Barbara-McClintock

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Six Women Who Changed Science. And The World. Part 2.

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Ten Historic Female Scientists You Should Know

Emilie du Chatelet (1706 – 1749)

Gabrielle-Emilie Le Tonnelier de Breteuil, the daughter of the French court’s chief of protocol, married the marquis du Chatelet in 1725. She lived the life of a courtier and bore three children. But at age 27, she began studying mathematics seriously and then branched into physics. This interest intensified as she began an affair with the philosopher Voltaire, who also had a love of science. Their scientific collaborations—they outfitted a laboratory at du Chatelet’s home, Chateau de Cirey, and, in a bit of a competition, each entered an essay into a contest on the nature of fire (neither won)—outlasted their romance. Du Chatelet’s most lasting contribution to science was her French translation of Isaac Newton’s Principia, which is still in use today. At age 43, she fell in love with a young military officer and became pregnant; she died following complications during the birth of their child.

Caroline Herschel (1750 – 1848)

Herschel was little more than the household drudge for her parents in Hanover, Germany (she would later describe herself as the “Cinderella of the family”), when her older brother, William, brought her to England in 1772 to run his household in Bath. After she mastered the art of singing—to accompany William, who was the organist for the Octagon Chapel—her brother switched careers and went into astronomy. Caroline followed. In addition to assisting her brother in his observations and in the building of telescopes, Caroline became a brilliant astronomer in her own right, discovering new nebulae and star clusters. She was the first woman to discover a comet (she discovered eight in total) and the first to have her work published by the Royal Society. She was also the first British woman to get paid for her scientific work, when William, who had been named the king’s personal astronomer after his discovery of Uranus in 1781, persuaded his patron to reward his assistant with an annual salary. After William’s death in 1822, Caroline retired to Hanover. There she continued her astronomical work, compiling a catalogue of nebulae—the Herschels’ work had increased the number of known star clusters from 100 to 2,500. She died in 1848 at age 97 after receiving many honors in her field, including a gold medal from the Royal Astronomical Society.

Mary Anning (1799 – 1847)

In 1811, Mary Anning’s brother spotted what he thought was a crocodile skeleton in a seaside cliff near the family’s Lyme Regis, England, home. He charged his 11-year-old sister with its recovery, and she eventually dug out a skull and 60 vertebrae, selling them to a private collector for £23. This find was no croc, though, and was eventually named Ichthyosaurus, the “fish-lizard.” Thus began Anning’s long career as a fossil hunter. In addition to ichthyosaurs, she found long-necked plesiosaurs, a pterodactyl and hundreds, possibly thousands, of other fossils that helped scientists to draw a picture of the marine world 200 million to 140 million years ago during the Jurassic. She had little formal education and so taught herself anatomy, geology, paleontology and scientific illustration. Scientists of the time traveled from as far away as New York City to Lyme Regis to consult and hunt for fossils with Anning.

Mary Somerville (1780 – 1872)

Intrigued by the x’s and y’s in the answer to a math question in a ladies’ fashion magazine, 14-year-old Mary Fairfax of Scotland delved into the study of algebra and mathematics, defying her father’s injunction against such pursuits. Her studies were sidetracked by a marriage, in 1804, to a Russian Navy captain, but after his death she returned to Edinburgh and became involved in intellectual circles, associating with people such as the writer Sir Walter Scott and the scientist John Playfair, and resumed her studies in math and science. Her next husband, William Somerville, whom she wed in 1812, supported these efforts, and after they moved to London, Mary became host to her own intellectual circle, which included the astronomer John Herschel and the inventor Charles Babbage. She began experimenting on magnetism and produced a series of writings on astronomy, chemistry, physics and mathematics. She translated astronomer Pierre-Simon Laplace’s The Mechanism of the Heavens into English, and although she was unsatisfied with the result, it was used as a textbook for much of the next century. Somerville was one of the first two women, along with Caroline Herschel, to be named honorary members of the Royal Astronomical Society.

Maria Mitchell (1818 – 1889)

Young Maria Mitchell learned to observe the stars from her father, who used stellar observations to check the accuracy of chronometers for Nantucket, Massachusetts, whalers and taught his children to use a sextant and reflecting telescope. When Mitchell was 12, she helped her father record the time of an eclipse. And at 17, she had already begun her own school for girls, teaching them science and math. But Mitchell rocketed to the forefront of American astronomy in 1847 when she spotted a blurry streak—a comet—through her telescope. She was honored around the world, earning a medal from the king of Denmark, and became the first woman to be elected to the American Academy of Arts and Sciences. In 1857 Mitchell traveled to Europe, where she visited observatories and met with intellectuals, including Mary Somerville. Mitchell would write: “I could not help but admire [her] as a woman. The ascent of the steep and rugged path of science has not unfitted her for the drawing room circle; the hours of devotion to close study have not been incompatible with the duties of wife and mother.” Mitchell became the first female astronomy professor in the United States, when she was hired by Vassar College in 1865. There she continued her observations, particularly those of the Sun, traveling up to 2,000 miles to witness an eclipse.

Lise Meitner (1878 – 1968)

When Lise Meitner finished school at age 14, she was barred from higher education, as were all girls in Austria. But, inspired by the discoveries of William Röntgen and Henri Becquerel, she was determined to study radioactivity. When she turned 21, women were finally allowed into Austrian universities. Two years of tutoring preceded her enrollment at the University of Vienna; there she excelled in math and physics and earned her doctorate in 1906. She wrote to Marie Curie, but there was no room for her in the Paris lab and so Meitner made her way to Berlin. There she collaborated with Otto Hahn on the study of radioactive elements, but as an Austrian Jewish woman (all three qualities were strikes against her), she was excluded from the main labs and lectures and allowed to work only in the basement. In 1912, the pair moved to a new university and Meitner had better lab facilities. Though their partnership was split up physically when she was forced to flee Nazi Germany in 1938, they continued to collaborate. Meitner continued her work in Sweden and after Hahn discovered that uranium atoms were split when bombarded with neutrons, she calculated the energy released in the reaction and named the phenomenon “nuclear fission.” The discovery—which eventually led to the atomic bomb (“You must not blame scientists for the use to which war technicians have put our discoveries,” Meitner would say in 1945)—won Hahn the Nobel Prize in 1944. Meitner, overlooked by the Nobel committee, refused to return to Germany after the war and continued her atomic research in Stockholm into her 80s.

Irène Curie-Joliot (1897 – 1956)

The elder daughter of Pierre and Marie Curie, Irène followed her parents’ footsteps into the lab. The thesis for her 1925 doctor of science was on the alpha rays of polonium, one of the two elements her mother discovered. The next year, she married Frédéric Joliot, one of her mother’s assistants at the Radium Institute in Paris. Irène and Frédéric continued their collaboration inside the laboratory, pursuing research on the structure of the atom. In 1934, they discovered artificial radioactivity by bombarding aluminum, boron and magnesium with alpha particles to produce isotopes of nitrogen, phosphorus, silicon and aluminum. They received the Nobel Prize in chemistry the next year, making Marie and Irène the first parent-child couple to have independently won Nobels. All those years working with radioactivity took a toll, however, and Irène died of leukemia in 1956.

Barbara McClintock (1902 – 1992)

While studying botany at Cornell University in the 1920s, Barbara McClintock got her first taste of genetics and was hooked. As she earned her undergraduate and graduate degrees and moved into postdoctoral work, she pioneered the study of genetics of maize (corn) cells. She pursued her research at universities in California, Missouri and Germany before finding a permanent home at Cold Spring Harbor in New York. It was there that, after observing the patterns of coloration of maize kernels over generations of plants, she determined that genes could move within and between chromosomes. The finding didn’t fit in with conventional thinking on genetics, however, and was largely ignored; McClintock began studying the origins of maize in South America. But after improved molecular techniques that became available in the 1970s and early 1980s confirmed her theory and these “jumping genes” were found in microorganisms, insects and even humans, McClintock was awarded a Lasker Prize in 1981 and Nobel Prize in 1983.

Dorothy Hodgkin (1910 – 1994)

Dorothy Crowfoot (Hodgkin, after her 1937 marriage) was born in Cairo, Egypt, to a pair of British archaeologists. She was sent home to England for school, where she was one of only two girls who were allowed to study chemistry with the boys. At 18, she enrolled in one of Oxford’s women’s colleges and studied chemistry and then moved to Cambridge to study X-ray crystallography, a type of imaging that uses X-rays to determine a molecule’s three-dimensional structure. She returned to Oxford in 1934, where she would spend most of her working life, teaching chemistry and using X-ray crystallography to study interesting biological molecules. She spent years perfecting the technique, for which she was awarded a Nobel Prize in 1964, and determined the structures of penicillin, vitamin B12 and insulin. In 2010, 16 years after her death, the British Royal Mail celebrated the 350th anniversary of the Royal Society by issuing stamps with the likenesses of 10 of the society’s most illustrious members, including Isaac Newton and Benjamin Franklin; Hodgkin was the only woman in the group.

Rosalind Franklin (1920 – 1958)

James Watson and Francis Crick get credit for determining the structure of DNA, but their discovery relied on the work of Rosalind Franklin. As a teenager in the 1930s, Franklin attended one of the few girls’ schools in London that taught physics and chemistry, but when she told her father that she wanted to be a scientist, he rejected the idea. He eventually relented and she enrolled at Cambridge University, receiving a doctorate in physical chemistry. She learned techniques for X-ray crystallography while in Paris, returning to England in 1951 to work in the laboratory of John Randall at King’s College, London. There she made X-ray images of DNA. She had nearly figured out the molecule’s structure when Maurice Wilkins, another researcher in Randall’s lab who was also studying DNA, showed one of Franklin’s X-ray images to James Watson. Watson quickly figured out the structure was a double helix and, with Francis Crick, published the finding in the journal Nature. Watson, Crick and Wilkins won a Nobel Prize in 1962 for their discovery. Franklin, however, had died of ovarian cancer in 1958.

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Scientist Sundays: Barbara McClintock

Barbara McClintock is a distinguished cytogeneticist who led the research on maize cytogenetics. Her work studying how chromosomes change during replication was groundbreaking - such as her microscopic analysis of genetic recombination. She won the Nobel Laureate in 1983 for Physiology or Medicine for discovering transposition - mobile genetic elements.

Barbara McClintock by chid0 :

Barbara McClintock, who won the Nobel Prize in Physiology or Medicine in 1983 for her discovery of transposable genetic elements. The remarkable thing about her discovery is among other things the fact that she did so as early as the 1940’s. Way before anyone had an idea about molecular structure of DNA. Genetics was an obscure and unfashionable field at that time. Noone really believed her. Until all those famous others like Morgan, Watson, Crick, Pauling etc. made their discoveries - and her work was reestablished.

But there is another reason why I chose her, one that is even more important for me. Howard Green, a colleague, wrote this about her after she died in 1992:

"Barbara McClintock was a woman who rejected a woman’s life for herself. She began to do it as a small child and never deviated. Her childhood was not a happy one, and perhaps this provided the force, the moral tension that was so strong in her and so necessary for the life she lived. And we must not forget that at the foundation of every creative life there lies a sense of personal inadequacy that energizes the struggle. This sense was strong in Barbara."

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Barbara McClintock won the Nobel Prize in Physiology or Medicine in 1983 (she remains the only woman to have received an unshared prize in that category). She studied corn for most of her life, which might sound boring, but guess what? It was AWESOME CORN. Her corn studies allowed her to make significant discoveries and demonstrations in genetics, from the process of genetic recombination (crossing-over) to genetic mapping.

McClintock faced sexism in her field that prevented her from receiving proper recognition for her work for well, a long time (like, 30 or forty years).

LLS

thanks for the recommendation from troete

Barbara McClintock (1902-1992) was a botanist that specialized in the genetics of plants. (via Ten Historic Female Scientists You Should Know - smithsonianmag.com)

"While studying botany at Cornell University in the 1920s, Barbara McClintock got her first taste of genetics and was hooked. As she earned her undergraduate and graduate degrees and moved into postdoctoral work, she pioneered the study of genetics of maize (corn) cells. She pursued her research at universities in California, Missouri and Germany before finding a permanent home at Cold Spring Harbor in New York. It was there that, after observing the patterns of coloration of maize kernels over generations of plants, she determined that genes could move within and between chromosomes. The finding didn’t fit in with conventional thinking on genetics, however, and was largely ignored; McClintock began studying the origins of maize in South America. But after improved molecular techniques that became available in the 1970s and early 1980s confirmed her theory and these “jumping genes” were found in microorganisms, insects and even humans, McClintock was awarded a Lasker Prize in 1981 and Nobel Prize in 1983."


Read more: http://www.smithsonianmag.com/science-nature/Ten-Historic-Female-Scientists-You-Should-Know.html#ixzz2nlRN60s0
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Born on this day…  

Barbara McClintock (June 16, 1902 – September 2, 1992) was a United States geneticist. She won the Nobel Prize in physiology or medicine in 1983 for her discovery that certain genes in corn can move from one position to another along the length of a chromosome, causing genetic mutations. Many scientists had scoffed at her findings (first announced in 1951) because they ran contrary to the accepted theory that genes occurred at specific sites on chromosomes and were not able to move. Her research marked the beginning of modern molecular genetics.

McClintock was born in Hartford, Connecticut. She entered Cornell University’s Agriculture School in 1919, and earned a doctorate in plant genetics in 1927. McClintock held several faculty positions at Cornell and other universities in the 1920’s and 1930’s before joining the staff of the Carnegie Institute of Washington genetics laboratory at Cold Spring Harbor, on Long Island, in 1942.

To read more about genetics, visit HowStuffWorks.

Barbara McClintock began her scientific career at Cornell University, where she pioneered the study of cytogenetics-a new field in the 1930s-using maize as a model organism. Indeed, the marriage of cytology and genetics became official in 1931, when McClintock and graduate student Harriet Creighton provided the first experimental proof that genes were physically positioned on chromosomes by describing the crossing-over phenomenon and genetic recombination. Although Thomas Hunt Morgan was the first person to suggest the link between genetic traits and the exchange of genetic material by chromosomes, 20 years elapsed before his ideas were scientifically proven, largely due to limitations in cytological and experimental techniques (Coe & Kass, 2005). McClintock’s own innovative cytogenetic techniques allowed her to confirm Morgan’s ideas, and these techniques are numbered among her greatest contributions to science.

Discovering TEs Through Experimentation with Maize

As previously mentioned, McClintock is best known for her discovery of transposable elements through experimentation with maize. However, in order to understand McClintock’s observations and the logic that led to her discovery of TEs, it’s first necessary to be aware that the phenotypic system McClintock studied-the variegated color pattern of maize kernels-involves three alleles rather than the usual two.

More on Barbara McClintock:http://www.nature.com/scitable/topicpage/barbara-mcclintock-and-the-discovery-of-jumping-34083

source 

How do we know that pieces of DNA can jump around? Barbara McClintock

Barbara McClintock is a towering figure in the field of genetics and cell biology, with a career that spanned practically the entire 20th century. She’s perhaps best known for her discovery of transposable elements—bits of DNA that jump around the genome. But she was also the first to observe chromosomal crossing over and describe its relationship to genetic recombination. She described how chromosomes protect their ends and what happens when that protection goes away. And that’s just the highlights. The way the story is sometimes told, McClintock’s accomplishments were ignored until decades after the fact, but this isn’t strictly true. She was way too awesome to ignore, and had already been elected to the National Academy of Sciences (an incredibly prestigious appointment) by the time the work I’m going to describe would be published in 1950.

What people would fail to recognize was not her discovery of transposable elements, but the full significance and widespread applicability of her findings. Perhaps this is because she was truly ahead of her time. She would describe movable genes and genetic regulation before the structure of DNA was solved—even before DNA was universally accepted as the genetic material.

I don’t know if you’re getting this or not, but I really love Barbara McClintock.

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Barbara McClintock (1902 – 1992)

While studying botany at Cornell University in the 1920s, Barbara McClintock got her first taste of genetics and was hooked. As she earned her undergraduate and graduate degrees and moved into postdoctoral work, she pioneered the study of genetics of maize (corn) cells. She pursued her research at universities in California, Missouri and Germany before finding a permanent home at Cold Spring Harbor in New York. It was there that, after observing the patterns of coloration of maize kernels over generations of plants, she determined that genes could move within and between chromosomes. The finding didn’t fit in with conventional thinking on genetics, however, and was largely ignored; McClintock began studying the origins of maize in South America. But after improved molecular techniques that became available in the 1970s and early 1980s confirmed her theory and these “jumping genes” were found in microorganisms, insects and even humans, McClintock was awarded a Lasker Prize in 1981 and Nobel Prize in 1983.

Our Lady of Jumping Genes

Barbara McClintock (1902 – 1992)

Genetics

Barbara McClintock is best remembered for her discovery of transposons, mobile genetic elements that can ‘jump’ around the genome, but her work on maize genetics revolutionized many aspects of the field, including demonstrating genetic recombination, producing the first genetic map of maize, and demonstrating the role of the centromere and the telomere. Her work on mobile genetic elements was decades ahead of its time and not widely understood when she first introduced it, but she became the only woman to win an unshared Nobel Prize in Medicine or Physiology in 1983 because of her work. 

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