Information on history of genetics

Solo disponible en BuenasTareas
  • Páginas : 32 (7972 palabras )
  • Descarga(s) : 0
  • Publicado : 15 de septiembre de 2010
Leer documento completo
Vista previa del texto

Gregory Mendel (1822-1884), the discoverer of the gene and the founder of genetics was an Augustian monk from Brunn, Austria. In his spare time, Mendel bred pea plants in the monastery gardens. Many pea plants had many different traits, like some were were tall, some were short, some peas were smooth, others were wrinkly, etc. Mendel then tried to make hybrids. He did thisby snipping the male part of the plant to prevent "selfing" (pea plant can fertilize themselves). Then he dusted the female part with the desired "father." Then he tied bags over the flowers to prevent stray pollen from getting into the flowers. Thus, he was able to control the parentage of each generation. His first discovery was that tall plants crossed with short ones produced tall ones, notmedium ones. He then concluded that some genes were dominant and some were recessive. When he raised hybrids though, he found about 1/4 of them were short, but the other 3 were tall. He then concluded that genes are made of two distinct types, or alleles. A plant may have the same or different alleles (AA, aa, Aa). He found that hybrids can have small offspring, but if a plant with all dominantalleles are crossed with plants that have all dominant genes, all the offspring will have the dominant alleles (the same can be said for recessive too). It wasn't until 1900 when Mendel's works were actually noticed. Three men working independently, Hugo DeVries, Erich Von Tsohermark and Carl Correns did some experiments and came out with the same results as Mendel. They didn't take credit for it, butannounced that Mendel had had the same results and had done such testing first.

On Feb. 28, 1953, Francis Crick walked into the Eagle pub in Cambridge, England, and, as James Watson later recalled, announced that "we had found the secret of life." Actually, they had. That morning, Watson and Crick had figured out the structure of deoxyribonucleic acid, DNA. And that structure — a "doublehelix" that can "unzip" to make copies of itself — confirmed suspicions that DNA carries life's hereditary information.

Not until decades later, in the age of genetic engineering, would the Promethean power unleashed that day become vivid. But from the beginning, the Watson and Crick story had traces of hubris. As told in Watson's classic memoir, "The Double Helix," it was a tale of boundlessambition, impatience with authority and disdain, if not contempt, for received opinion. ("A goodly number of scientists," Watson explained, "are not only narrow-minded and dull but also just stupid.") Yet the Watson and Crick story is also one of sublime harmony, an example, as a colleague put it, of "that marvelous resonance between two minds — that high state in which 1 plus 1 does not equal 2 butmore like 10."

The men were in some ways an odd pair. The British Crick, at 35, still had no Ph.D. The American Watson, 12 years Crick's junior, had graduated from the University of Chicago at 19 and nabbed his doctorate at 22. But they shared a certain wanderlust, an indifference to boundaries. Crick had migrated from physics into chemistry and biology, fascinated by the line "between the livingand the nonliving." Watson had studied ornithology, then forsook birds for viruses, and then, doing postdoctoral work in Europe, took another sharp career turn.

At a conference in Naples, Watson saw a vague, ghostly image of a DNA molecule rendered by X-ray crystallography. DNA, he had heard, might be the stuff genes are made of. "A potential key to the secret of life was impossible to push outof my mind," he later wrote. "It was certainly better to imagine myself becoming famous than maturing into a stifled academic who had never risked a thought."

This theme of Watson's book — the hot pursuit of glory, the race against the chemist Linus Pauling for the Nobel Prize that DNA would surely bring--got bad reviews from the (relatively) genteel Crick. He didn't recall anyone mentioning...
tracking img