Tag Archives: Biology

Jew of the Week: Erwin Chargaff

Discovering DNA Structure

Erwin Chargaff (1905-2002) was born in what is now Chernivtsi, Ukraine (then part of the Austo-Hungarian Empire). His family was of the little-known Bukovinian Jewish community that blended elements of Ottoman, Romanian, Austrian, and Ukrainian culture and had a mix of Ashkenazi and Sephardi heritage and practice. During World War I, the family moved to Vienna, where Chargaff went on to study chemistry. In 1925, he took a job as professor of organic chemistry at Yale University. He moved to the University of Berlin in 1930 to head the chemistry lab for the bacteriology and public health department. During this time, he made some important findings about bacterial membranes and lipids. When the Nazis came to power, Chargaff was forced to resign and fled to Paris. After spending a couple of years doing research at the Pasteur Institute, Chargaff returned to the States to become a professor at Columbia University for the next four decades. This is where he did some of his most famous work, including on the mechanism of blood clotting. His main focus, however, was on the chemistry of mysterious DNA. He soon discovered that DNA always contained equal amounts of the nitrogen bases adenine and thymine, and equal amounts of cytosine and guanine, suggesting that the two sets pair up. (This would become known as the first of “Chargaff’s Rules”.) His 1950 paper was instrumental in allowing Watson and Crick to solve the puzzle of DNA structure just a few years later. In fact, it was a conversation that Chargaff had with Watson and Crick in 1952 which led them to deduce DNA’s double-helix structure. Not surprisingly, Chargaff protested when Watson and Crick won a Nobel Prize while he was excluded. Chargaff did win many other prizes, including the Pasteur Medal, the Heineken Prize, and the National Medal of Science. After retiring from Columbia, he continued to do research at the Roosevelt Hospital until the age of 87! Chargaff was highly critical of genetic engineering and biotechnology, saying that it would inevitably be abused and lead to a “molecular Auschwitz”. (Many today would say he was right!) Chargaff is often considered one of the fathers of biochemistry, and “Chargaff’s Rules” are still a fundamental concept taught in biology classes today.

Lag b’Omer Begins Saturday Night!

The Hidden History of Lag b’Omer

Reincarnation in Judaism (Video)

Words of the Week

There are two nuclei that man should never have touched: the atomic nucleus and the cell nucleus. The technology of genetic engineering poses a greater threat to the world than the advent of nuclear technology.
– Erwin Chargaff

Jews of the Week: The Minkowskis

Three Renowned Scientists

Hermann Minkowski

Hermann Minkowski (1864-1909) was born in what is now Lithuania, then part of Russia, and previously a part of Poland, to a wealthy Jewish family. His father was a merchant who paid for the construction of the famous Kovno Synagogue. In 1872, the Minkowskis fled the persecutions of the Russian Empire and settled in Germany. Hermann Minkowski went on to study mathematics and physics. In 1883 he won the Mathematics Prize of the French Academy of Sciences. He got his PhD two years later and taught at the Universities of Bonn, Konigsberg, Gottingen, and Zurich (where he was Albert Einstein’s teacher). Minkowski solved a number of big math problems, and actually improved upon Einstein’s theory of relativity, coming up with what is now called “Minkowski space-time”. He gave the mathematical proof for unifying space and time into a singular space-time continuum. Sadly, Minkowski met an untimely death at a young age from sudden appendicitis.

Oskar Minkowksi

His older brother was Oskar Minkowski (1858-1931), who studied biology and medicine. He went on to become a professor at the University of Breslau. (Since Jews were barred from holding such positions at the time, Minkowski had to nominally convert to Christianity.) In 1889, Minkowski did a number of operations on dogs and showed the link between the pancreas and diabetes. Together with Josef von Mering, Minkowski discovered how the pancreas controlled blood sugar levels, which later led to the discovery of insulin. Today, the Minkowski Prize is awarded each year for breakthroughs in diabetes research. His son was Rudolph Minkowski (1895-1976), who studied astronomy. He did important work dealing with supernovae, and later became the head of the famed Palomar Observatory, where he discovered a number of asteroids and nebulae. He also made important contributions in astrophysics, and won the Bruce Medal in 1961 for outstanding lifetime achievement in the field. The Minkowski Crater on the moon is named after him.

Can Jewish Homes Have Christmas Trees?

Words of the Week

In God there is no time or beginning to start, for He always existed and is
everlasting and in Him there is no beginning or end at all.
– Rabbi Chaim Vital, Etz Chaim

Jew of the Week: Lynn Margulis

The Rebel Evolutionist

Lynn Petra Alexander (1938-2011) was born in Chicago to a prominent Jewish (and passionately-Zionist) family. She got accepted to the University of Chicago when she was just 15 years old, and graduated with a BA four years later. That same year, she married (former Jew of the Week) Carl Sagan, then on his way to becoming a world-renowned scientist himself. She then went to the University of Wisconsin and earned her Master’s in genetics and zoology, followed by a PhD from UC Berkeley. Around that time, she divorced Carl Sagan and later married another scientist, Thomas Margulis. Although she divorced him as well, she kept the last name and is best known today as Lynn Margulis. In 1966, she became a biology professor at the University of Boston and remained there until 1988, when she became Distinguished Professor of Biology and Geosciences at the University of Massachusetts. Her 1967 paper “On the Origin of Mitosing Cells” was initially rejected by fifteen journals and stirred a great deal of controversy before being confirmed experimentally in 1978. Much of her research (and the opposition to it) was based on demonstrating major flaws within Darwin’s evolutionary theory. She would say that “Natural selection eliminates and maybe maintains, but it doesn’t create.” Margulis offered one hypothesis of her own, endosymbiosis, now a widely-accepted theory in biology and a key mechanism of evolution. Margulis also co-authored the first paper on the now-famous Gaia hypothesis regarding the intricate interactions between living things and the planet. Margulis worked tirelessly to the last days of her life. She co-authored another big (and controversial) paper in 2009—at the age of 71! Margulis has been called a “scientific rebel” and won countless awards, including a National Medal of Science from President Bill Clinton and a NASA Public Service Award for Astrobiology. She also has 15 honourary doctorates and was elected to the National Academy of Sciences. In 2002, she was ranked among the 50 most important women in science.

Words of the Week

We never judge a statement by its author, but only on its own merit.
– Rabbi Moshe Chaim Luzzatto (1707-1746), Derekh Tevunot