1941 American geneticists George Beadle and Edward Tatum further invalidated Gruneberg's definition of "genuine" pleiotropy, advocating instead for the "one gene-one enzyme" hypothesis that was originally introduced by French biologist Lucien Cuénot in 1903. This hypothesis shifted future research regarding pleiotropy towards how a single gene can produce various phenotypes.

In the mid-1950s Richard Goldschmidt and Ernst Hadorn, through separate individual research, reinforced the faultiness of "genuine" pleiotropy. A few years later, Hadorn partitioned pleiotropy into a "mosaic" model (which states that one locus directly affects two phenotypic traits) and a "relational" model (which is analogous to "spurious" pleiotropy). These terms are no longer in use but have contributed to the current understanding of pleiotropy.

By accepting the one gene-one enzyme hypothesis, scientists instead focused on how uncoupled phenotypic traits can be affected by genetic recombination and mutations, applying it to populations and evolution. This view of pleiotropy, "universal pleiotropy", defined as locus mutations being capable of affecting essentially all traits, was first implied by Ronald Fisher's Geometric Model in 1930. This mathematical model illustrates how evolutionary fitness depends on the independence of phenotypic variation from random changes (that is, mutations). It theorizes that an increasing phenotypic independence corresponds to a decrease in the likelihood that a given mutation will result in an increase in fitness. Expanding on Fisher's work, Sewall Wright provided more evidence in his 1968 book Evolution and the Genetics of Populations: Genetic and Biometric Foundations by using molecular genetics to support the idea of "universal pleiotropy". The concepts of these various studies on evolution have seeded numerous other research projects relating to individual fitness.

In 1957 evolutionary biologist George C. Williams theorized that antagonistic effects will be exhibited during an organism's life cycle if it is closely linked and pleiotropic. Natural selection favors genes that are more beneficial prior to reproduction than after (leading to an increase in reproductive success). Knowing this, Williams argued that if only close linkage was present, then beneficial traits will occur both before and after reproduction due to natural selection. This, however, is not observed in nature, and thus antagonistic pleiotropy contributes to the slow deterioration with age (senescence).

Mechanism

Pleiotropy describes the genetic effect of a single gene on multiple phenotypic traits. The underlying mechanism is genes that code for a product that is either used by various cells or has a cascade-like signaling function that affects various targets.

Polygenic Traits

Most genetic traits are polygenic in nature: controlled by many genetic variants, each of small effect. These genetic variants can reside in protein coding or non-coding regions of the genome. In this context pleiotropy refers to the influence that a specific genetic variant, e.g., a Single Nucleotide Polymorphism or SNP, has on two or more distinct traits.

Genome-wide association studies (GWAS) and machine learning analysis of large genomic datasets have led to the construction of SNP based polygenic predictors for human traits such as height, bone density, and many disease risks. Similar predictors exist for plant and animal species and are used in agricultural breeding.

One measure of pleiotropy is the fraction of genetic variance that is common between two distinct complex human traits: e.g., height vs bone density, breast cancer vs heart attack risk, or diabetes vs hypothyroidism risk. This has been calculated for hundreds of pairs of traits, with results shown in the Table. In most cases examined the genomic regions controlling each trait are largely disjoint, with only modest overlap.

Pleiotropy seems limited for many traits in humans since the SNP overlap, as measured by variance accounted for, between many polygenic predictors is small.

Thus, at least for complex human traits so far examined, pleiotropy is limited in extent.

Models for the origin

One basic model of pleiotropy's origin describes a single gene locus to the expression of a certain trait. The locus affects the expressed trait only through changing the expression of other loci. Over time, that locus would affect two traits by interacting with a second locus. Directional selection for both traits during the same time period would increase the positive correlation between the traits, while selection on only one trait would decrease the positive correlation between the two traits. Eventually, traits that underwent directional selection simultaneously were linked by a single gene, resulting in pleiotropy.

Other more complex models compensate for some of the basic model's oversights, such as multiple traits or assumptions about how the loci affect the traits. They also propose the idea that pleiotropy increases the phenotypic variation of both traits since a single mutation on a gene would have twice the effect.

Evolution

Pleiotropy can have an effect on the evolutionary rate of genes and allele frequencies. Traditionally, models of pleiotropy have predicted that evolutionary rate of genes is related negatively with pleiotropy – as the number of traits of an organism increases, the evolutionary rates of genes in the organism's population decrease. However, this relationship has not been clearly found in empirical studies.

In mating, for many animals the signals and receptors of sexual communication may have evolved simultaneously as the expression of a single gene, instead of the result of selection on two independent genes, one that affects the signaling trait and one that affects the receptor trait. In such a case, pleiotropy would facilitate mating and survival. However, pleiotropy can act negatively as well. A study on seed beetles found that intralocus sexual conflict arises when selection for certain alleles of a gene that are beneficial for one sex causes expression of potentially harmful traits by the same gene in the other sex, especially if the gene is located on an autosomal chromosome.

Pleiotropic genes act as an arbitrating force in speciation. William R. Rice and Ellen E. Hostert (1993) conclude that the observed prezygotic isolation in their studies is a product of pleiotropy's balancing role in indirect selection. By imitating the traits of all-infertile hybridized species, they noticed that the fertilization of eggs was prevented in all eight of their separate studies, a likely effect of pleiotropic genes on speciation. Likewise, pleiotropic gene's stabilizing selection allows for the allele frequency to be altered.

Studies on fungal evolutionary genomics have shown pleiotropic traits that simultaneously affect adaptation and reproductive isolation, converting adaptations directly to speciation. A particularly telling case of this effect is host specificity in pathogenic ascomycetes and specifically, in venturia, the fungus responsible for apple scab. These parasitic fungi each adapts to a host, and are only able to mate within a shared host after obtaining resources. Since a single toxin gene or virulence allele can grant the ability to colonize the host, adaptation and reproductive isolation are instantly facilitated, and in turn, pleiotropically causes adaptive speciation. The studies on fungal evolutionary genomics will further elucidate the earliest stages of divergence as a result of gene flow, and provide insight into pleiotropically induced adaptive divergence in other eukaryotes.

Antagonistic pleiotropy

Main article: Antagonistic pleiotropy hypothesis

Sometimes, a pleiotropic gene may be both harmful and beneficial to an organism, which is referred to as antagonistic pleiotropy. This may occur when the trait is beneficial for the organism's early life, but not its late life. Such "trade-offs" are possible since natural selection affects traits expressed earlier in life, when most organisms are most fertile, more than traits expressed later in life.

This idea is central to the antagonistic pleiotropy hypothesis, which was first developed by G. C. Williams in 1957. Williams suggested that some genes responsible for increased fitness in the younger, fertile organism contribute to decreased fitness later in life, which may give an evolutionary explanation for senescence. An example is the p53 gene, which suppresses cancer but also suppresses stem cells, which replenish worn-out tissue.

Unfortunately, the process of antagonistic pleiotropy may result in an altered evolutionary path with delayed adaptation, in addition to effectively cutting the overall benefit of any alleles by roughly half. However, antagonistic pleiotropy also lends greater evolutionary "staying power" to genes controlling beneficial traits, since an organism with a mutation to those genes would have a decreased chance of successfully reproducing, as multiple traits would be affected, potentially for the worse.

Sickle cell anemia is a classic example of the mixed benefit given by the staying power of pleiotropic genes, as the mutation to Hb-S provides the fitness benefit of malaria resistance to heterozygotes, while homozygotes have significantly lowered life expectancy. Since both of these states are linked to the same mutated gene, large populations today are susceptible to sickle cell despite it being a fitness-impairing genetic disorder.

Examples

Peacock with albinism

Albinism

Main article: Albinism

Albinism is the mutation of the TYR gene, also termed tyrosinase. This mutation causes the most common form of albinism. The mutation alters the production of melanin, thereby affecting melanin-related and other dependent traits throughout the organism. Melanin is a substance made by the body that is used to absorb light and provides coloration to the skin. Indications of albinism are the absence of color in an organism's eyes, hair, and skin, due to the lack of melanin. Some forms of albinism are also known to have symptoms that manifest themselves through rapid-eye movement, light sensitivity, and strabismus.

Autism and schizophrenia

Main articles: Autism and Schizophrenia

Pleiotropy in genes has been linked between certain psychiatric disorders as well. Deletion in the 22q11.2 region of chromosome 22 has been associated with schizophrenia and autism. Schizophrenia and autism are linked to the same gene deletion but manifest very differently from each other. The resulting phenotype depends on the stage of life at which the individual develops the disorder. Childhood manifestation of the gene deletion is typically associated with autism, while adolescent and later expression of the gene deletion often manifests in schizophrenia or other psychotic disorders. Though the disorders are linked by genetics, there is no increased risk found for adult schizophrenia in patients who experienced autism in childhood.

A 2013 study also genetically linked five psychiatric disorders, including schizophrenia and autism. The link was a single nucleotide polymorphism of two genes involved in calcium channel signaling with neurons. One of these genes, CACNA1C, has been found to influence cognition. It has been associated with autism, as well as linked in studies to schizophrenia and bipolar disorder. These particular studies show clustering of these diseases within patients themselves or families. The estimated heritability of schizophrenia is 70% to 90%, therefore the pleiotropy of genes is crucial since it causes an increased risk for certain psychotic disorders and can aid psychiatric diagnosis.

Phenylketonuria (PKU)

Main article: Phenylketonuria

The blood of a two-week-old infant is collected for a PKU screening.

A common example of pleiotropy is the human disease phenylketonuria (PKU). This disease causes mental retardation and reduced hair and skin pigmentation, and can be caused by any of a large number of mutations in the single gene on chromosome 12 that codes for the enzyme phenylalanine hydroxylase, which converts the amino acid phenylalanine to tyrosine. Depending on the mutation involved, this conversion is reduced or ceases entirely. Unconverted phenylalanine builds up in the bloodstream and can lead to levels that are toxic to the developing nervous system of newborn and infant children. The most dangerous form of this is called classic PKU, which is common in infants. The baby seems normal at first but actually incurs permanent intellectual disability. This can cause symptoms such as mental retardation, abnormal gait and posture, and delayed growth. Because tyrosine is used by the body to make melanin (a component of the pigment found in the hair and skin), failure to convert normal levels of phenylalanine to tyrosine can lead to fair hair and skin. The frequency of this disease varies greatly. Specifically, in the United States, PKU is found at a rate of nearly 1 in 10,000 births. Due to newborn screening, doctors are able to detect PKU in a baby sooner. This allows them to start treatment early, preventing the baby from suffering from the severe effects of PKU. PKU is caused by a mutation in the PAH gene, whose role is to instruct the body on how to make phenylalanine hydroxylase. Phenylalanine hydroxylase is what converts the phenylalanine, taken in through diet, into other things that the body can use. The mutation often decreases the effectiveness or rate at which the hydroxylase breaks down the phenylalanine. This is what causes the phenylalanine to build up in the body. The way to treat PKU is to manage one's diet. Phenylalanine is ingested through food, so a diet should decrease types of foods that have high amounts of phenylalanine. Foods with high levels of protein must be avoided. These include breast milk, eggs, chicken, beef, pork, fish, nuts, and other foods. A special PKU formula can be obtained in order for the body to have protein.

Sickle cell anemia

Main article: Sickle-cell disease

Photomicrograph of normal-shaped and sickle-shape red blood cells from a patient with sickle cell disease

Sickle cell anemia is a genetic disease that causes deformed red blood cells with a rigid, crescent shape instead of the normal flexible, round shape. It is caused by a change in one nucleotide, a point mutation in the HBB gene. The HBB gene encodes information to make the beta-globin subunit of hemoglobin, which is the protein red blood cells use to carry oxygen throughout the body. Sickle cell anemia occurs when the HBB gene mutation causes both beta-globin subunits of hemoglobin to change into hemoglobin S (HbS).

Sickle cell anemia is a pleiotropic disease because the expression of a single mutated HBB gene produces numerous consequences throughout the body. The mutated hemoglobin forms polymers and clumps together causing the deoxygenated sickle red blood cells to assume the disfigured sickle shape. As a result, the cells are inflexible and cannot easily flow through blood vessels, increasing the risk of blood clots and possibly depriving vital organs of oxygen. Some complications associated with sickle cell anemia include pain, damaged organs, strokes, high blood pressure, and loss of vision. Sickle red blood cells also have a shortened lifespan and die prematurely.

Marfan syndrome

Main article: Marfan syndrome

Patient with Marfan Syndrome

Marfan syndrome (MFS) is an autosomal dominant disorder which affects 1 in 5–10,000 people. MFS arises from a mutation in the FBN1 gene, which encodes for the glycoprotein fibrillin-1, a major constituent of extracellular microfibrils which form connective tissues. Over 1,000 different mutations in FBN1 have been found to result in abnormal function of fibrillin, which consequently relates to connective tissues elongating progressively and weakening. Because these fibers are found in tissues throughout the body, mutations in this gene can have a widespread effect on certain systems, including the skeletal, cardiovascular, and nervous system, as well as the eyes and lungs.

Without medical intervention, prognosis of Marfan syndrome can range from moderate to life-threatening, with 90% of known causes of death in diagnosed patients relating to cardiovascular complications and congestive cardiac failure. Other characteristics of MFS include an increased arm span and decreased upper to lower body ratio.

"Mini-muscle" allele

A gene recently discovered in laboratory house mice, termed "mini-muscle", causes, when mutated, a 50% reduction in hindlimb muscle mass as its primary effect (the phenotypic effect by which it was originally identified). In addition to smaller hindlimb muscle mass, the mutant mice exhibit lower heart rates during physical activity, and a higher endurance. Mini Muscle Mice also exhibit larger kidneys and livers. All of these morphological deviations influence the behavior and metabolism of the mouse. For example, mice with the Mini Muscle mutation were observed to have a higher per-gram aerobic capacity. The mini-muscle allele shows a mendelian recessive behavior. The mutation is a single nucleotide polymorphism (SNP) in an intron of the myosin heavy polypeptide 4 gene.

DNA repair proteins

DNA repair pathways that repair damage to cellular DNA use many different proteins. These proteins often have other functions in addition to DNA repair. In humans, defects in some of these multifunctional proteins can cause widely differing clinical phenotypes. As an example, mutations in the XPB gene that encodes the largest subunit of the basal Transcription factor II H have several pleiotropic effects. XPB mutations are known to be deficient in nucleotide excision repair of DNA and in the quite separate process of gene transcription. In humans, XPB mutations can give rise to the cancer-prone disorder xeroderma pigmentosum or the noncancer-prone multisystem disorder trichothiodystrophy. Another example in humans is the ERCC6 gene, which encodes a protein that mediates DNA repair, transcription, and other cellular processes throughout the body. Mutations in ERCC6 are associated with disorders of the eye (retinal dystrophy), heart (cardiac arrhythmias), and immune system (lymphocyte immunodeficiency).

Chickens

Chicken exhibiting the frizzle feather trait

Chickens exhibit various traits affected by pleiotropic genes. Some chickens exhibit frizzle feather trait, where their feathers all curl outward and upward rather than lying flat against the body. Frizzle feather was found to stem from a deletion in the genomic region coding for α-Keratin. This gene seems to pleiotropically lead to other abnormalities like increased metabolism, higher food consumption, accelerated heart rate, and delayed sexual maturity.

Domesticated chickens underwent a rapid selection process that led to unrelated phenotypes having high correlations, suggesting pleiotropic, or at least close linkage, effects between comb mass and physiological structures related to reproductive abilities. Both males and females with larger combs have higher bone density and strength, which allows females to deposit more calcium into eggshells. This linkage is further evidenced by the fact that two of the genes, HAO1 and BMP2, affecting medullary bone (the part of the bone that transfers calcium into developing eggshells) are located at the same locus as the gene affecting comb mass. HAO1 and BMP2 also display pleiotropic effects with commonly desired domestic chicken behavior; those chickens who express higher levels of these two genes in bone tissue produce more eggs and display less egg incubation behavior.

Atavism

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Atavism 

Early embryos of various species display some ancestral features, like the tail on this human embryo. These features normally disappear in later development, but it may not happen if the animal has an atavism.

In biology, an atavism is a modification of a biological structure whereby an ancestral genetic trait reappears after having been lost through evolutionary change in previous generations. Atavisms can occur in several ways; one of which is when genes for previously existing phenotypic features are preserved in DNA, and these become expressed through a mutation that either knocks out the dominant genes for the new traits or makes the old traits dominate the new one. A number of traits can vary as a result of shortening of the fetal development of a trait (neoteny) or by prolongation of the same. In such a case, a shift in the time a trait is allowed to develop before it is fixed can bring forth an ancestral phenotype. Atavisms are often seen as evidence of evolution.

In social sciences, atavism is the tendency of reversion. For example, people in the modern era reverting to the ways of thinking and acting of a former time.

The word atavism is derived from the Latin atavus—a great-great-great-grandfather or, more generally, an ancestor.

Biology

Evolutionarily traits that have disappeared phenotypically do not necessarily disappear from an organism's DNA. The gene sequence often remains, but is inactive. Such an unused gene may remain in the genome for many generations. As long as the gene remains intact, a fault in the genetic control suppressing the gene can lead to it being expressed again. Sometimes, the expression of dormant genes can be induced by artificial stimulation.

Atavisms have been observed in humans, such as with infants born with vestigial tails (called a "coccygeal process", "coccygeal projection", or "caudal appendage"). Atavism can also be seen in humans who possess large teeth, like those of other primates. In addition, a case of "snake heart", the presence of "coronary circulation and myocardial architecture [that closely] resemble those of the reptilian heart", has also been reported in medical literature. Atavism has also recently been induced in avian dinosaur (bird) fetuses to express dormant ancestral non-avian dinosaur (non-bird) features, including teeth.

Other examples of observed atavisms include:

• Hind limbs in cetaceans.
• Extra toes of the modern horse.
• Reappearance of limbs in limbless vertebrates.
• Re-evolution of sexuality from parthenogenesis in oribatid mites.
• Teeth in avian dinosaurs (birds).
• Dewclaws in dogs.
• Reappearance of prothoracic wings in insects.
• Reappearance of wings on wingless stick insects and leaf insects and earwigs.
• Atavistic muscles in several birds and mammals such as the beagle and the jerboa.
• Extra toes in guinea pigs.
• Reemergence of sexual reproduction in the flowering plant Hieracium pilosella and the Crotoniidae family of mites.
• Webbed feet in adult axolotls.
• Human tails (not pseudo-tails) and supernumerary nipples in humans (and other primates).
• Color blindness in humans.

Culture

Atavism is a term in Joseph Schumpeter's explanation of World War I in twentieth-century liberal Europe. He defends the liberal international relations theory that an international society built on commerce will avoid war because of war's destructiveness and comparative cost. His reason for World War I is termed "atavism", in which he asserts that senescent governments in Europe (those of the German Empire, Russian Empire, Ottoman Empire, and Austro-Hungarian Empire) pulled the liberal Europe into war, and that the liberal regimes of the other continental powers did not cause it. He used this idea to say that liberalism and commerce would continue to have a soothing effect in international relations, and that war would not arise between nations which are connected by commercial ties. This latter idea is very similar to the later Golden Arches theory.

University of London professor Guy Standing has identified three distinct sub-groups of the precariat, one of which he refers to as "atavists", who long for what they see as a lost past.

Social Darwinism

During the interval between the acceptance of evolution in the mid-1800s and the rise of the modern understanding of genetics in the early 1900s, atavism was used to account for the reappearance in an individual of a trait after several generations of absence—often called a "throw-back". The idea that atavisms could be made to accumulate by selective breeding, or breeding back, led to breeds such as the Heck cattle. This had been bred from ancient landraces with selected primitive traits, in an attempt of "reviving" the aurochs, an extinct species of wild cattle. The same notions of atavisms were used by social Darwinists, who claimed that inferior races displayed atavistic traits, and represented more primitive traits than other races.^{[citation needed]} Both atavism's and Ernst Haeckel's recapitulation theory are related to evolutionary progress, as development towards a greater complexity and a superior ability.

In addition, the concept of atavism as part of an individualistic explanation of the causes of criminal deviance was popularised by the Italian criminologist Cesare Lombroso in the 1870s. He attempted to identify physical characteristics common to criminals and labeled those he found as atavistic, 'throw-back' traits that determined 'primitive' criminal behavior. His statistical evidence and the closely related idea of eugenics have long since been abandoned by the scientific community, but the concept that physical traits may affect the likelihood of criminal or unethical behavior in a person still has some scientific support.