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Thursday, April 8, 2021

Silent Spring

From Wikipedia, the free encyclopedia
 
Silent Spring
SilentSpring.jpg
Cover of the first edition
AuthorRachel Carson
CountryUnited States
LanguageEnglish
SubjectsPesticides, ecology, environmentalism
PublishedSeptember 27, 1962 (Houghton Mifflin)
Media typePrint (Hardcover and Paperback)

Silent Spring is an environmental science book by Rachel Carson. The book was published on September 27, 1962, documenting the adverse environmental effects caused by the indiscriminate use of pesticides. Carson accused the chemical industry of spreading disinformation, and public officials of accepting the industry's marketing claims unquestioningly.

Starting in the late 1950s, prior to the book's publication, Carson had focused her attention on environmental conservation, especially environmental problems that she believed were caused by synthetic pesticides. The result of her research was Silent Spring, which brought environmental concerns to the American public. The book was met with fierce opposition by chemical companies, but, owing to public opinion, it brought about numerous changes. It spurred a reversal in the United States' national pesticide policy, led to a nationwide ban on DDT for agricultural uses, and helped to inspire an environmental movement that led to the creation of the U.S. Environmental Protection Agency.

In 1996, a follow-up book, Beyond Silent Spring, co-written by H.F. van Emden and David Peakall, was published. In 2006, Silent Spring was named one of the 25 greatest science books of all time by the editors of Discover magazine.

Research and writing

Rachel Carson, 1940
Fish and Wildlife Service employee photo

In the mid-1940s, Carson became concerned about the use of synthetic pesticides, many of which had been developed through the military funding of science after World War II. The United States Department of Agriculture's 1957 fire ant eradication program, which involved aerial spraying of DDT and other pesticides mixed with fuel oil and included the spraying of private land, prompted Carson to devote her research, and her next book, to pesticides and environmental poisons. Landowners in Long Island filed a suit to have the spraying stopped, and many in affected regions followed the case closely. Though the suit was lost, the Supreme Court granted petitioners the right to gain injunctions against potential environmental damage in the future, laying the basis for later environmental actions.

The impetus for Silent Spring was a letter written in January 1958 by Carson's friend, Olga Owens Huckins, to The Boston Herald, describing the death of birds around her property resulting from the aerial spraying of DDT to kill mosquitoes, a copy of which Huckins sent to Carson. Carson later wrote that this letter prompted her to study the environmental problems caused by chemical pesticides.

The Audubon Naturalist Society actively opposed chemical spraying programs and recruited Carson to help publicize the U.S. government's spraying practices and related research. Carson began the four-year project of Silent Spring by gathering examples of environmental damage attributed to DDT. She tried to enlist essayist E. B. White and a number of journalists and scientists to her cause. By 1958, Carson had arranged a book deal, with plans to co-write with Newsweek science journalist Edwin Diamond. However, when The New Yorker commissioned a long and well-paid article on the topic from Carson, she began considering writing more than the introduction and conclusion as planned; soon it became a solo project. Diamond would later write one of the harshest critiques of Silent Spring.

As her research progressed, Carson found a sizable community of scientists who were documenting the physiological and environmental effects of pesticides. She took advantage of her personal connections with many government scientists, who supplied her with confidential information on the subject. From reading the scientific literature and interviewing scientists, Carson found two scientific camps: those who dismissed the possible danger of pesticide spraying barring conclusive proof, and those who were open to the possibility of harm and, willing to consider alternative methods, such as biological pest control.

Fire Ants on Trial - public service film produced by the USDA

By 1959, the USDA's Agricultural Research Service responded to the criticism by Carson and others with a public service film, Fire Ants on Trial; Carson called it "flagrant propaganda" that ignored the dangers that spraying pesticides posed to humans and wildlife. That spring, Carson wrote a letter, published in The Washington Post, that attributed the recent decline in bird populations—in her words, the "silencing of birds"—to pesticide overuse. The same year, the 1957, 1958, and 1959 crops of U.S. cranberries were found to contain high levels of the herbicide aminotriazole and the sale of all cranberry products was halted. Carson attended the ensuing FDA hearings on revising pesticide regulations; she was discouraged by the aggressive tactics of the chemical industry representatives, which included expert testimony that was firmly contradicted by the bulk of the scientific literature she had been studying. She also wondered about the possible "financial inducements behind certain pesticide programs".

Research at the National Library of Medicine of the National Institutes of Health brought Carson into contact with medical researchers investigating the gamut of cancer-causing chemicals. Of particular significance was the work of National Cancer Institute researcher and founding director of the environmental cancer section Wilhelm Hueper, who classified many pesticides as carcinogens. Carson and her research assistant Jeanne Davis, with the help of NIH librarian Dorothy Algire, found evidence to support the pesticide-cancer connection; to Carson the evidence for the toxicity of a wide array of synthetic pesticides was clear-cut, though such conclusions were very controversial beyond the small community of scientists studying pesticide carcinogenesis.

By 1960, Carson had sufficient research material and the writing was progressing rapidly. She had investigated hundreds of individual incidents of pesticide exposure and the resulting human sickness and ecological damage. In January 1960, she suffered an illness which kept her bedridden for weeks, delaying the book. As she was nearing full recovery in March, she discovered cysts in her left breast, requiring a mastectomy. By December that year, Carson discovered that she had breast cancer, which had metastasized. Her research was also delayed by revision work for a new edition of The Sea Around Us, and by a collaborative photo essay with Erich Hartmann. Most of the research and writing was done by the fall of 1960, except for a discussion of recent research on biological controls and investigations of some new pesticides. However, further health troubles delayed the final revisions in 1961 and early 1962.

Its title was inspired by a poem by John Keats, "La Belle Dame sans Merci", which contained the lines "The sedge is wither'd from the lake, And no birds sing." "Silent Spring" was initially suggested as a title for the chapter on birds. By August 1961, Carson agreed to the suggestion of her literary agent Marie Rodell: Silent Spring would be a metaphorical title for the entire book—suggesting a bleak future for the whole natural world—rather than a literal chapter title about the absence of birdsong. With Carson's approval, editor Paul Brooks at Houghton Mifflin arranged for illustrations by Louis and Lois Darling, who also designed the cover. The final writing was the first chapter, "A Fable for Tomorrow", which was intended to provide a gentle introduction to a serious topic. By mid-1962, Brooks and Carson had largely finished the editing and were planning to promote the book by sending the manuscript to select individuals for final suggestions. In Silent Spring, Carson relied on evidence from two New York state organic farmers, Marjorie Spock and Mary Richards, and that of biodynamic farming advocate Ehrenfried Pfeiffer in developing her case against DDT.

Content

The overarching theme of Silent Spring is the powerful—and often negative—effect humans have on the natural world. Carson's main argument is that pesticides have detrimental effects on the environment; she says these are more properly termed "biocides" because their effects are rarely limited to solely targeting pests. DDT is a prime example, but other synthetic pesticides—many of which are subject to bioaccumulation—are scrutinized. Carson accuses the chemical industry of intentionally spreading disinformation and public officials of accepting industry claims uncritically. Most of the book is devoted to pesticides' effects on natural ecosystems, but four chapters detail cases of human pesticide poisoning, cancer, and other illnesses attributed to pesticides. About DDT and cancer, Carson says only:

In laboratory tests on animal subjects, DDT has produced suspicious liver tumors. Scientists of the Food and Drug Administration who reported the discovery of these tumors were uncertain how to classify them, but felt there was some "justification for considering them low grade hepatic cell carcinomas." Dr. Hueper [author of Occupational Tumors and Allied Diseases] now gives DDT the definite rating of a "chemical carcinogen."

Carson predicts increased consequences in the future, especially since targeted pests may develop resistance to pesticides and weakened ecosystems fall prey to unanticipated invasive species. The book closes with a call for a biotic approach to pest control as an alternative to chemical pesticides.

Carson never called for an outright ban on DDT. She said in Silent Spring that even if DDT and other insecticides had no environmental side effects, their indiscriminate overuse was counterproductive because it would create insect resistance to pesticides, making them useless in eliminating the target insect populations:

No responsible person contends that insect-borne disease should be ignored. The question that has now urgently presented itself is whether it is either wise or responsible to attack the problem by methods that are rapidly making it worse. The world has heard much of the triumphant war against disease through the control of insect vectors of infection, but it has heard little of the other side of the story—the defeats, the short-lived triumphs that now strongly support the alarming view that the insect enemy has been made actually stronger by our efforts. Even worse, we may have destroyed our very means of fighting.

Carson also said that "Malaria programmes are threatened by resistance among mosquitoes", and quoted the advice given by the director of Holland's Plant Protection Service: "Practical advice should be 'Spray as little as you possibly can' rather than 'Spray to the limit of your capacity'. Pressure on the pest population should always be as slight as possible."

Promotion and reception

Carson and the others involved with publication of Silent Spring expected fierce criticism and were concerned about the possibility of being sued for libel. Carson was undergoing radiation therapy for her cancer and expected to have little energy to defend her work and respond to critics. In preparation for the anticipated attacks, Carson and her agent attempted to amass prominent supporters before the book's release.

Most of the book's scientific chapters were reviewed by scientists with relevant expertise, among whom Carson found strong support. Carson attended the White House Conference on Conservation in May 1962; Houghton Mifflin distributed proof copies of Silent Spring to many of the delegates and promoted the upcoming serialization in The New Yorker. Carson also sent a proof copy to Supreme Court Associate Justice William O. Douglas, a long-time environmental advocate who had argued against the court's rejection of the Long Island pesticide spraying case and had provided Carson with some of the material included in her chapter on herbicides.

Though Silent Spring had generated a fairly high level of interest based on pre-publication promotion, this became more intense with its serialization, which began in the June 16, 1962, issue. This brought the book to the attention of the chemical industry and its lobbyists, as well as the American public. Around that time, Carson learned that Silent Spring had been selected as the Book-of-the-Month for October; she said this would "carry it to farms and hamlets all over that country that don't know what a bookstore looks like—much less The New Yorker." Other publicity included a positive editorial in The New York Times and excerpts of the serialized version were published in Audubon Magazine. There was another round of publicity in July and August as chemical companies responded. The story of the birth defect-causing drug thalidomide had broken just before the book's publication, inviting comparisons between Carson and Frances Oldham Kelsey, the Food and Drug Administration reviewer who had blocked the drug's sale in the United States.

The Book-of-the-Month Club edition of Silent Spring, including an endorsement by Justice Douglas, had a first print run of 150,000 copies, two-and-a-half times the combined size of the two conventional printings of the initial release.

In the weeks before the September 27, 1962, publication, there was strong opposition to Silent Spring from the chemical industry. DuPont, a major manufacturer of DDT and 2,4-D, and Velsicol Chemical Company, the only manufacturer of chlordane and heptachlor, were among the first to respond. DuPont compiled an extensive report on the book's press coverage and estimated impact on public opinion. Velsicol threatened legal action against Houghton Mifflin, and The New Yorker and Audubon Magazine unless their planned Silent Spring features were canceled. Chemical industry representatives and lobbyists lodged a range of non-specific complaints, some anonymously. Chemical companies and associated organizations produced brochures and articles promoting and defending pesticide use. However, Carson's and the publishers' lawyers were confident in the vetting process Silent Spring had undergone. The magazine and book publications proceeded as planned, as did the large Book-of-the-Month printing, which included a pamphlet by William O. Douglas endorsing the book.

American Cyanamid biochemist Robert White-Stevens and former Cyanamid chemist Thomas Jukes were among the most aggressive critics, especially of Carson's analysis of DDT. According to White-Stevens, "If man were to follow the teachings of Miss Carson, we would return to the Dark Ages, and the insects and diseases and vermin would once again inherit the earth". Others attacked Carson's personal character and scientific credentials, her training being in marine biology rather than biochemistry. White-Stevens called her "a fanatic defender of the cult of the balance of nature", while former U.S. Secretary of Agriculture Ezra Taft Benson in a letter to former President Dwight D. Eisenhower reportedly said that because she was unmarried despite being physically attractive, she was "probably a Communist".

Monsanto published 5,000 copies of a parody called "The Desolate Year" (1962) which projected a world of famine and disease caused by banning pesticides.

Many critics repeatedly said Carson was calling for the elimination of all pesticides, but she had made it clear she was not advocating this but was instead encouraging responsible and carefully managed use with an awareness of the chemicals' impact on ecosystems. She concludes her section on DDT in Silent Spring with advice for spraying as little as possible to limit the development of resistance. Mark Hamilton Lytle writes, Carson "quite self-consciously decided to write a book calling into question the paradigm of scientific progress that defined postwar American culture".

The academic community—including prominent defenders such as H. J. Muller, Loren Eiseley, Clarence Cottam and Frank Egler—mostly backed the book's scientific claims and public opinion backed Carson's text. The chemical industry campaign was counterproductive because the controversy increased public awareness of the potential dangers of pesticides, an early example of the Streisand Effect . Pesticide use became a major public issue after a CBS Reports television special, The Silent Spring of Rachel Carson, which was broadcast on April 3, 1963. The program included segments of Carson reading from Silent Spring and interviews with other experts, mostly critics including White-Stevens. According to biographer Linda Lear, "in juxtaposition to the wild-eyed, loud-voiced Dr. Robert White-Stevens in white lab coat, Carson appeared anything but the hysterical alarmist that her critics contended". Reactions from the estimated audience of ten to fifteen million were overwhelmingly positive and the program spurred a congressional review of pesticide hazards and the public release of a pesticide report by the President's Science Advisory Committee. Within a year of publication, attacks on the book and on Carson had lost momentum.

In one of her last public appearances, Carson testified before President John F. Kennedy's Science Advisory Committee, which issued its report on May 15, 1963, largely backing Carson's scientific claims. Following the report's release, Carson also testified before a U.S. Senate subcommittee to make policy recommendations. Though Carson received hundreds of other speaking invitations, she was unable to accept most of them because her health was steadily declining, with only brief periods of remission. She spoke as much as she could, and appeared on The Today Show and gave speeches at several dinners held in her honor. In late 1963, she received a flurry of awards and honors: the Audubon Medal from the National Audubon Society, the Cullum Geographical Medal from the American Geographical Society, and induction into the American Academy of Arts and Letters. Of Carson, Maria Popova wrote, "Her lyrical writing rendered her not a mere translator of the natural world, but an alchemist transmuting the steel of science into the gold of wonder." 

Translations

The book was translated into German (under the title Der stumme Frühling), with the first German edition appearing in 1963, followed by a number of later editions.

It was translated into French (as Printemps silencieux), with the first French edition also appearing in 1963.

In 1964 the book was translated into Dutch (as "Dode lente"), according to Worldcat.org the second edition was published in 1962.

In 1965 Silent Spring was published in the USSR in Russian (under the title Безмолвная весна).

The book's Italian title is Primavera silenziosa and the Spanish title is Primavera silenciosa.

Impact

Grassroots environmentalism and the EPA

Carson's work had a powerful impact on the environmental movement. Silent Spring became a rallying point for the new social movement in the 1960s. According to environmental engineer and Carson scholar H. Patricia Hynes, "Silent Spring altered the balance of power in the world. No one since would be able to sell pollution as the necessary underside of progress so easily or uncritically." Carson's work and the activism it inspired are partly responsible for the deep ecology movement and the strength of the grassroots environmental movement since the 1960s. It was also influential on the rise of ecofeminism and on many feminist scientists. Carson's most direct legacy in the environmental movement was the campaign to ban the use of DDT in the United States, and related efforts to ban or limit its use throughout the world. The 1967 formation of the Environmental Defense Fund was the first major milestone in the campaign against DDT. The organization brought lawsuits against the government to "establish a citizen's right to a clean environment", and the arguments against DDT largely mirrored Carson's. By 1972, the Environmental Defense Fund and other activist groups had succeeded in securing a phase-out of DDT use in the United States, except in emergency cases.

The creation of the Environmental Protection Agency by the Nixon Administration in 1970 addressed another concern that Carson had written about. Until then, the USDA was responsible both for regulating pesticides and promoting the concerns of the agriculture industry; Carson saw this as a conflict of interest, since the agency was not responsible for effects on wildlife or other environmental concerns beyond farm policy. Fifteen years after its creation, one journalist described the EPA as "the extended shadow of Silent Spring". Much of the agency's early work, such as enforcement of the 1972 Federal Insecticide, Fungicide, and Rodenticide Act, was directly related to Carson's work. Contrary to the position of the pesticide industry, the DDT phase-out action taken by the EPA (led by William Ruckelshaus) implied that there was no way to adequately regulate DDT use. Ruckelshaus' conclusion was that DDT could not be used safely. History professor Gary Kroll wrote, "Rachel Carson's Silent Spring played a large role in articulating ecology as a 'subversive subject'—as a perspective that cuts against the grain of materialism, scientism, and the technologically engineered control of nature."

In a 2013 interview, Ruckelshaus briefly recounted his decision to ban DDT except for emergency uses, noting that Carson's book featured DDT and for that reason the issue drew considerable public attention.

Former Vice President of the United States and environmentalist Al Gore wrote an introduction to the 1992 edition of Silent Spring. He wrote: "Silent Spring had a profound impact ... Indeed, Rachel Carson was one of the reasons that I became so conscious of the environment and so involved with environmental issues  ...  [she] has had as much or more effect on me than any, and perhaps than all of them together."

Debate over environmentalism and DDT restrictions

Carson has been targeted by some organizations opposed to the environmental movement, including Roger Bate of the pro-DDT advocacy group Africa Fighting Malaria and the libertarian think tank Competitive Enterprise Institute; these sources oppose restrictions on DDT, attribute large numbers of deaths to such restrictions, and argue that Carson was responsible for them. These arguments have been dismissed as "outrageous" by former WHO scientist Socrates Litsios. May Berenbaum, University of Illinois entomologist, says, "to blame environmentalists who oppose DDT for more deaths than Hitler is worse than irresponsible." Investigative journalist Adam Sarvana and others characterize this notion as a "myth" promoted principally by Roger Bate of the pro-DDT advocacy group Africa Fighting Malaria (AFM).

In the 1990s and 2000s, campaigns against the book intensified, in part due to efforts by the tobacco industry to cast larger doubt on science-driven policy as a way of contesting bans on smoking. In 2009, the heavily corporate-funded libertarian think tank Competitive Enterprise Institute set up a website falsely blaming Carson for deaths to malaria. This triggered a point-by-point rebuttal by biographer William Souder, who reviewed the distortions used by campaigners against Silent Spring.

A 2012 review article in Nature by Rob Dunn commemorating the 50th anniversary of Silent Spring and summarizing the progressive environmental-policy changes made since then, prompted a response in a letter written by Anthony Trewavas and co-signed by 10 others, including Christopher Leaver, Bruce Ames, Richard Tren and Peter Lachmann, who quote estimates of 60 to 80 million deaths "as a result of misguided fears based on poorly understood evidence".

Biographer Hamilton Lytle believes these estimates are unrealistic, even if Carson can be "blamed" for worldwide DDT policies. John Quiggin and Tim Lambert wrote, "the most striking feature of the claim against Carson is the ease with which it can be refuted". DDT was never banned for anti-malarial use, and its ban for agricultural use in the United States in 1972 did not apply outside the U.S. nor to anti-malaria spraying. The international treaty that banned most uses of DDT and other organochlorine pesticides—the 2001 Stockholm Convention on Persistent Organic Pollutants (which became effective in 2004)—included an exemption for the use of DDT for malaria control until affordable substitutes could be found. Mass outdoor spraying of DDT was abandoned in poor countries subject to malaria, such as Sri Lanka, in the 1970s and 1980s; this was not because of government prohibitions but because the DDT had lost its ability to kill the mosquitoes. Because of insects' very short breeding cycle and large number of offspring, the most resistant insects survive and pass on their genetic traits to their offspring, which replace the pesticide-slain insects relatively rapidly. Agricultural spraying of pesticides produces pesticide resistance in seven to ten years.

Some experts have said that restrictions placed on the agricultural use of DDT have increased its effectiveness for malaria control. According to pro-DDT advocate Amir Attaran, the result of the (activated in 2004) Stockholm Convention banning DDT's use in agriculture "is arguably better than the status quo ... For the first time, there is now an insecticide which is restricted to vector control only, meaning that the selection of resistant mosquitoes will be slower than before."

Legacy

Silent Spring has been featured in many lists of the best nonfiction books of the twentieth century. It was fifth in the Modern Library List of Best 20th-Century Nonfiction and number 78 in the National Review's 100 best non-fiction books of the 20th century. In 2006, Silent Spring was named one of the 25 greatest science books of all time by the editors of Discover Magazine. In 2012, the American Chemical Society designated the legacy of Silent Spring a National Historic Chemical Landmark at Chatham University in Pittsburgh.

In 1996, a follow-up book, Beyond Silent Spring, co-written by H.F. van Emden and David Peakall, was published.

In 2011, the American composer Steven Stucky wrote the eponymously titled symphonic poem Silent Spring to commemorate the fiftieth anniversary of the book's publication. The piece was given its world premiere in Pittsburgh on February 17, 2012, with the conductor Manfred Honeck leading the Pittsburgh Symphony Orchestra.

Naturalist David Attenborough has stated that Silent Spring was probably the book that had changed the scientific world the most, after the Origin of Species by Charles Darwin.

Sense about Science

From Wikipedia, the free encyclopedia
 
Sense about Science
Sense about Science logo.jpg
Founded2002
FounderLord Taverne
TypeCharitable trust No.1146170
Location
Area served
Europe
Key people
Revenue (2018)
£520,134
Employees (2018)
11
Volunteers (2018)
40
Websitesenseaboutscience.org

Sense about Science is a United Kingdom charitable organization that promotes the public understanding of science. Sense about Science was founded in 2002 by Lord Taverne, Bridget Ogilvie and others to promote respect for scientific evidence and good science. Sense about Science was established as a charitable trust in 2003, with 14 trustees, an advisory council and a small office staff. Tracey Brown has been the director since 2002.

Sense about Science works with scientists and journalists to put scientific evidence in public discussions about science, and to correct unscientific misinformation. They encourage and assist scientists to engage in public debates about their area of expertise, to respond to scientifically inaccurate claims in the media, to help people contact scientists with appropriate expertise, and to prepare briefings about the scientific background to issues of public concern.

Projects

Sense about Science publishes guides to different areas of science in partnership with experts. These include: Making Sense of Uncertainty, Making Sense of Allergies, Making Sense of Drug Safety Science, Making Sense of Crime, Making Sense of Statistics, Making Sense of Screening and Making Sense of GM.

Sense about Science runs the Voice of Young Science programme to help early career scientists engage in public debates. Sense About Science hosts an annual lecture.

Since its founding, Sense about Science has contributed to UK public debates about such subjects as alternative medicine, "detoxification" products and detox diets, genetically modified food, avian influenza, chemicals and health, "electrosmog", vaccination, weather and climate, nuclear power, and the use and utility of peer review. Sense about Science encourages scientists to explain to the public the value of peer review in determining which reports should be taken seriously. Director Tracey Brown describes such critical thinking as crucial to preventing public health scares based on unpublished information.

Causes

Sense About Science launched the Ask for Evidence campaign in 2011 to help people request for themselves the evidence behind news stories, marketing claims and policies.

AllTrials

The AllTrials campaign calls for all past and present clinical trials to be registered and their full methods and summary results reported.

AllTrials is an international initiative of Bad Science, BMJ, Centre for Evidence-based Medicine, Cochrane Collaboration, James Lind Initiative, PLOS and Sense About Science and is being led in the US by Sense About Science USA, Dartmouth's Geisel School of Medicine and the Dartmouth Institute for Health Policy & Clinical Practice.

As of January 2018, the AllTrials petition has been signed by 91,989 people and 737 organisations.

Ask for Evidence

Ask for Evidence was launched by Sense About Science in 2011. It is a campaign that helps people request for themselves the evidence behind news stories, marketing claims and policies. When challenged in this way, organisations may withdraw their claims or send evidence to support them. The campaign is supported by more than 6000 volunteer scientists who are available to review the evidence provided and determine whether it supports the original claim or story. The campaign has received funding from The Wellcome Trust and is endorsed by figures such as Dara Ó Briain and Derren Brown.

Keep Libel Laws Out of Science

Sense About Science launched the Keep Libel Laws out of Science campaign in June 2009 in defence of a member of its board of trustees, author and journalist Simon Singh, who has been sued for libel by the British Chiropractic Association. They issued a statement entitled "The law has no place in scientific disputes", which was signed by many people representing science, medicine, journalism, publishing, arts, humanities, entertainment, sceptics, campaign groups and law. In April 2010, the BCA lost this case with the court accepting that criticism of the BCA concerning its promotion of bogus treatments was fair comment.

In December 2009, Sense About Science, Index on Censorship and English PEN launched the Libel Reform Campaign. The Defamation Act 2013 received Royal Assent on 25 April 2013 and came into force on 1 January 2014.

The Trust actively campaigns in support of various causes. It has issued a statement signed by over 35 scientists asking the WHO to condemn homeopathy for diseases such as HIV.

Reception

Sense about Science and their publications have been cited a number of times in the popular press, most notably for encouraging celebrities and the public to think critically about scientific claims,criticizing marketing unsupported by research, decrying the unsubstantiated claims of homeopathy, supporting genetically modified crops, criticising 'do-it-yourself' health testing, denouncing detox products, warning against 'miracle cures', and promoting public understanding of peer review. They have received positive coverage in publications from the Royal Society and the U.S. National Science Foundation, and in the writings of scientists such as Ben Goldacre and Steven Novella.

Lord Taverne, chairman of Sense About Science, has criticised campaigns to ban plastic bags as counter-productive and being based on "bad science".

Anti-genetic-modification campaigners and academics have criticised Sense About Science for what they view as a failure to disclose industry connections of some advisers, and Private Eye reported that it had seen a draft of the Making Sense of GM guide that included Monsanto Company's former director of scientific affairs as an author. Tracey Brown, managing director of Sense About Science, rebutted these claims on the Science about Science website.

Homeopath Peter Fisher criticised Sense About Science, who have been working closely with NHS primary care trusts on the issue of funding for homeopathy, for being funded by the pharmaceutical industry; Sense About Science responded in a statement to Channel 4 News that "Peter Fisher's desperate comments show about as much grasp of reality as the homeopathic medicine he sells."

A 2016 piece in The Intercept was critical of Sense About Science's data on and support for flame retardant chemicals.

Chemophobia

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Chemophobia

Chemophobia (or chemphobia or chemonoia) is an aversion to or prejudice against chemicals or chemistry. The phenomenon has been ascribed both to a reasonable concern over the potential adverse effects of synthetic chemicals, and to an irrational fear of these substances because of misconceptions about their potential for harm, particularly the possibility of certain exposures to some synthetic chemicals elevating an individual's risk of cancer. Consumer products with labels such as "natural" and "chemical-free" (the latter being impossible if taken literally, since all matter is made up of chemicals) appeal to chemophobic sentiments by offering consumers what appears to be a safer alternative (see appeal to nature).

Definition and uses

There are differing opinions on the proper usage of the word chemophobia. The International Union of Pure and Applied Chemistry (IUPAC) defines chemophobia as an "irrational fear of chemicals". According to the American Council on Science and Health, chemophobia is a fear of synthetic substances arising from "scare stories" and exaggerated claims about their dangers prevalent in the media.

Despite containing the suffix -phobia, the majority of written work focusing on addressing chemophobia describes it as a non-clinical aversion or prejudice, and not as a phobia in the standard medical definition. Chemophobia is generally addressed by chemical education and public outreach despite the fact that much chemophobia is economic or political in nature.

Michelle Francl has written: "We are a chemophobic culture. Chemical has become a synonym for something artificial, adulterated, hazardous, or toxic." She characterizes chemophobia as "more like color blindness than a true phobia" because chemophobics are "blind" to most of the chemicals that they encounter: every substance in the universe is a chemical. Francl proposes that such misconceptions are not innocuous, as demonstrated in one case by local statutes opposing the fluoridation of public water despite documented cases of tooth loss and nutritional deficit. In terms of risk perception, naturally occurring chemicals feel safer than synthetic ones to most people. Consequently, people fear man-made or "unnatural" chemicals, while accepting natural chemicals that are known to be dangerous or poisonous.

The Carcinogenic Potency Project, which is a part of the US EPA's Distributed Structure-Searchable Toxicity (DSSTox) Database Network, has been systemically testing the carcinogenicity of chemicals, both natural and synthetic, and building a publicly available database of the results since the 1980s. Their work attempts to fill in the gaps in our scientific knowledge of the carcinogenicity of all chemicals, both natural and synthetic, as the scientists conducting the Project described in the journal, Science, in 1992:

Toxicological examination of synthetic chemicals, without similar examination of chemicals that occur naturally, has resulted in an imbalance in both the data on and the perception of chemical carcinogens. Three points that we have discussed indicate that comparisons should be made with natural as well as synthetic chemicals.

1) The vast proportion of chemicals that humans are exposed to occur naturally. Nevertheless, the public tends to view chemicals as only synthetic and to think of synthetic chemicals as toxic despite the fact that every natural chemical is also toxic at some dose. The daily average exposure of Americans to burnt material in the diet is ~2000 mg, and exposure to natural pesticides (the chemicals that plants produce to defend themselves) is ~1500 mg. In comparison, the total daily exposure to all synthetic pesticide residues combined is ~0.09 mg. Thus, we estimate that 99.99% of the pesticides humans ingest are natural. Despite this enormously greater exposure to natural chemicals, 79% (378 out of 479) of the chemicals tested for carcinogenicity in both rats and mice are synthetic (that is, do not occur naturally).

2) It has often been wrongly assumed that humans have evolved defenses against the natural chemicals in our diet but not against the synthetic chemicals. However, defenses that animals have evolved are mostly general rather than specific for particular chemicals; moreover, defenses are generally inducible and therefore protect well from low doses of both synthetic and natural chemicals.

3) Because the toxicology of natural and synthetic chemicals is similar, one expects (and finds) a similar positivity rate for carcinogenicity among synthetic and natural chemicals. The positivity rate among chemicals tested in rats and mice is ~50%. Therefore, because humans are exposed to so many more natural than synthetic chemicals (by weight and by number), humans are exposed to an enormous background of rodent carcinogens, as defined by high-dose tests on rodents. We have shown that even though only a tiny proportion of natural pesticides in plant foods have been tested, the 29 that are rodent carcinogens among the 57 tested, occur in more than 50 common plant foods. It is probable that almost every fruit and vegetable in the supermarket contains natural pesticides that are rodent carcinogens.

In 2020 European Union Chemicals — Strategy for Sustainability has been described as a textbook example of pseudo-scientific and chemophobic regulation by David Zaruk, as it contains numerous references to "toxic-free environment", refers to equally controversial precautionary principle and refers to a pseudo-scientific article on Environmental Health News as reference for alleged link between endocrine disruptors and COVID-19 pandemics.

Causes and effects

Chemistry professor Pierre Laszlo [fr] writes that historically chemists have experienced chemophobia from the population at large, and considers that it is rooted both in irrational notions and in genuine concerns (such as those over chemical warfare and industrial disasters). Professor Gordon Gribble has written that the start of chemophobia could arguably be attributed to Silent Spring, and that subsequent events such as the contamination of Times Beach and the disaster at Bhopal, India only exacerbated the situation.

These events have led to association between the word "chemical" and notions of things that unnatural or artificial and also dangerous, and the opposite has occurred, where goods are marketed as "chemical free" or "natural", to avoid this association, which in turn reinforces the misconception that "chemicals" are unnatural and dangerous. The chemical industry has moved to make chemicals used as flavoring or aromas using biotechnology instead of synthetic chemistry, as the products can be marketed as "natural".

According to the industry advocacy group American Council on Science and Health, chemophobia is a growing phenomenon among the American public and has reached "epidemic" proportions among the general public. In a book published by the Council, Jon Entine writes that this is in part due to the propensity of people to show alarm at the reported presence of chemicals in their body, or in the environment, even when the chemicals are present in "minuscule amounts" which are in fact safe. Elsewhere, Entine has argued that chemophobia is linked to a precautionary principle in agricultural policy, which could jeopardize the world's ability to feed its ever-expanding population.

In the United Kingdom, Sense About Science produced a leaflet aimed at educating celebrities about science, in which it said that humans carry only small amounts of "chemical baggage" and that it is only because of advances in analytical chemistry that we can detect these traces at all.

Philip Abelson has argued that the practice of administering huge doses of substances to animals in laboratory experiments, when testing for carcinogenic potential, has led to public chemophobia by raising unjustified fears over those substances' effect on humans. He sees an opportunity cost in the "phantom hazards" such testing conjures, as it distracts from attention on known hazards posed to human health.

What Is Life?

From Wikipedia, the free encyclopedia

What Is Life? The Physical
Aspect of the Living Cell
Was ist Leben (1)-OG.JPG
Title pages of 1948 edition
AuthorErwin Schrödinger
CountryUnited Kingdom (UK)
LanguageEnglish
GenrePopular science
PublisherCambridge University Press
Publication date
1944
Media typePrint
Pages194 pp.
ISBN0-521-42708-8
OCLC24503223
574/.01 20
LC ClassQH331 .S357 1982

What Is Life? The Physical Aspect of the Living Cell is a 1944 science book written for the lay reader by physicist Erwin Schrödinger. The book was based on a course of public lectures delivered by Schrödinger in February 1943, under the auspices of the Dublin Institute for Advanced Studies where he was Director of Theoretical Physics, at Trinity College, Dublin. The lectures attracted an audience of about 400, who were warned "that the subject-matter was a difficult one and that the lectures could not be termed popular, even though the physicist’s most dreaded weapon, mathematical deduction, would hardly be utilized." Schrödinger's lecture focused on one important question: "how can the events in space and time which take place within the spatial boundary of a living organism be accounted for by physics and chemistry?"

In the book, Schrödinger introduced the idea of an "aperiodic crystal" that contained genetic information in its configuration of covalent chemical bonds. In the 1950s, this idea stimulated enthusiasm for discovering the genetic molecule. Although the existence of some form of hereditary information had been hypothesized since 1869, its role in reproduction and its helical shape were still unknown at the time of Schrödinger's lecture. In retrospect, Schrödinger's aperiodic crystal can be viewed as a well-reasoned theoretical prediction of what biologists should have been looking for during their search for genetic material.[citation needed] Both James D. Watson, and Francis Crick, who jointly proposed the double helix structure of DNA based on, amongst other theoretical insights, X-ray diffraction experiments by Rosalind Franklin, credited Schrödinger's book with presenting an early theoretical description of how the storage of genetic information would work, and each independently acknowledged the book as a source of inspiration for their initial researches.

Background

The book is based on lectures delivered under the auspices of the Dublin Institute for Advanced Studies, at Trinity College, Dublin, in February 1943 and published in 1944. At that time, although DNA was known to be a constituent of cell nuclei, the concept of a "heredity molecule" was strictly theoretical, with various candidates. One of the most successful branches of physics at this time was statistical physics, and quantum mechanics, a theory which is also very statistical in its nature. Schrödinger himself is one of the founding fathers of quantum mechanics.

Max Delbrück's thinking about the physical basis of life was an important influence on Schrödinger. However, long before the publication of What is Life?, geneticist and 1946 Nobel-prize winner H. J. Muller had in his 1922 article "Variation due to Change in the Individual Gene" already laid out all the basic properties of the "heredity molecule" (then not yet known to be DNA) that Schrödinger was to re-derive in 1944 "from first principles" in What is Life? (including the "aperiodicity" of the molecule), properties which Muller specified and refined additionally in his 1929 article "The Gene As The Basis of Life" and during the 1930s. Moreover, H. J. Muller himself wrote in a 1960 letter to a journalist regarding What Is Life? that whatever the book got right about the "hereditary molecule" had already been published before 1944 and that Schrödinger's were only the wrong speculations; Muller also named two famous geneticists (including Delbrück) who knew every relevant pre-1944 publication and had been in contact with Schrödinger before 1944. But DNA as the molecule of heredity became foremost only after Oswald Avery's bacterial-transformation experiments published in 1944; before those experiments, proteins were considered the most likely candidates. DNA was confirmed as the molecule in question by the Hershey–Chase experiment conducted in 1952.

Content

In chapter I, Schrödinger explains that most physical laws on a large scale are due to chaos on a small scale. He calls this principle "order-from-disorder." As an example he mentions diffusion, which can be modeled as a highly ordered process, but which is caused by random movement of atoms or molecules. If the number of atoms is reduced, the behaviour of a system becomes more and more random. He states that life greatly depends on order and that a naïve physicist may assume that the master code of a living organism has to consist of a large number of atoms.

In chapter II and III, he summarizes what was known at this time about the hereditary mechanism. Most importantly, he elaborates the important role mutations play in evolution. He concludes that the carrier of hereditary information has to be both small in size and permanent in time, contradicting the naïve physicist's expectation. This contradiction cannot be resolved by classical physics.

In chapter IV, Schrödinger presents molecules, which are indeed stable even if they consist of only a few atoms, as the solution. Even though molecules were known before, their stability could not be explained by classical physics, but is due to the discrete nature of quantum mechanics. Furthermore, mutations are directly linked to quantum leaps.

He continues to explain, in chapter V, that true solids, which are also permanent, are crystals. The stability of molecules and crystals is due to the same principles and a molecule might be called "the germ of a solid." On the other hand, an amorphous solid, without crystalline structure, should be regarded as a liquid with a very high viscosity. Schrödinger believes the heredity material to be a molecule, which unlike a crystal does not repeat itself. He calls this an aperiodic crystal. Its aperiodic nature allows it to encode an almost infinite number of possibilities with a small number of atoms. He finally compares this picture with the known facts and finds it in accordance with them.

In chapter VI Schrödinger states:

...living matter, while not eluding the "laws of physics" as established up to date, is likely to involve "other laws of physics" hitherto unknown, which however, once they have been revealed, will form just as integral a part of science as the former.

He knows that this statement is open to misconception and tries to clarify it. The main principle involved with "order-from-disorder" is the second law of thermodynamics, according to which entropy only increases in a closed system (such as the universe). Schrödinger explains that living matter evades the decay to thermodynamical equilibrium by homeostatically maintaining negative entropy in an open system.

In chapter VII, he maintains that "order-from-order" is not absolutely new to physics; in fact, it is even simpler and more plausible. But nature follows "order-from-disorder", with some exceptions as the movement of the celestial bodies and the behaviour of mechanical devices such as clocks. But even those are influenced by thermal and frictional forces. The degree to which a system functions mechanically or statistically depends on the temperature. If heated, a clock ceases to function, because it melts. Conversely, if the temperature approaches absolute zero, any system behaves more and more mechanically. Some systems approach this mechanical behaviour rather fast with room temperature already being practically equivalent to absolute zero.

Schrödinger concludes this chapter and the book with philosophical speculations on determinism, free will, and the mystery of human consciousness. He attempts to "see whether we cannot draw the correct non-contradictory conclusion from the following two premises: (1) My body functions as a pure mechanism according to Laws of Nature; and (2) Yet I know, by incontrovertible direct experience, that I am directing its motions, of which I foresee the effects, that may be fateful and all-important, in which case I feel and take full responsibility for them. The only possible inference from these two facts is, I think, that I – I in the widest meaning of the word, that is to say, every conscious mind that has ever said or felt 'I' – am the person, if any, who controls the 'motion of the atoms' according to the Laws of Nature". Schrödinger then states that this insight is not new and that Upanishads considered this insight of "ATHMAN = BRAHMAN" to "represent quintessence of deepest insights into the happenings of the world." Schrödinger rejects the idea that the source of consciousness should perish with the body because he finds the idea "distasteful". He also rejects the idea that there are multiple immortal souls that can exist without the body because he believes that consciousness is nevertheless highly dependent on the body. Schrödinger writes that, to reconcile the two premises,

The only possible alternative is simply to keep to the immediate experience that consciousness is a singular of which the plural is unknown; that there is only one thing and that what seems to be a plurality is merely a series of different aspects of this one thing…

Any intuitions that consciousness is plural, he says, are illusions. Schrödinger is sympathetic to the Hindu concept of Brahman, by which each individual's consciousness is only a manifestation of a unitary consciousness pervading the universe — which corresponds to the Hindu concept of God. Schrödinger concludes that "...'I' am the person, if any, who controls the 'motion of the atoms' according to the Laws of Nature." However, he also qualifies the conclusion as "necessarily subjective" in its "philosophical implications". In the final paragraph, he points out that what is meant by "I" is not the collection of experienced events but "namely the canvas upon which they are collected." If a hypnotist succeeds in blotting out all earlier reminiscences, he writes, there would be no loss of personal existence — "Nor will there ever be."

Schrödinger's "paradox"

In a world governed by the second law of thermodynamics, all isolated systems are expected to approach a state of maximum disorder. Since life approaches and maintains a highly ordered state, some argue that this seems to violate the aforementioned second law, implying that there is a paradox. However, since the biosphere is not an isolated system, there is no paradox. The increase of order inside an organism is more than paid for by an increase in disorder outside this organism by the loss of heat into the environment. By this mechanism, the second law is obeyed, and life maintains a highly ordered state, which it sustains by causing a net increase in disorder in the Universe. In order to increase the complexity on Earth—as life does—free energy is needed and in this case is provided by the Sun.

Africanized bee

From Wikipedia, the free encyclopedia

Africanized bee
Apis mellifera scutellata.jpg
Scientific classification
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Hybrid (see text)

The Africanized bee, also known as the Africanized honey bee and known colloquially as the "killer bee", is a hybrid of the western honey bee (Apis mellifera), produced originally by crossbreeding of the East African lowland honey bee (A. m. scutellata) with various European honey bee subspecies such as the Italian honey bee (A. m. ligustica) and the Iberian honey bee (A. m. iberiensis).

The East African lowland honey bee was first introduced to Brazil in 1956 in an effort to increase honey production, but 26 swarms escaped quarantine in 1957. Since then, the hybrid has spread throughout South America and arrived in North America in 1985. Hives were found in south Texas in the United States in 1990.

Africanized honey bees are typically much more defensive than other varieties of honey bees, and react to disturbances faster than European honey bees. They can chase a person a quarter of a mile (400 m); they have killed some 1,000 humans, with victims receiving 10 times more stings than from European honey bees. They have also killed horses and other animals.

History

There are 29 recognized subspecies of Apis mellifera based largely on geographic variations. All subspecies are cross-fertile. Geographic isolation led to numerous local adaptations. These adaptations include brood cycles synchronized with the bloom period of local flora, forming a winter cluster in colder climates, migratory swarming in Africa, enhanced (long-distance) foraging behavior in desert areas, and numerous other inherited traits.

The Africanized honey bees in the Western Hemisphere are descended from hives operated by biologist Warwick E. Kerr, who had interbred honey bees from Europe and southern Africa. Kerr was attempting to breed a strain of bees that would produce more honey in tropical conditions than the European strain of honey bee currently in use throughout North, Central and South America. The hives containing this particular African subspecies were housed at an apiary near Rio Claro, São Paulo, in the southeast of Brazil, and were noted to be especially defensive. These hives had been fitted with special excluder screens (called queen excluders) to prevent the larger queen bees and drones from getting out and mating with the local population of European bees. According to Kerr, in October 1957 a visiting beekeeper, noticing that the queen excluders were interfering with the worker bees' movement, removed them, resulting in the accidental release of 26 Tanganyikan swarms of A. m. scutellata. Following this accidental release, the Africanized honey bee swarms spread out and crossbred with local European honey bee colonies.

The descendants of these colonies have since spread throughout the Americas, moving through the Amazon Basin in the 1970s, crossing into Central America in 1982, and reaching Mexico in 1985. Because their movement through these regions was rapid and largely unassisted by humans, Africanized honey bees have earned the reputation of being a notorious invasive species. The prospect of killer bees arriving in the United States caused a media sensation in the late 1970s, inspired several horror movies, and sparked debate about the wisdom of humans altering entire ecosystems.

The first Africanized honey bees in the U.S. were discovered in 1985 at an oil field in the San Joaquin Valley of California. Bee experts theorized the colony had not traveled overland but instead "arrived hidden in a load of oil-drilling pipe shipped from South America." The first permanent colonies arrived in Texas from Mexico in 1990. In the Tucson region of Arizona, a study of trapped swarms in 1994 found that only 15 percent had been Africanized; this number had grown to 90 percent by 1997.

Characteristics

Though Africanized honey bees display certain behavioral traits that make them less than desirable for commercial beekeeping, excessive defensiveness and swarming foremost, they have now become the dominant type of honey bee for beekeeping in Central and South America due to their genetic dominance as well as ability to out-compete their European counterpart, with some beekeepers asserting that they are superior honey producers and pollinators.

Africanized honey bees, as opposed to other Western bee types:

  • Tend to swarm more frequently and go farther than other types of honey bees.
  • Are more likely to migrate as part of a seasonal response to lowered food supply.
  • Are more likely to "abscond"—the entire colony leaves the hive and relocates—in response to stress.
  • Have greater defensiveness when in a resting swarm, compared to other honey bee types.
  • Live more often in ground cavities than the European types.
  • Guard the hive aggressively, with a larger alarm zone around the hive.
  • Have a higher proportion of "guard" bees within the hive.
  • Deploy in greater numbers for defense and pursues perceived threats over much longer distances from the hive.
  • Cannot survive extended periods of forage deprivation, preventing introduction into areas with harsh winters or extremely dry late summers.
  • Live in dramatically higher population densities.

North American distribution

Map showing the spread of Africanized honey bees in the United States from 1990 to 2003

Africanized honey bees are considered an invasive species in the Americas. As of 2002, the Africanized honey bees had spread from Brazil south to northern Argentina and north to Central America, Trinidad (the West Indies), Mexico, Texas, Arizona, Nevada, New Mexico, Florida, and southern California. Their expansion stopped for a time at eastern Texas, possibly due to the large population of European honey bee hives in the area. However, discoveries of the Africanized honey bees in southern Louisiana show that they have gotten past this barrier, or have come as a swarm aboard a ship.

In June 2005, it was discovered that the bees had entered Texas and had spread into southwest Arkansas. On 11 September 2007, Commissioner Bob Odom of the Louisiana Department of Agriculture and Forestry said that Africanized honey bees had established themselves in the New Orleans area. In February 2009, Africanized honey bees were found in southern Utah. The bees had spread into eight counties in Utah, as far north as Grand and Emery Counties by May 2017.

In October 2010, a 73-year-old man was killed by a swarm of Africanized honey bees while clearing brush on his south Georgia property, as determined by Georgia's Department of Agriculture. In 2012, Tennessee state officials reported that a colony was found for the first time in a beekeeper's colony in Monroe County in the eastern part of the state. In June 2013, 62-year-old Larry Goodwin of Moody, Texas was killed by a swarm of Africanized honey bees.

In May 2014, Colorado State University confirmed that bees from a swarm which had aggressively attacked an orchardist near Palisade, in west-central Colorado, were from an Africanized honey bee hive. The hive was subsequently destroyed.

In tropical climates they effectively out-compete European honey bees and, at their peak rate of expansion, they spread north at almost two kilometers (about one mile) a day. There were discussions about slowing the spread by placing large numbers of docile European-strain hives in strategic locations, particularly at the Isthmus of Panama, but various national and international agricultural departments could not prevent the bees' expansion. Current knowledge of the genetics of these bees suggests that such a strategy, had it been tried, would not have been successful.

As the Africanized honey bee migrates further north, colonies continue to interbreed with European honey bees. In a study conducted in Arizona in 2004 it was observed that swarms of Africanized honey bees could take over weakened European honey bee hives by invading the hive, then killing the European queen and establishing their own queen. There are now relatively stable geographic zones in which either Africanized honey bees dominate, a mix of Africanized and European honey bees is present, or only non-Africanized honey bees are found, as in the southern portions of South America or northern North America.

An Africanized honey bee hive on Gila River Indian Community land

African honey bees abscond (abandon the hive and any food store to start over in a new location) more readily than European honeybees. This is not necessarily a severe loss in tropical climates where plants bloom all year, but in more temperate climates it can leave the colony with not enough stores to survive the winter. Thus Africanized honey bees are expected to be a hazard mostly in the southern states of the United States, reaching as far north as the Chesapeake Bay in the east. The cold-weather limits of the Africanized honey bee have driven some professional bee breeders from Southern California into the harsher wintering locales of the northern Sierra Nevada and southern Cascade Range. This is a more difficult area to prepare bees for early pollination placement in, such as is required for the production of almonds. The reduced available winter forage in northern California means that bees must be fed for early spring buildup.

The arrival of the Africanized honey bee in Central America is threatening the ancient art of keeping Melipona stingless bees in log gums, although they do not interbreed or directly compete with each other. The honey production from a single hive of Africanized honey bees can be 100 kg annually and far exceeds the much smaller 3–5 kg of the various Melipona stingless bee species. Thus economic pressures are forcing beekeepers to switch from the traditional stingless bees of their ancestors to the new reality of the Africanized honey bee. Whether this will lead to their extinction is unknown, but they are well adapted to exist in the wild, and there are a number of indigenous plants that the Africanized honey bees do not visit, so their fate remains to be seen.

Africanized honey bees gathering pollen at an Engelmann's prickly pear in the Mojave Desert

Foraging behavior

Africanized honey bees have a set of characteristics with respect to foraging behavior. Africanized honey bees begin foraging at young ages and harvest a greater quantity of pollen with respect to their European counterparts (Apis mellifera ligustica). This may be linked to the high reproductive rate of the Africanized honey bee which requires pollen to feed the greater number of larvae. Africanized honey bees are also sensitive to sucrose at lower concentrations. This adaptation causes foragers to harvest resources with low concentrations of sucrose that include water, pollen, and unconcentrated nectar. A study comparing A. m. scutellata and A. m. ligustica published by Fewell and Bertram in 2002 suggests that the differential evolution of this suite of behaviors is due to the different environmental pressures experienced by African and European subspecies.

Proboscis extension responses

Honey bee sensitivity to different concentrations of sucrose is determined by a reflex known as the proboscis extension response or PER. Different species of honey bees that employ different foraging behaviors will vary in the concentration of sucrose that elicits their proboscis extension response.

For example, European honey bees (Apis mellifera ligustica) forage at older ages and harvest less pollen and more concentrated nectar. The differences in resources emphasized during harvesting are a result of the European honey bee's sensitivity to sucrose at higher concentrations.

Evolution

The differences in a variety of behaviors between different species of honey bees are the result of a directional selection that acts upon several foraging behavior traits as a common entity. Selection in natural populations of honey bees show that positive selection of sensitivity to low concentrations of sucrose are linked to foraging at younger ages and collecting resources low in sucrose. Positive selection of sensitivity to high concentrations of sucrose were linked to foraging at older ages and collecting resources higher in sucrose. Additionally of interest, “change in one component of a suite of behaviors appear[s] to direct change in the entire suite.”

When resource density is low in Africanized honey bee habitats, it is necessary for the bees to harvest a greater variety of resources because they cannot afford to be selective. Honey bees that are genetically inclined towards resources high in sucrose like concentrated nectar will not be able to sustain themselves in harsher environments. The noted PER to low sucrose concentration in Africanized honey bees may be a result of selective pressure in times of scarcity when their survival depends on their attraction to low quality resources.

Morphology and genetics

The popular term "killer bee" has only limited scientific meaning today because there is no generally accepted fraction of genetic contribution used to establish a cut-off.

Morphological tests

Although the native East African lowland honey bees (Apis mellifera scutellata) are smaller and build smaller comb cells than the European honey bees, their hybrids are not smaller. Africanized honey bees have slightly shorter wings, which can only be recognized reliably by performing a statistical analysis on micro-measurements of a substantial sample.

An African honey bee extracts nectar from a flower as pollen grains stick to its body in Tanzania (this is a purebred African honey bee, not an 'Africanized' hybrid honey bee).

One of the problems with this test is that there are other subspecies, such as Apis mellifera iberiensis, which also have shortened wings. This trait is hypothesized to derive from ancient hybrid haplotypes thought to have links to evolutionary lineages from Africa. Some belong to Apis mellifera intermissa, but others have an indeterminate origin; the Egyptian honeybee (Apis mellifera lamarckii), present in small numbers in the southeastern U.S., has the same morphology.

DNA tests

Currently testing techniques have moved away from external measurements to DNA analysis, but this means the test can only be done by a sophisticated laboratory. Molecular diagnostics using the mitochondrial DNA (mtDNA) cytochrome b gene can differentiate A. m. scutellata from other A. mellifera lineages, though mtDNA only allows one to detect Africanized colonies that have Africanized queens and not colonies where a European queen has mated with Africanized drones. A test based on single nucleotide polymorphisms was created in 2015 to detect Africanized bees based on the proportion of African and European ancestry.

Western variants

The western honey bee is native to the continents of Europe, Asia, and Africa. As of the early 1600s, it was introduced to North America, with subsequent introductions of other European subspecies 200 years later. Since then, they have spread throughout the Americas. The 29 subspecies can be assigned to one of four major branches based on work by Ruttner and subsequently confirmed by analysis of mitochondrial DNA. African subspecies are assigned to branch A, northwestern European subspecies to branch M, southwestern European subspecies to branch C, and Mideast subspecies to branch O. The subspecies are grouped and listed. There are still regions with localized variations that may become identified subspecies in the near future, such as A. m. pomonella from the Tian Shan Mountains, which would be included in the Mideast subspecies branch.

The western honey bee is the third insect whose genome has been mapped, and is unusual in having very few transposons. According to the scientists who analyzed its genetic code, the western honey bee originated in Africa and spread to Eurasia in two ancient migrations. They have also discovered that the number of genes in the honey bee related to smell outnumber those for taste. The genome sequence revealed several groups of genes, particularly the genes related to circadian rhythms, were closer to vertebrates than other insects. Genes related to enzymes that control other genes were also vertebrate-like.

African variants

There are two lineages of the East African lowland subspecies (Apis mellifera scutellata) in the Americas: actual matrilineal descendants of the original escaped queens and a much smaller number that are Africanized through hybridization. The matrilineal descendants carry African mtDNA, but partially European nuclear DNA, while the honey bees that are Africanized through hybridization carry European mtDNA, and partially African nuclear DNA. The matrilineal descendants are in the vast majority. This is supported by DNA analyses performed on the bees as they spread northwards; those that were at the "vanguard" were over 90% African mtDNA, indicating an unbroken matriline, but after several years in residence in an area interbreeding with the local European strains, as in Brazil, the overall representation of African mtDNA drops to some degree. However, these latter hybrid lines (with European mtDNA) do not appear to propagate themselves well or persist. Population genetics analysis of Africanized honey bees in the United States, using a maternally inherited genetic marker, found 12 distinct mitotypes, and the amount of genetic variation observed supports the idea that there have been multiple introductions of AHB into the United States.

A newer publication shows the genetic admixture of the Africanized honey bees in Brazil. The small number of honey bees with African ancestry that were introduced to Brazil in 1956, which dispersed and hybridized with existing managed populations of European origin and quickly spread across much of the Americas, is an example of a massive biological invasion as earlier told in this article. Here, they analysed whole‐genome sequences of 32 Africanized honey bees sampled from throughout Brazil to study the effect of this process on genome diversity. By comparison with ancestral populations from Europe and Africa, they infer that these samples had 84% African ancestry, with the remainder from western European populations. However, this proportion varied across the genome and they identified signals of positive selection in regions with high European ancestry proportions. These observations are largely driven by one large gene‐rich 1.4 Mbp segment on chromosome 11 where European haplotypes are present at a significantly elevated frequency and likely confer an adaptive advantage in the Africanized honey bee population.

Consequences of selection

The chief difference between the European subspecies of honey bees kept by beekeepers and the African ones is attributable to both selective breeding and natural selection. By selecting only the most gentle, non-defensive subspecies, beekeepers have, over centuries, eliminated the more defensive ones and created a number of subspecies suitable for apiculture. The most common subspecies used in Europe and the United States today is the Italian honey bee (Apis mellifera ligustica), which has been used for over 1,000 years in some parts of the world and in the Americas since the arrival of the European colonists.

In Central and southern Africa there was formerly no tradition of beekeeping, and the hive was destroyed in order to harvest the honey, pollen and larvae. The bees adapted to the climate of Sub-Saharan Africa, including prolonged droughts. Having to defend themselves against aggressive insects such as ants and wasps, as well as voracious animals like the honey badger, African honey bees evolved as a subspecies group of highly defensive bees unsuitable by a number of metrics for domestic use.

As Africanized honey bees migrate into regions, hives with an old or absent queen can become hybridized by crossbreeding. The aggressive Africanized drones out-compete European drones for a newly developed queen of such a hive, ultimately resulting in hybridization of the existing colony. Requeening, a term for swapping out the old queen with a new, already fertilized one, can reduce hybridization in apiaries. As a prophylactic measure, the majority of beekeepers in North America tend to requeen their hives annually, maintaining strong colonies and avoiding hybridization.

Defensiveness

Africanized honey bees exhibit far greater defensiveness than European honey bees and are more likely to deal with a perceived threat by attacking in large swarms. These hybrids have been known to pursue a perceived threat for a distance of well over 500 meters (1,640 ft).

The venom of an Africanized honey bee is the same as that of a European honey bee, but since the former tends to sting in far greater numbers, deaths from them are naturally more numerous than from European honey bees. While allergies to the European honey bee may cause death, complications from Africanized honey bee stings are usually not caused from allergies to their venom. Humans stung many times by the Africanized honey bees can exhibit serious side effects such as inflammation of the skin, dizziness, headaches, weakness, edema, nausea, diarrhea, and vomiting. Some cases even progress to affecting different body systems by causing increased heart rates, respiratory distress, and even renal failure. Africanized honey bee sting cases can become very serious, but they remain relatively rare and are often limited to accidental discovery in highly populated areas.

Impact on humans

Fear factor

The Africanized honey bee is widely feared by the public, a reaction that has been amplified by sensationalist movies (such as The Swarm) and some of the media reports. Stings from Africanized honey bees kill on average one or two people per year.

As the Africanized honey bee spreads through Florida, a densely populated state, officials worry that public fear may force misguided efforts to combat them.

News reports of mass stinging attacks will promote concern and in some cases panic and anxiety, and cause citizens to demand responsible agencies and organizations to take action to help ensure their safety. We anticipate increased pressure from the public to ban beekeeping in urban and suburban areas. This action would be counter-productive. Beekeepers maintaining managed colonies of domestic European bees are our best defense against an area becoming saturated with AHB. These managed bees are filling an ecological niche that would soon be occupied by less desirable colonies if it were vacant.

— Florida African Bee Action Plan

Misconceptions

"Killer bee" is a term frequently used in media such as movies that portray aggressive behavior or actively seeking to attack humans. "Africanized honey bee" is considered a more descriptive term in part because their behavior is increased defensiveness compared to European honey bees that can exhibit similar defensive behaviors when disturbed.

The sting of the Africanized honey bee is no more potent than any other variety of honey bee, and although they are similar in appearance to European honey bees, they tend to be slightly smaller and darker in color. Although Africanized honey bees do not actively search for humans to attack, they are more dangerous because they are more easily provoked, quicker to attack in greater numbers, and then pursue the perceived threat farther, sometimes for up to a kilometer (approx. ​58 mile) or more.

While studies have shown that Africanized honey bees can infiltrate European honey bee colonies and then kill and replace their queen (thus usurping the hive), this is less common than other methods. Wild and managed colonies will sometimes be seen to fight over honey stores during the dearth (periods when plants are not flowering), but this behavior should not be confused with the aforementioned activity. The most common way that a European honey bee hive will become Africanized is through crossbreeding during a new queen's mating flight. Studies have consistently shown that Africanized drones are more numerous, stronger and faster than their European cousins and are therefore able to out-compete them during these mating flights. The results of mating between Africanized drones and European queens is almost always Africanized offspring.

Impact on apiculture

In areas of suitable temperate climate, the survival traits of Africanized honey bee colonies help them outperform European honey bee colonies. They also return later and basically work under conditions that often keep European honey bees hive-bound. This is the reason why they have gained a well-deserved reputation as superior honey producers, and those beekeepers who have learned to adapt their management techniques now seem to prefer them to their European counterparts. Studies show that in areas of Florida that contain Africanized honey bees, the honey production is higher than in areas in which they do not live. It is also becoming apparent that Africanized honey bees have another advantage over European honey bees in that they seem to show a higher resistance to several health issues, including parasites such as Varroa destructor, some fungal diseases like chalkbrood and even the mysterious colony collapse disorder which is currently plaguing beekeepers. So despite all its negative factors, it is possible that the Africanized honey bee might actually end up being a boon to apiculture.

Queen management

In areas where Africanized honey bees are well established, bought and pre-fertilized (i.e. mated) European queens can be used to maintain a hive's European genetics and behavior. However, this practice can be expensive, since these queens must be bought and shipped from breeder apiaries in areas completely free of Africanized honey bees, such as the northern U.S. states or Hawaii. As such, this is generally not practical for most commercial beekeepers outside the U.S., and it is one of the main reasons why Central and South American beekeepers have had to learn to manage and work with the existing Africanized honey bee. Any effort to crossbreed virgin European queens with Africanized drones will result in the offspring exhibiting Africanized traits; only 26 swarms escaped in 1957, and nearly 60 years there does not appear to be a noticeable lessening of the typical Africanized characteristics.

Gentleness

Not all Africanized honey bee hives display the typical hyper-defensive behavior, which may provide bee breeders a point to begin breeding a gentler stock (gAHBs). Work has been done in Brazil towards this end, but in order to maintain these traits, it is necessary to develop a queen breeding and mating facility in order to requeen colonies and to prevent reintroduction of unwanted genes or characteristics through unintended crossbreeding with feral colonies. In Puerto Rico, some bee colonies are already beginning to show more gentle behavior. This is believed to be because the more gentle bees contain genetic material that is more similar to the European honey bee, although they also contain Africanized honey bee material. This degree of aggressiveness is surprisingly almost unrelated to individual genetics - instead being almost entirely determined by the entire hive's proportion of aggression genetics. Also while bee incidents are much less common than they were during the first wave of Africanized honey bee colonization, this can be largely attributed to modified and improved bee management techniques. Prominent among these are locating bee-yards much further from human habitation, creating barriers to keep livestock at enough of a distance to prevent interaction, and education of the general public to teach them how to properly react when feral colonies are encountered and what resources to contact. The Africanized honey bee is considered the honey bee of choice for beekeeping in Brazil.

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