Domnule Peter, Ce ati scris dvs mai jos e doar interpretarea simplista, sa nu-i spunem copilareasca, a unor articole privite singular.Daca ati fi in domeniul genetic ar fi trebuit sa fi citit pina acum despre teoria conform careia omul se afla in continua evolutie.Deci daca cimpanzeul si omul au avut in general multe in comun, conform evolutiei continue careia se supun si omul si cimpanezul, ei vor deveni din ce in ce mai indepartati. Cum se vede interpetarile dvs sint scolastice, banale si lipsite de cunostintele de baza in domeniul genetic si al biologiei.E si firesc sa fie asa dupa cum aglomerati toate cunostintele intr-un caleidoscop pseudo-stiintific sub Dumnezeul dvs Hardabagy Lazlo cel atoate stiutorul din care ne-ati citit ca dintr-o Biblie.
Acuma ca Hardabagy Lazlo asta ilustru anonim necunoscut poate nici pe ulita pe care s-a nascut, va place la nebunie am inteles noi dupa cum ni l-ati cintat mai ceva ca un popa calvinist.Numai ca n-am inteles de ce nu cititi si alceva.Va dau un exemplu aici si in ce priveste interpetarea religie-stiinta sint de acord ca un dobitoc pseudo-stiintific care se 'adapa' din reviste si ziare fara baza stiintifica necesara nu poate intelege substratul subiectului complex al religiei si tinde sa-l confunde cu masa pe care scrie pentru ca n-a ajuns sa gindesca nici macar la nivelul de elev de liceu care a intilnit notiunea de numar complex format din parte reala si parte imaginara.Prilej de prime intrebari pornind de la numere cum alta data au facut in alte conditii Pitagoreicii.Ca sa vedeti ca si 25 de secole in urma gindirea umana avea mai multe valente decit interpetarile dvs. anoste, insipide, inguste si unilaterale. Still Evolving, Human Genes Tell New Story http://www.nytimes.com/2006/03/07/science/07evolve.html? _r=1&pagewanted=all&oref=slogin Still Evolving, Human Genes Tell New Story Peter Thompson for The New York TimesDr. Jonathan Pritchard writing an equation to scan the human genome for signs of natural selection Monday at the University of Chicago. By NICHOLAS WADE Published: March 7, 2006 Providing the strongest evidence yet that humans are still evolving, researchers have detected some 700 regions of the human genome where genes appear to have been reshaped by natural selection, a principal force of evolution, within the last 5,000 to 15,000 years. The genes that show this evolutionary change include some responsible for the senses of taste and smell, digestion, bone structure, skin color and brain function. Many of these instances of selection may reflect the pressures that came to bear as people abandoned their hunting and gathering way of life for settlement and agriculture, a transition well under way in Europe and East Asia some 5,000 years ago. Under natural selection, beneficial genes become more common in a population as their owners have more progeny. Three populations were studied, Africans, East Asians and Europeans. In each, a mostly different set of genes had been favored by natural selection. The selected genes, which affect skin color, hair texture and bone structure, may underlie the present-day differences in racial appearance. The study of selected genes may help reconstruct many crucial events in the human past. It may also help physical anthropologists explain why people over the world have such a variety of distinctive appearances, even though their genes are on the whole similar, said Dr. Spencer Wells, director of the Genographic Project of the National Geographic Society. The finding adds substantially to the evidence that human evolution did not grind to a halt in the distant past, as is tacitly assumed by many social scientists. Even evolutionary psychologists, who interpret human behavior in terms of what the brain evolved to do, hold that the work of natural selection in shaping the human mind was completed in the pre-agricultural past, more than 10,000 years ago. "There is ample evidence that selection has been a major driving point in our evolution during the last 10,000 years, and there is no reason to suppose that it has stopped," said Jonathan Pritchard, a population geneticist at the University of Chicago who headed the study. Dr. Pritchard and his colleagues, Benjamin Voight, Sridhar Kudaravalli and Xiaoquan Wen, report their findings in today's issue of PLOS-Biology. Their data is based on DNA changes in three populations gathered by the HapMap project, which built on the decoding of the human genome in 2003. The data, though collected to help identify variant genes that contribute to disease, also give evidence of evolutionary change. The fingerprints of natural selection in DNA are hard to recognize. Just a handful of recently selected genes have previously been identified, like those that confer resistance to malaria or the ability to digest lactose in adulthood, an adaptation common in Northern Europeans whose ancestors thrived on cattle milk. But the authors of the HapMap study released last October found many other regions where selection seemed to have occurred, as did an analysis published in December by Robert K. Moysis of the University of California, Irvine. Dr. Pritchard's scan of the human genome differs from the previous two because he has developed a statistical test to identify just genes that have started to spread through populations in recent millennia and have not yet become universal, as many advantageous genes eventually do. The selected genes he has detected fall into a handful of functional categories, as might be expected if people were adapting to specific changes in their environment. Some are genes involved in digesting particular foods like the lactose-digesting gene common in Europeans. Some are genes that mediate taste and smell as well as detoxify plant poisons, perhaps signaling a shift in diet from wild foods to domesticated plants and animals. Dr. Pritchard estimates that the average point at which the selected genes started to become more common under the pressure of natural selection is 10,800 years ago in the African population and 6,600 years ago in the Asian and European populations. Dr. Richard G. Klein, a paleoanthropologist at Stanford, said that it was hard to correlate the specific gene changes in the three populations with events in the archaeological record, but that the timing and nature of the changes in the East Asians and Europeans seemed compatible with the shift to agriculture. Rice farming became widespread in China 6,000 to 7,000 years ago, and agriculture reached Europe from the Near East around the same time. Skeletons similar in form to modern Chinese are hard to find before that period, Dr. Klein said, and there are few European skeletons older than 10,000 years that look like modern Europeans. That suggests that a change in bone structure occurred in the two populations, perhaps in connection with the shift to agriculture. Dr. Pritchard's team found that several genes associated with embryonic development of the bones had been under selection in East Asians and Europeans, and these could be another sign of the forager-to-farmer transition, Dr. Klein said. Dr. Wells, of the National Geographic Society, said Dr. Pritchard's results were fascinating and would help anthropologists explain the immense diversity of human populations even though their genes are generally similar. The relative handful of selected genes that Dr. Pritchard's study has pinpointed may hold the answer, he said, adding, "Each gene has a story of some pressure we adapted to." Dr. Wells is gathering DNA from across the globe to map in finer detail the genetic variation brought to light by the HapMap project. Dr. Pritchard's list of selected genes also includes five that affect skin color. The selected versions of the genes occur solely in Europeans and are presumably responsible for pale skin. Anthropologists have generally assumed that the first modern humans to arrive in Europe some 45,000 years ago had the dark skin of their African origins, but soon acquired the paler skin needed to admit sunlight for vitamin D synthesis. The finding of five skin genes selected 6,600 years ago could imply that Europeans acquired their pale skin much more recently. Or, the selected genes may have been a reinforcement of a process established earlier, Dr. Pritchard said. The five genes show no sign of selective pressure in East Asians. Because Chinese and Japanese are also pale, Dr. Pritchard said, evolution must have accomplished the same goal in those populations by working through different genes or by changing the same genes but many thousands of years before, so that the signal of selection is no longer visible to the new test. Dr. Pritchard also detected selection at work in brain genes, including a group known as microcephaly genes because, when disrupted, they cause people to be born with unusually small brains. Dr. Bruce Lahn, also of the University of Chicago, theorizes that successive changes in the microcephaly genes may have enabled the brain to enlarge in primate evolution, a process that may have continued in the recent human past. Last September, Dr. Lahn reported that one microcephaly gene had recently changed in Europeans and another in Europeans and Asians. He predicted that other brain genes would be found to have changed in other populations. Dr. Pritchard's test did not detect a signal of selection in Dr. Lahn's two genes, but that may just reflect limitations of the test, he and Dr. Lahn said. Dr. Pritchard found one microcephaly gene that had been selected for in Africans and another in Europeans and East Asians. Another brain gene, SNTG1, was under heavy selection in all three populations. "It seems like a really interesting gene, given our results, but there doesn't seem to be that much known about exactly what it's doing to the brain," Dr. Pritchard said. Dr. Wells said that it was not surprising the brain had continued to evolve along with other types of genes, but that nothing could be inferred about the nature of the selective pressure until the function of the selected genes was understood. The four populations analyzed in the HapMap project are the Yoruba of Nigeria, Han Chinese from Beijing, Japanese from Tokyo and a French collection of Utah families of European descent. The populations are assumed to be typical of sub-Saharan Africa, East Asia and Europe, but the representation, though presumably good enough for medical studies, may not be exact. Dr. Pritchard's test for selection rests on the fact that an advantageous mutation is inherited along with its gene and a large block of DNA in which the gene sits. If the improved gene spreads quickly, the DNA region that includes it will become less diverse across a population because so many people now carry the same sequence of DNA units at that location. Dr. Pritchard's test measures the difference in DNA diversity between those who carry a new gene and those who do not, and a significantly lesser diversity is taken as a sign of selection. The difference disappears when the improved gene has swept through the entire population, as eventually happens, so the test picks up only new gene variants on their way to becoming universal. The selected genes turned out to be quite different from one racial group to another. Dr. Pritchard's test identified 206 regions of the genome that are under selection in the Yorubans, 185 regions in East Asians and 188 in Europeans. The few overlaps between races concern genes that could have been spread by migration or else be instances of independent evolution, Dr. Pritchard said. Parerea mea este ca stiinta si credinta sunt doua domenii totalmente diferite. Stiinta este rezultatul nu doar al "creatiei intelectuale" ci si al testarii teoriilor in practica. In stiinta, degeaba "crezi ceva", mai este nevoie si de date concrete care sa sustina "adevarul tau" in fata "parerii altora". In subdomeniul stiintific care se ocupa de studierea stiintifica a originii omului, nu este indeajuns sa se doreasca a se afirma ca omul provine din maimute, ci mai trebuie si "date ale experientei". Anatomie comparata, paleontologie, genetica, fiziologie comparata etc etc. Eu personal, daca vad o gorila, si daca apoi ma uit la mine, in oglinda, nu prea vad diferente semnificative, atat de mari incat sa imi pun cat de cat serios problema ca am avea o origine filogenetica diferita, atat de diferita incat acela sa fie animal, iar eu o creatie a unei divinitati care m-a facut pe chipul si asemanarea sa. Daca imi numar degetele, daca ma uit la unghii, la dispunerea si diferentierea dentitiei, la oase, de la vertebre la falange si la cele care imi compun craniul, nu vad decat o diferenta de detalii nesemnificative. Daca ma uit la globulele din sange, la lobii pulmonari, la structura inimii sau a rinichilor, la lobii encefalului, la structura pielii si a firelor de par, la ochi si la iris, la stomac si la duoden, la glandele endocrine si la puiul alaptat la san, nu vad decat diferente de detalii. Orice as analiza, nu vad decat diferente de detalii. Materialul genetic uman se suprapune peste 99% cu cel al maimutelor antropoide, ceea ce cred ca trebuie sa dea de gandit oricarui bigot. Faptul ca speciile inrudite apropiat pot avea un numar diferit de cromosomi, este desigur "la mintea cocosului". Chiar si specii din acelasi gen, au cariotipuri diferite, rearanjari ale materialului genetic in cadrul cromosomilor, etc, aceste deosebiri ale detaliilor fiind parte a diferentelor dintre "specii". Desigur, un biolog care intelege cat de cat evolutia, stie ca pana si termenul de "specie" este o "realitate virtuala", o incercare a omului de "a pune in ordine" ceea ce vede in jurul sau. In realitate "speciile" sunt fragmentate in subspecii sau "rase locale", mai mult sau mai putin inrudite intre ele, unele putand avea urmasi fertili intre ele, altele avand grade crescute de incompatibilitate genetica, pana la comportarea ca specii diferite. Spre exemplu, daca o "specie?" are populatiile A, B, C, D, E, F, G, H, I, J, K, asezate sub forma de semicerc, sa zicem pe niste insule, iar A si B produc urmasi fertili, la fel, B cu C si asa mai departe, insa A si K, daca ajung impreuna (sa zicem ca "cercul se inchide"), prezinta diferente atat de mari, incat se comporta ca "specii" diferite... Ma intreb atunci, ce este in cazul de fata, o specie, doua, si unde anume este limita intre ele? Desigur, vedem ca termenul in sine este o chestiune necesara noua pentru a putea "ordona natura" in cartile simple de biologie, sau pentru colectionarii de timbre... Daca avem curiozitatea naturala, "sa nu ramanem nestiutori de carte stiintifica", si ajungem macar sa citim presa la nivel de jurnale credibile, sa vedem spre exemplu un articol din Washington Post, din 18 mai 2006, putem vedea ca data de despartire a cimpanzeului de om este estimata, pe baze genetice (precum si pe baze fosile) la circa 6,3 milioane de ani in urma, dar pare ca 'cimpanzeii' si 'oamenii' se mai distrau impreuna pana in urma cu circa 1,2 milioane de ani in urma, cand separatia a fost mai profunda. Deci, unde este acea urisa diferenta, ca am veni din locuri diferite? http://www.washingtonpost.com/wp-dyn/content/article/2006/05/17/AR2006051702158.html Ori daca citim articolul de la la: http://www.uchicago.edu/aff/mwc-amacad/biocomplexity/conference_papers/goodman.pdf#search=%22human%20monkey%20genetics%22 putem vedea ca ADNul functional al omului si al cimpanzeilor arata ca ei sunt mai asemanatori unul fata de celalalt, decat este oricare dintre ei fata de alte specii de maimute antropide. Dar, desigur aceste chestii nu au nici o valoare atat timp cat traiesti in sfera "crede si nu cerceta", cat timp in scoala, de mic copil esti indoctrinat ca un dobitoc de preoti care "stiu Adevarul", si cat timp ai "dorinte sexuale permanente". 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