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| 2005/8/15-17 [Science/Biology] UID:39125 Activity:moderate |
8/15 One more player in the ID debate.
"Harvard to Investigate Origins of Life":
http://news.yahoo.com/s/ap/20050815/ap_on_sc/harvard_evolution
\_ It's probably a good idea. Someone needs to peel away the polemic
of ID and clearly highlight the evidence for or against evolution.
I think most people who distrust evolution do so because they don't
understand it. -emarkp
\_ The best evidence against evolution is the Second Coming of
Christ, unaided human levitation, reading of minds, or the
demonstration of anything else which a credible scientist would
classify as supernatural.
\_ Classification of something as 'supernatural' follows the
same pattern as classification of something as 'requiring
intelligence.' -- ilyas
\_ Someone levitate! Please! Use your own psychic energy!
\_ ilyas, tell us about the stars.
\_ Any sufficiently developed theory has evidence against it, but
the confirming evidence is greater. Just because there may be
points of evidence contradicting evolution doesn't mean I
advocate tossing it out or not teaching it in schools. And
the things you list don't necessarily contradict evolution.
I'm mostly interested in any postulated mechanism in which an
organism with X genes can evolve to have X+n genes. -emarkp
\_ Nah, I was just talking about the most direct path.
All it takes is just one levitating person, or one person
who can predict card sequences without cheating, and
that's the game!
To answer your last comment, bacterial resistance to
antibiotics via plasmids. PLEASE don't tell me: "I
meant mammals!"
\_ I didn't mean mammals--I'm not trying to trap anyone,
I'm genuinely interested in the research. A quick
google search doesn't help me understand how that's a
proof of what I'm looking for. Specifically, I'm not as
interested in speciation as I am in how an organism can
have more genes (not just different ones) than its
parents. Can you point me to a specific URL? -emarkp
\_ Does this help?
http://en.wikipedia.org/wiki/Antibiotic_resistant
http://en.wikipedia.org/wiki/Plasmid
If you really want to learn, buy Biology by
Campbell and Reece, 7th Ed.
\_ not how, but existence proof: every down's syndrome
child of non-down's syndrome parents. or have i mixed
that up?
\_ No, you've go it right. Every Down's syndrome
child's got an extra chromosome. Incidentally
also showing that most mutations are BAD.
\_ For a perfectly normal (and more extreme) version,
see 'the haploid/diploid life cycle.' -- ilyas
\_ http://en.wikipedia.org/wiki/Gene_duplication
\- this book is very good:
http://csua.org/u/d28 |
| news.yahoo.com/s/ap/20050815/ap_on_sc/harvard_evolution The team of researchers will receive $1 million in funding annually from Harvard over the next few years. The project begins with an admission th at some mysteries about life's origins cannot be explained. "My expectation is that we will be able to reduce this to a very simple s eries of logical events that could have taken place with no divine inter vention," said David R Liu, a professor of chemistry and chemical biolo gy at Harvard. The "Origins of Life in the Universe Initiative" is still in its early st ages, scientists told the Boston Sunday Globe. Harvard has told the rese arch team to make plans for adding faculty members and a collection of m ultimillion-dollar facilities. Evolution is a fundamental scientific theory that species evolved over mi llions of years. It has been standard in most public school science text s for decades but recently re-emerged in the spotlight as communities an d some states debated whether school children should also be taught abou t creationism or intelligent design. The theory of intelligent design says life on earth is too complex to hav e developed through evolution, implying that a higher power must have ha d a hand in creation. Harvard has not been seen as a leader in origins of life research, but th e university's vast resources could change that perception. "It is quite gratifying to see Harvard is going for a solution to a probl em that will be remembered 100 years from now," said Steven Benner, a Un iversity of Florida scientist who is one of the world's top chemists in origins-of-life research. The informati on contained in the AP News report may not be published, broadcast, rewr itten or redistributed without the prior written authority of The Associ ated Press. |
| en.wikipedia.org/wiki/Antibiotic_resistant those bact eria which have a mutation allowing them to survive will live on to repr oduce. They will then pass this trait to their offspring, which will be a fully resistant generation. Several studies have demonstrated that patterns of antibiotic usage great ly affect the number of resistant organisms which develop. c ephalosporins, greatly hastens the development of methicillin resistance , even in organisms that have never been exposed to the selective pressu re of methicillin per se. Other factors contributing towards resistance include incorrect diagnosis, unnecessary prescriptions, improper use of antibiotics by patients, and the use of antibiotics as livestock food ad ditives for growth promotion. methicillin-resistant Staphylococcus aureus) was first d etected in Britain in 1961 and is now "quite common" in hospitals. MRSA was responsible for 37% of fatal cases of blood poisoning in the UK in 1 999, up from 4% in 1991. Wash hands properly to reduce the chance of getting sick and spreadin g infection. Avoid raw eggs and u ndercooked meat, especially in ground form. When given antibiotics, take them exactly as prescrib ed and complete the full course of treatment; do not hoard pills for lat er use or share leftover antibiotics. This is because a v accine enhances the body's natural defenses, while an antibiotic operate s separately from the body's normal defenses. Nevertheless, new strains may evolve that escape immunity induced by vaccines. While theoretically promising, anti-staphylococcal vaccines have shown li mited efficacy, because of immunological variation between Staphylococcu s species, and the limited duration of effectiveness of the antibodies p roduced. Development and testing of more effective vaccines is under way . |
| en.wikipedia.org/wiki/Plasmid edit Types of plasmid One way of grouping plasmids is by their ability to transfer to other bac teria. Conjugative plasmids contain so-called tra-genes, which perform t he complex process of conjugation, the sexual transfer of plasmids to an other bacterium (Fig. Non-conjugative plasmids are incapable of init iating conjugation, hence they can only be transferred with the assistan ce of conjugative plasmids, by 'accident'. An intermediate class of plas mids are mobilisable, and carry only a subset of the genes required for transfer. These plasmids can 'parasitise' another plasmid, transferring at high frequency in the presence of a conjugative plasmid. It is possible for several different types of plasmids to coexist in a si ngle cell, eg, seven different plasmids have been found in E coli . On the other hand, related plasmids are often 'incompatible', resultin g in the loss of one of them from the cell line. Therefore, plasmids can be assigned into incompatibility groups, depending on their ability to coexist in a single cell. These incompatibility groupings are due to the regulation of vital plasmid functions. There are five mai n classes: * Fertility-plasmids, which contain tra-genes. cell division, in danger of being lost in one of the segregating bacteria. Such single-copy plasmids have systems which attempt to active ly distribute a copy to both daughter cells. There are many plasmids that are commercially availa ble for such uses. Initially, the gene to be replicated is inserted in a plasmid . These plasmids contain, in addition to the inserted gene, one or more genes capable of providing antibiotic resistance to the bacteri a that harbors them. transformation, which are then grown on specific antib iotic. Bacteria which took up one or more copies of the plasmid then express (make protein) the gene that confers antibiotic resistance. This is typically a protein which can break down any antibiotics that would otherwise kill the cell. As a result, only the bacteria with antibiotic resistance can survive, the very same bacteria containing the genes to b e replicated. The antibiotic will, however, kill those bacteria that did not receive a plasmid, because they have no antibiotic resistance ge nes. In this way the antibiotic acts as a filter selecting out only t he modified bacteria. Another major use of plasmids is to make large amounts of proteins. In th is case you grow the bacteria containing a plasmid harboring the gene of interest. Just as the bacteria produces proteins to confer its antibiot ic resistance, it can also be induced to produce large amounts of protei ns from the inserted gene. |
| en.wikipedia.org/wiki/Gene_duplication mutations will lead to loss of functionality and thus are selected against. When a gene is dup licated selection may be removed from one copy and now the other gene lo cus is free to mutate and discover new functions. It is predicted tha t the entire yeast genome underwent duplication only 1,000,000 years ag o Plants are the most prolific genome duplicators. polyploid organism) meaning it has six duplicate copies of its genome. The two genes that exists after a gene duplication event are paralogs. proteins with different function and/or stru cture as stated above. This is opposed to orthologous genes that code fo r proteins with similar function but that exists in different species. |
| csua.org/u/d28 -> www.amazon.com/exec/obidos/ASIN/0060932902/qid=1124253937/sr=2-1/ref=pd_bbs_b_2_1/002-2147905-4484807 com Science writer Matt Ridley has found a way to tell someone else's story w ithout being accused of plagiarism. Genome: The Autobiography of a Speci es in 23 Chapters delves deep within your body (and, to be fair, Ridley' s too) looking for dirt dug up by the Human Genome Project. Each chapter pries one gene out of its chromosome and focuses on its role in our dev elopment and adult life, but also goes further, exploring the implicatio ns of genetic research and our quickly changing social attitudes toward this information. Genome shies away from the "tedious biochemical middle managers" that only a nerd could love and instead goes for the A-materi al: genes associated with cancer, intelligence, sex (of course), and mor e Readers unfamiliar with the jargon of genetic research needn't fear; Ridl ey provides a quick, clear guide to the few words and concepts he must u se to translate hard science into English. His writing is informal, rela xed, and playful, guiding the reader so effortlessly through our 23 chro mosomes that by the end we wish we had more. He believes that the Human Genome Project will be as world-changing as the splitting of the atom; i f so, he is helping us prepare for exciting times--the hope of a cure fo r cancer contrasts starkly with the horrors of newly empowered eugenicis ts. Anyone interested in the future of the body should get a head start with the clever, engrossing Genome. From Publishers Weekly HSoon we'll know what's in our genes: next year, the Human Genome Project will have its first-draft map of our 23 chromosomes. The Origins of Virtue) anticipates the genomic news with an inventi vely constructed, riveting exposition of what we already know about the links between DNA and human life. His inviting prose proposes "to tell t he story of the human genome... chromosome by chromosome, by picking a g ene from each." That story begins with the basis of life on earth, the D NA-to-RNA-to-protein process (chapter one, "Life," and also chromosome o ne); the evolution of Homo sapiens (chromosome two, which emerged in ear ly hominids when two ape chromosomes fused); and the discovery of geneti c inheritance (which came about in part thanks to the odd ailment called alkaptonuria, carried on chromosome three). Some facts about your life depend entirely on a single gene--for example, whether you'll get the dr eadful degenerative disease Huntington's chorea, and if so, at what age (chromosome four, hence chapter four: "Fate"). But most facts about you are products of pleiotropy, "multiple effects of multiple genes," plus t he harder-to-study influences of culture and environment. sites in the genome" passes through "Intell igence," language acquisition, embryology, aging, sex and memory before arriving at two among many bugbears surrounding human genetic mapping: t he uses and abuses of genetic screening, and the ongoing debate on "gene tic determinism" and free will. Ridley can explain with equal verve diff icult moral issues, philosophical quandaries and technical biochemistry; he distinguishes facts from opinions well, and he's not shy about offer ing either. Among many recent books on genes, behavior and evolution, Ri dley's is one of the most informative. See all Editorial Reviews Product Details * Paperback: 352 pages * Publisher: Harper Perennial (October 3, 2000) * Language: English * ISBN: 0060932902 * Product Dimensions: 80 x 54 x 08 inches * Shipping Weight: 98 ounces. See all my revi ews I'm not sure whether to give this book four or five stars... FIVE STARS - because of how interesting the subject matter is. DNA, it se ems, isn't a brilliant piece of software to make bodies. FIVE STARS - because of how well written some sections are. Chapter 4, fo r instance, which talks about the researcher who not only can tell you I F you're going to get Huntington's chorea, but can tell you what age you 'll get it, simply by counting the number of times a particular gene seq uence repeats. I was left haunted by the question, if I had a high risk for HC, would I get the test done, simply to know when the symptoms wo uld start? This is the most up to date book on the subject available at the moment. BUT FOUR STARS - because although some parts were absolutely mind-blowing ly interesting and could be considered _classic_ bits of writing, the pr ose in other parts seemed to get a bit heavy and tedious, and I had to p ut it down. I was surprised by my own reaction, having been so thoroughl y entertained a few short chapters before. But it means I can't give it five stars, because that rating is for out and out classics. Ma tt Ridley unfolds the human genome for us in a crisply written and preci se "Autobiography of a Species in 23 Chapters." OK, I don't know what th e Hades that means, but this guy is a good writer, a smart scientist, an d a friendly teacher of what is a really cool, but intimidating, branch of learning. Ridley's got a little shtick, which he openly mocks himself, where his 23 chapters each represent one of the 23 human chromosomes. It's kind of a n interesting little angle, you want to like this guy, anyway, so the sh tick mostly works, although I don't really have a sense that each of our 23 chromosomes is a particular type of chromosome at the end of it. Genome is a lot of good science explained with a clear, well-constructed hand. In an excellent seven-page introduction, Ridley answered for me al l sorts of questions that my scientifically-literate yet communication-c hallenged science friends have been unable to answer, to wit: "Imagine that the genome is a book. Each chapter contains several thousand stories, called Genes. Each story is made up of paragraphs, called Exons, which are interrupted by advertisements called Introns. Very nicely done, brings it to an understandable level for the literate l ayperson, and establishes a very solid foundation from which he is able to unfold the rest of this story. He handles the basic science very well, and mostly shys away from the "Be lieve It or Not!" school of science reporting, though the occasional odd ity does pop up. One thing I found fascinating is the existence of "chim eras." Which is one creature ( a human, a mouse, anything) that has two different genomes in it: "Think of them as the opposite of identical twi ns: two different genomes in one body, instead of two different bodies w ith the same genome." This means that you could be the single body of tw o different people that had accidentally fused in the womb. He places humans and our development in the context of our nearest geneti c cousins - the chimpanzees and the gorillas and so forth. And elucidate s a number of compare and contrast thoughts: "What it means is that the mating system of the species was changing. The promiscuity of the chimp, with its short sexual liaisons, and the harem polygamy of the gorilla, were being replaced with something much more monogamous: a declining rat io of sexual dimorphism is unambiguous evidence for that." Enjoy all the learning, implications, and human foibles he packs into this one sentence on language acquisition: "Thus, although no other primate can learn grammatical language at all - and we are indebted to many diligent, sometimes gullible and certainly w ishful trainers of chimpanzees and gorillas for thoroughly exhausting al l possibilities to the contrary - language is intimately connected with sound production and processing." Even more enjoyable if you read it in an Eng lish accent on account of Ridley's living there according to the dust ja cket. In sum, if you are looking for an introduction to genetics, DNA, and our genome, and are the omnivore type of reader with a decent head on your s houlders, this book is for you. I enjoyed it tremendously and it's given me a very good grounding for my further reading into evolutionary psych ology. Of these, 22 pairs are numbered in or der of size from the largest (chromosome 1) to the smallest (chromosome 22), while the remaining pair consists of the sex chromosomes: 2 large X chromosomes in women, one X and one small Y in men. In size, the X come s between chromosomes 7 and 8, whereas the Y is the sma... |