| Michigan Science Curriculum; We want your feedback...NOT | |
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| Tweet Topic Started: Sep 13 2006, 06:41 AM (3,026 Views) | |
| fyi | Sep 16 2006, 10:14 PM Post #31 |
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Vatican astronomer joins evolution debate Intelligent design isn’t science, ‘though it pretends to be,’ he says http://www.msnbc.msn.com/id/10101394/ Updated: 3:12 p.m. PT Nov 18, 2005 VATICAN CITY - The Vatican's chief astronomer said Friday that "intelligent design" isn't science and doesn't belong in science classrooms, the latest high-ranking Roman Catholic official to enter the evolution debate in the United States. The Rev. George Coyne, the Jesuit director of the Vatican Observatory, said placing intelligent design theory alongside that of evolution in school programs was "wrong" and was akin to mixing apples with oranges. "Intelligent design isn't science even though it pretends to be," the ANSA news agency quoted Coyne as saying on the sidelines of a conference in Florence. "If you want to teach it in schools, intelligent design should be taught when religion or cultural history is taught, not science." His comments were in line with his previous statements on intelligent design — whose supporters say the universe is so complex that it must have been created by a higher power. Proponents of intelligent design are seeking to get public schools in the United States to teach it as part of the science curriculum. Critics say intelligent design is merely creationism — a literal reading of the Bible's story of creation — camouflaged in scientific language, and they say it does not belong in science curriculum. Moving away from a ‘designer God’ In a June article in the British Catholic magazine The Tablet, Coyne reaffirmed God's role in creation, but said science explains the history of the universe. "If they respect the results of modern science, and indeed the best of modern biblical research, religious believers must move away from the notion of a dictator God or a designer God, a Newtonian God who made the universe as a watch that ticks along regularly." Rather, he argued, God should be seen more as an encouraging parent. "God in his infinite freedom continuously creates a world that reflects that freedom at all levels of the evolutionary process to greater and greater complexity," he wrote. "He is not continually intervening, but rather allows, participates, loves." The Vatican Observatory, which Coyne heads, is one of the oldest astronomical research institutions in the world. It is based in the papal summer residence at Castel Gandolfo south of Rome. Other voices Last week, Pope Benedict XVI waded indirectly into the evolution debate by saying the universe was made by an "intelligent project" and criticizing those who in the name of science say its creation was without direction or order. Questions about the Vatican's position on evolution were raised in July by Austrian Cardinal Christoph Schoenborn. In a New York Times column, Schoenborn seemed to back intelligent design and dismissed a 1996 statement by Pope John Paul II that evolution was "more than just a hypothesis." At that time, Schoenborn said the late pope's statement was "rather vague and unimportant." Later, however, Schoenborn paid tribute to Charles Darwin's theories and said the controversy over his remarks was due to a misunderstanding. |
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| fyi | Sep 16 2006, 10:21 PM Post #32 |
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Einstein and Darwin: A tale of two theories Q&A with ‘Origins’ astronomer Neil deGrasse Tyson http://www.msnbc.msn.com/id/7159345/ By Alan Boyle Science editor MSNBC Updated: 3:00 p.m. PT May 2, 2005 SEATTLE - One scientist came up with a new way of explaining how biology works. A generation later, the other one came up with a new way of explaining how physics works. Today, after a century of scrutiny, both explanations still pretty much hold up. But in popular culture, physicist Albert Einstein is idolized, while biologist Charles Darwin's legacy is clouded with controversy. Why do Darwin's theories on the origin of species, put forth in 1859, hold a status so different from that of Einstein's theories on relativity, published between 1905 and 1916? Astrophysicist Neil deGrasse Tyson, director of New York's Hayden Planetarium and co-author of the book "Origins: Fourteen Billion Years of Cosmic Evolution," reflected on that question during a recent interview at the University of Washington. Here's an edited question-and-answer transcript of the interview: MSNBC: Einstein and Darwin seem to hold two different places in our society. One is virtually a pop culture icon, while some people almost want to take down the other guy's statues. Why is that we have two different approaches to these people, even though they developed theories that are in very similar states of evidence? Neil deGrasse Tyson: While they were both scientists, Einstein was the first very public scientist who was visibly active in social causes as well as political causes. I don’t know that the same was true with Darwin. I know he was well known in his day. I know his book, "On the Origin of Species," was a best seller. But I don’t know that he was active in politics, influencing governments. I don’t know that he was approached by a sovereign nation and was asked to be its president, as Einstein was with the new state of Israel, for example. As a citizen, as a public scientist, I can tell you that Einstein essentially overturned a so strongly established paradigm of science, whereas Darwin didn’t really overturn a science paradigm. There was a paradigm there, but it was a gradual process: “Does evolution work as Lamarck said, with the inheritance of acquired traits? No, it doesn’t” … You can see the evolution of an idea there, settling on what works, whereas Einstein took Newtonian physics and said this is incomplete, which is something that was unimaginable for the hundreds of years that we were doing Newtonian physics. My read of history is that people wanted to get opinions on everything from someone who was so widely recognized as being so smart. It’s kind of like the situation with rock stars today: You want to know what Bono thinks about global hunger, even though he made his money as a musician. Exactly. So Einstein is not necessarily an expert in these other fields. Not even necessarily informed in these other fields. But people know that he’s a deep thinker. So what are his deep thoughts about Jews and Arabs, and the civil rights movement, and the bomb, and Nazi Germany? He became this sounding board for people to try to get some point of view from someone they implicitly trust, from a smart person. David Friedman / MSNBC.com Neil deGrasse Tyson, director of the Hayden Planetarium and co-author of the book "Origins," says it's simply a matter of time before the fundamentals of evolutionary biology are as widely accepted as the fundamentals of relativistic physics. -------------------------------------------------------------------------------- So there’s that factor that distinguishes Einstein from Darwin. But I think there’s a stronger factor: There is no science in this world like physics. Nothing comes close to the precision with which physics enables you to understand the world around you. It’s the laws of physics that allow us to say exactly what time the sun is going to rise. What time the eclipse is going to begin. What time the eclipse is going to end. What time the meteor is going to hit. Do you remember when David Levy and Carolyn and Gene Shoemaker discovered a comet, and they had a few measurements of it, and they said, ‘The next time around, it’s going to slam into Jupiter.’ And what’s remarkable is that no one questions that. Because they know it is the powers of understanding, derived from the fundamentals of physics, that give you that capacity to basically predict the future with high precision. Biology doesn’t do that. Chemistry doesn’t do that. You can predict reactions, yes. You can get an understanding of how things work, yes. Darwin’s theory of evolution is a framework by which we understand the diversity of life on Earth. But there is no equation sitting there in Darwin’s “Origin of Species” that you apply and say, “What is this species going to look like in 100 years or 1,000 years?” Biology isn’t there yet with that kind of predictive precision. So, when we speak of the theory of relativity, and the theory of evolution, they are each extremely important ways of understanding the world. But the tool kit that comes with the relativity theory, that comes with any physics theory, has a level of precision that puts it just in another category. It’s not simply an organizing principle. When you predict that the sun is going to rise at 7:22 tomorrow morning, and someone wants to debate you … you’re going to be wasting your time having that conversation. Just walk away from it, because you know in advance what’s going to happen. For that reason, Darwin’s theory of evolution, because it’s a theory of biology, because biology is a different kind of science from physics, it looks to the outsider as if you can just jump in and claim that things are just not what the biologist sees them to be. Now of course that’s false, but I’m just submitting to you that when you have your tool kit of predictive powers, that’s kind of like an armor at the perimeter. You’re not going to get past that to say that somehow that equation is wrong. The equation is demonstrably correct, so go home. |
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| fyi | Sep 16 2006, 11:24 PM Post #33 |
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[size=7]Board Puts Politics Ahead of Science[/size] September 14, 2006 Detroit Free Press http://www.freep.com/apps/pbcs.dll/article...29/1068/OPINION The Michigan State Board of Education has done a disservice to science and to high school science teachers by delaying adoption of the science portion of Michigan's new requirements for high school graduation. The board voted 6-2 Tuesday in favor of a delay requested by state legislators who are pushing faith-based alternatives to the theory of evolution. This is just another attempt to keep a door open to teaching creationism or intelligent design. The board should have closed it, as science teachers requested. Board members get elected to make decisions, not to defer to political pressure. The delay was requested by the chairs of the House and Senate Education Committees to accommodate Republican state Reps. Jack Hoogendyk of Kalamazoo and John Moolenaar of Midland, who want a key wording change inserted into the policy. As it stands, the policy directs that teachers demonstrate how fossil records, comparative anatomy and other evidence "may" corroborate the theory of evolution. Hoogendyk and Moolenaar are pushing to have the words read "may or may not." Sounds innocuous, but this is really about injecting faith and beliefs into science. Michigan's new curriculum is supposed to set tough guidelines, not try to spoon-feed an ideology to students. Teachers who are allowed to, will, no doubt instruct students in the value of thinking about science broadly and asking critical questions. By deferring even this much to the legislators, the state board has essentially given science teachers a vote of no confidence and deprived them of a chance to collaborate on classroom strategies. That's because the board won't vote until Oct. 10, and the science curriculum guidelines were supposed to be in place by an Oct. 3 statewide conference for teachers on Earth science, biology, chemistry and physics. The conference will now use draft guidelines while the state board decides whether politics is going to figure in the final version. |
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| cmic | Sep 17 2006, 08:02 AM Post #34 |
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The article from the vatican is exactly what I was trying to say earlier. I did it poorly, but this is what I meant. I believe the Catholic Church has a good stance on it. Let's not mix science and religion or pretend to teach one as another. Science isn't a religion and shouldn't be taught as such nor is religion a science and shouldn't be taught as such. If creationism is to be taught in school then religion must be and prayer should be accepted and let's bring back Christmas and Easter parties too. God has been erased from public school education. The religion we teach in public schools now is political secularism. "Intelligent design isn't science even though it pretends to be," the ANSA news agency quoted Coyne as saying on the sidelines of a conference in Florence. "If you want to teach it in schools, intelligent design should be taught when religion or cultural history is taught, not science." |
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| jodygirlh | Sep 17 2006, 09:51 AM Post #35 |
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This is certainly a topic that can be difficult to discuss, but I (for once) agree with Corwin. Evolution cannot be proven anymore than creation can be. I disagree that the 'research and evidence' likens it to the theory of gravity or light--and therefore we should teach it in the classroom. Sorry, but I long for the times when we taught morality and old-fashioned values in the classroom. The absence of God in the schools in favor of political correctness, is just one more step in the wrong direction--IMO. Okay enough said by me---don't wish to offend either. |
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| SJC | Sep 17 2006, 09:52 AM Post #36 |
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Those aren't theories. Technically, they're hypothesis. A hypothesis is just an idea that someone sets about to prove. It’s not considered a theory until it’s proven independently at least twice. I don't think anyone can prove that |
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| fyi | Sep 17 2006, 10:15 AM Post #37 |
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What is the difference between a fact, a theory and a hypothesis? In popular usage, a theory is just a vague and fuzzy sort of fact and a hypothesis is often used as a fancy synonym to `guess'. But to a scientist a theory is a conceptual framework that explains existing observations and predicts new ones. For instance, suppose you see the Sun rise. This is an existing observation which is explained by the theory of gravity proposed by Newton. This theory, in addition to explaining why we see the Sun move across the sky, also explains many other phenomena such as the path followed by the Sun as it moves (as seen from Earth) across the sky, the phases of the Moon, the phases of Venus, the tides, just to mention a few. You can today make a calculation and predict the position of the Sun, the phases of the Moon and Venus, the hour of maximal tide, all 200 years from now. The same theory is used to guide spacecraft all over the Solar System. A hypothesis is a working assumption. Typically, a scientist devises a hypothesis and then sees if it ``holds water'' by testing it against available data (obtained from previous experiments and observations). If the hypothesis does hold water, the scientist declares it to be a theory. -------------------------------------------------------------------------------- |
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| fyi | Sep 17 2006, 11:46 AM Post #38 |
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http://newton.nap.edu/html/creationism/evidence.html Evidence Supporting Biological Evolution A long path leads from the origins of primitive "life," which existed at least 3.5 billion years ago, to the profusion and diversity of life that exists today. This path is best understood as a product of evolution. Contrary to popular opinion, neither the term nor the idea of biological evolution began with Charles Darwin and his foremost work, On the Origin of Species by Means of Natural Selection (1859). Many scholars from the ancient Greek philosophers on had inferred that similar species were descended from a common ancestor. The word "evolution" first appeared in the English language in 1647 in a nonbiological connection, and it became widely used in English for all sorts of progressions from simpler beginnings. The term Darwin most often used to refer to biological evolution was "descent with modification," which remains a good brief definition of the process today. Darwin proposed that evolution could be explained by the differential survival of organisms following their naturally occurring variation--a process he termed "natural selection." According to this view, the offspring of organisms differ from one another and from their parents in ways that are heritable--that is, they can pass on the differences genetically to their own offspring. Furthermore, organisms in nature typically produce more offspring than can survive and reproduce given the constraints of food, space, and other environmental resources. If a particular off spring has traits that give it an advantage in a particular environment, that organism will be more likely to survive and pass on those traits. As differences accumulate over generations, populations of organisms diverge from their ancestors. Darwin's original hypothesis has undergone extensive modification and expansion, but the central concepts stand firm. Studies in genetics and molecular biology--fields unknown in Darwin's time--have explained the occurrence of the hereditary variations that are essential to natural selection. Genetic variations result from changes, or mutations, in the nucleotide sequence of DNA, the molecule that genes are made from. Such changes in DNA now can be detected and described with great precision. Genetic mutations arise by chance. They may or may not equip the organism with better means for surviving in its environment. But if a gene variant improves adaptation to the environment (for example, by allowing an organism to make better use of an available nutrient, or to escape predators more effectively--such as through stronger legs or disguising coloration), the organisms carrying that gene are more likely to survive and reproduce than those without it. Over time, their descendants will tend to increase, changing the average characteristics of the population. Although the genetic variation on which natural selection works is based on random or chance elements, natural selection itself produces "adaptive" change--the very opposite of chance. Scientists also have gained an understanding of the processes by which new species originate. A new species is one in which the individuals cannot mate and produce viable descendants with individuals of a preexisting species. The split of one species into two often starts because a group of individuals becomes geographically separated from the rest. This is particularly apparent in distant remote islands, such as the Galápagos and the Hawaiian archipelago, whose great distance from the Americas and Asia means that arriving colonizers will have little or no opportunity to mate with individuals remaining on those continents. Mountains, rivers, lakes, and other natural barriers also account for geographic separation between populations that once belonged to the same species. Once isolated, geographically separated groups of individuals become genetically differentiated as a consequence of mutation and other processes, including natural selection. The origin of a species is often a gradual process, so that at first the reproductive isolation between separated groups of organisms is only partial, but it eventually becomes complete. Scientists pay special attention to these intermediate situations, because they help to reconstruct the details of the process and to identify particular genes or sets of genes that account for the reproductive isolation between species. A particularly compelling example of speciation involves the 13 species of finches studied by Darwin on the Galápagos Islands, now known as Darwin's finches. The ancestors of these finches appear to have emigrated from the South American mainland to the Galápagos. Today the different species of finches on the island have distinct habitats, diets, and behaviors, but the mechanisms involved in speciation continue to operate. A research group led by Peter and Rosemary Grant of Princeton University has shown that a single year of drought on the islands can drive evolutionary changes in the finches. Drought diminishes supplies of easily cracked nuts but permits the survival of plants that produce larger, tougher nuts. Droughts thus favor birds with strong, wide beaks that can break these tougher seeds, producing populations of birds with these traits. The Grants have estimated that if droughts occur about once every 10 years on the islands, a new species of finch might arise in only about 200 years. The following sections consider several aspects of biological evolution in greater detail, looking at paleontology, comparative anatomy, biogeography, embryology, and molecular biology for further evidence supporting evolution. The Fossil Record Although it was Darwin, above all others, who first marshaled convincing evidence for biological evolution, earlier scholars had recognized that organisms on Earth had changed systematically over long periods of time. For example, in 1799 an engineer named William Smith reported that, in undisrupted layers of rock, fossils occurred in a definite sequential order, with more modern-appearing ones closer to the top. Because bottom layers of rock logically were laid down earlier and thus are older than top layers, the sequence of fossils also could be given a chronology from oldest to youngest. His findings were confirmed and extended in the 1830s by the paleontologist William Lonsdale, who recognized that fossil remains of organisms from lower strata were more primitive than the ones above. Today, many thousands of ancient rock deposits have been identified that show corresponding successions of fossil organisms. Thus, the general sequence of fossils had already been recognized before Darwin conceived of descent with modification. But the paleontologists and geologists before Darwin used the sequence of fossils in rocks not as proof of biological evolution, but as a basis for working out the original sequence of rock strata that had been structurally disturbed by earthquakes and other forces. In Darwin's time, paleontology was still a rudimentary science. Large parts of the geological succession of stratified rocks were unknown or inadequately studied. Darwin, therefore, worried about the rarity of intermediate forms between some major groups of organisms. Today, many of the gaps in the paleontological record have been filled by the research of paleontologists. Hundreds of thousands of fossil organisms, found in well-dated rock sequences, represent successions of forms through time and manifest many evolutionary transitions. As mentioned earlier, microbial life of the simplest type was already in existence 3.5 billion years ago. The oldest evidence of more complex organisms (that is, eucaryotic cells, which are more complex than bacteria) has been discovered in fossils sealed in rocks approximately 2 billion years old. Multicellular organisms, which are the familiar fungi, plants, and animals, have been found only in younger geological strata. The following list presents the order in which increasingly complex forms of life appeared: -------------------------------------------------------------------------------- Life Form -------------------------------------------------------------------------------- Millions of Years Since First Known Appearance (Approximate) -------------------------------------------------------------------------------- Microbial (procaryotic cells) 3,500 Complex (eucaryotic cells) 2,000 First multicellular animals 670 Shell-bearing animals 540 Vertebrates (simple fishes) 490 Amphibians 350 Reptiles 310 Mammals 200 Nonhuman primates 60 Earliest apes 25 Australopithecine ancestors of humans 4 Modern humans 0 .15 (150,000 years) -------------------------------------------------------------------------------- So many intermediate forms have been discovered between fish and amphibians, between amphibians and reptiles, between reptiles and mammals, and along the primate lines of descent that it often is difficult to identify categorically when the transition occurs from one to another particular species. Actually, nearly all fossils can be regarded as intermediates in some sense; they are life forms that come between the forms that preceded them and those that followed. The fossil record thus provides consistent evidence of systematic change through time--of descent with modification. From this huge body of evidence, it can be predicted that no reversals will be found in future paleontological studies. That is, amphibians will not appear before fishes, nor mammals before reptiles, and no complex life will occur in the geological record before the oldest eucaryotic cells. This prediction has been upheld by the evidence that has accumulated until now: no reversals have been found. Common Structures Inferences about common descent derived from paleontology are reinforced by comparative anatomy. For example, the skeletons of humans, mice, and bats are strikingly similar, despite the different ways of life of these animals and the diversity of environments in which they flourish. The correspondence of these animals, bone by bone, can be observed in every part of the body, including the limbs; yet a person writes, a mouse runs, and a bat flies with structures built of bones that are different in detail but similar in general structure and relation to each other. Scientists call such structures homologies and have concluded that they are best explained by common descent. Comparative anatomists investigate such homologies, not only in bone structure but also in other parts of the body, working out relationships from degrees of similarity. Their conclusions provide important inferences about the details of evolutionary history, inferences that can be tested by comparisons with the sequence of ancestral forms in the paleontological record. The mammalian ear and jaw are instances in which paleontology and comparative anatomy combine to show common ancestry through transitional stages. The lower jaws of mammals contain only one bone, whereas those of reptiles have several. The other bones in the reptile jaw are homologous with bones now found in the mammalian ear. Paleontologists have discovered intermediate forms of mammal-like reptiles (Therapsida) with a double jaw joint--one composed of the bones that persist in mammalian jaws, the other consisting of bones that eventually became the hammer and anvil of the mammalian ear. The Distribution of Species Biogeography also has contributed evidence for descent from common ancestors. The diversity of life is stupendous. Approximately 250,000 species of living plants, 100,000 species of fungi, and one million species of animals have been described and named, each occupying its own peculiar ecological setting or niche; and the census is far from complete. Some species, such as human beings and our companion the dog, can live under a wide range of environments. Others are amazingly specialized. One species of a fungus (Laboulbenia) grows exclusively on the rear portion of the covering wings of a single species of beetle (Aphaenops cronei) found only in some caves of southern France. The larvae of the fly Drosophila carcinophila can develop only in specialized grooves beneath the flaps of the third pair of oral appendages of a land crab that is found only on certain Caribbean islands. How can we make intelligible the colossal diversity of living beings and the existence of such extraordinary, seemingly whimsical creatures as the fungus, beetle, and fly described above? And why are island groups like the Galápagos so often inhabited by forms similar to those on the nearest mainland but belonging to different species? Evolutionary theory explains that biological diversity results from the descendants of local or migrant predecessors becoming adapted to their diverse environments. This explanation can be tested by examining present species and local fossils to see whether they have similar structures, which would indicate how one is derived from the other. Also, there should be evidence that species without an established local ancestry had migrated into the locality. Wherever such tests have been carried out, these conditions have been confirmed. A good example is provided by the mammalian populations of North and South America, where strikingly different native organisms evolved in isolation until the emergence of the isthmus of Panama approximately 3 million years ago. Thereafter, the armadillo, porcupine, and opossum--mammals of South American origin--migrated north, along with many other species of plants and animals, while the mountain lion and other North American species made their way across the isthmus to the south. The evidence that Darwin found for the influence of geographical distribution on the evolution of organisms has become stronger with advancing knowledge. For example, approximately 2,000 species of flies belonging to the genus Drosophila are now found throughout the world. About one-quarter of them live only in Hawaii. More than a thousand species of snails and other land mollusks also are found only in Hawaii. The biological explanation for the multiplicity of related species in remote localities is that such great diversity is a consequence of their evolution from a few common ancestors that colonized an isolated environment. The Hawaiian Islands are far from any mainland or other islands, and on the basis of geological evidence they never have been attached to other lands. Thus, the few colonizers that reached the Hawaiian Islands found many available ecological niches, where they could, over numerous generations, undergo evolutionary change and diversification. No mammals other than one bat species lived in the Hawaiian Islands when the first human settlers arrived; similarly, many other kinds of plants and animals were absent. The Hawaiian Islands are not less hospitable than other parts of the world for the absent species. For example, pigs and goats have multiplied in the wild in Hawaii, and other domestic animals also thrive there. The scientific explanation for the absence of many kinds of organisms, and the great multiplication of a few kinds, is that many sorts of organisms never reached the islands, because of their geographic isolation. Those that did reach the islands diversified over time because of the absence of related organisms that would compete for resources. Similarities During Development Embryology, the study of biological development from the time of conception, is another source of independent evidence for common descent. Barnacles, for instance, are sedentary crustaceans with little apparent similarity to such other crustaceans as lobsters, shrimps, or copepods. Yet barnacles pass through a free-swimming larval stage in which they look like other crustacean larvae. The similarity of larval stages supports the conclusion that all crustaceans have homologous parts and a common ancestry. Similarly, a wide variety of organisms from fruit flies to worms to mice to humans have very similar sequences of genes that are active early in development. These genes influence body segmentation or orientation in all these diverse groups. The presence of such similar genes doing similar things across such a wide range of organisms is best explained by their having been present in a very early common ancestor of all of these groups. New Evidence from Molecular Biology The unifying principle of common descent that emerges from all the foregoing lines of evidence is being reinforced by the discoveries of modern biochemistry and molecular biology. The code used to translate nucleotide sequences into amino acid sequences is essentially the same in all organisms. Moreover, proteins in all organisms are invariably composed of the same set of 20 amino acids. This unity of composition and function is a powerful argument in favor of the common descent of the most diverse organisms. In 1959, scientists at Cambridge University in the United Kingdom determined the three-dimensional structures of two proteins that are found in almost every multicelled animal: hemoglobin and myoglobin. Hemoglobin is the protein that carries oxygen in the blood. Myoglobin receives oxygen from hemoglobin and stores it in the tissues until needed. These were the first three-dimensional protein structures to be solved, and they yielded some key insights. Myoglobin has a single chain of 153 amino acids wrapped around a group of iron and other atoms (called "heme") to which oxygen binds. Hemoglobin, in contrast, is made of up four chains: two identical chains consisting of 141 amino acids, and two other identical chains consisting of 146 amino acids. However, each chain has a heme exactly like that of myoglobin, and each of the four chains in the hemoglobin molecule is folded exactly like myoglobin. It was immediately obvious in 1959 that the two molecules are very closely related. During the next two decades, myoglobin and hemoglobin sequences were determined for dozens of mammals, birds, reptiles, amphibians, fish, worms, and molluscs. All of these sequences were so obviously related that they could be compared with confidence with the three-dimensional structures of two selected standards--whale myoglobin and horse hemoglobin. Even more significantly, the differences between sequences from different organisms could be used to construct a family tree of hemoglobin and myoglobin variation among organisms. This tree agreed completely with observations derived from paleontology and anatomy about the common descent of the corresponding organisms. Similar family histories have been obtained from the three-dimensional structures and amino acid sequences of other proteins, such as cytochrome c (a protein engaged in energy transfer) and the digestive proteins trypsin and chymotrypsin. The examination of molecular structure offers a new and extremely powerful tool for studying evolutionary relationships. The quantity of information is potentially huge--as large as the thousands of different proteins contained in living organisms, and limited only by the time and resources of molecular biologists. As the ability to sequence the nucleotides making up DNA has improved, it also has become possible to use genes to reconstruct the evolutionary history of organisms. Because of mutations, the sequence of nucleotides in a gene gradually changes over time. The more closely related two organisms are, the less different their DNA will be. Because there are tens of thousands of genes in humans and other organisms, DNA contains a tremendous amount of information about the evolutionary history of each organism. Genes evolve at different rates because, although mutation is a random event, some proteins are much more tolerant of changes in their amino acid sequence than are other proteins. For this reason, the genes that encode these more tolerant, less constrained proteins evolve faster. The average rate at which a particular kind of gene or protein evolves gives rise to the concept of a "molecular clock." Molecular clocks run rapidly for less constrained proteins and slowly for more constrained proteins, though they all time the same evolutionary events. The figure on this page compares three molecular clocks: for cytochrome c proteins, which interact intimately with other macromolecules and are quite constrained in their amino acid sequences; for the less rigidly constrained hemoglobins, which interact mainly with oxygen and other small molecules; and for fibrinopeptides, which are protein fragments that are cut from larger proteins (fibrinogens) when blood clots. The clock for fibrinopeptides runs rapidly; 1 percent of the amino acids change in a little longer than 1 million years. At the other extreme, the molecular clock runs slowly for cytochrome c; a 1 percent change in amino acid sequence requires 20 million years. The hemoglobin clock is intermediate. The concept of a molecular clock is useful for two purposes. It determines evolutionary relationships among organisms, and it indicates the time in the past when species started to diverge from one another. Once the clock for a particular gene or protein has been calibrated by reference to some event whose time is known, the actual chronological time when all other events occurred can be determined by examining the protein or gene tree. An interesting additional line of evidence supporting evolution involves sequences of DNA known as "pseudogenes." Pseudogenes are remnants of genes that no longer function but continue to be carried along in DNA as excess baggage. Pseudogenes also change through time, as they are passed on from ancestors to descendants, and they offer an especially useful way of reconstructing evolutionary relationships. With functioning genes, one possible explanation for the relative similarity between genes from different organisms is that their ways of life are similar--for example, the genes from a horse and a zebra could be more similar because of their similar habitats and behaviors than the genes from a horse and a tiger. But this possible explanation does not work for pseudogenes, since they perform no function. Rather, the degree of similarity between pseudogenes must simply reflect their evolutionary relatedness. The more remote the last common ancestor of two organisms, the more dissimilar their pseudogenes will be. The evidence for evolution from molecular biology is overwhelming and is growing quickly. In some cases, this molecular evidence makes it possible to go beyond the paleontological evidence. For example, it has long been postulated that whales descended from land mammals that had returned to the sea. From anatomical and paleontological evidence, the whales' closest living land relatives seemed to be the even-toed hoofed mammals (modern cattle, sheep, camels, goats, etc.). Recent comparisons of some milk protein genes (beta-casein and kappa-casein) have confirmed this relationship and have suggested that the closest land-bound living relative of whales may be the hippopotamus. In this case, molecular biology has augmented the fossil record. Creationism and the Evidence for Evolution Some creationists cite what they say is an incomplete fossil record as evidence for the failure of evolutionary theory. The fossil record was incomplete in Darwin's time, but many of the important gaps that existed then have been filled by subsequent paleontological research. Perhaps the most persuasive fossil evidence for evolution is the consistency of the sequence of fossils from early to recent. Nowhere on Earth do we find, for example, mammals in Devonian (the age of fishes) strata, or human fossils coexisting with dinosaur remains. Undisturbed strata with simple unicellular organisms predate those with multicellular organisms, and invertebrates precede vertebrates; nowhere has this sequence been found inverted. Fossils from adjacent strata are more similar than fossils from temporally distant strata. The most reasonable scientific conclusion that can be drawn from the fossil record is that descent with modification has taken place as stated in evolutionary theory. Special creationists argue that "no one has seen evolution occur." This misses the point about how science tests hypotheses. We don't see Earth going around the sun or the atoms that make up matter. We "see" their consequences. Scientists infer that atoms exist and Earth revolves because they have tested predictions derived from these concepts by extensive observation and experimentation. Furthermore, on a minor scale, we "experience" evolution occurring every day. The annual changes in influenza viruses and the emergence of antibiotic-resistant bacteria are both products of evolutionary forces. Indeed, the rapidity with which organisms with short generation times, such as bacteria and viruses, can evolve under the influence of their environments is of great medical significance. Many laboratory experiments have shown that, because of mutation and natural selection, such microorganisms can change in specific ways from those of immediately preceding generations. On a larger scale, the evolution of mosquitoes resistant to insecticides is another example of the tenacity and adaptability of organisms under environmental stress. Similarly, malaria parasites have become resistant to the drugs that were used extensively to combat them for many years. As a consequence, malaria is on the increase, with more than 300 million clinical cases of malaria occurring every year. Molecular evolutionary data counter a recent proposition called "intelligent design theory." Proponents of this idea argue that structural complexity is proof of the direct hand of God in specially creating organisms as they are today. These arguments echo those of the 18th century cleric William Paley who held that the vertebrate eye, because of its intricate organization, had been specially designed in its present form by an omnipotent Creator. Modern-day intelligent design proponents argue that molecular structures such as DNA, or molecular processes such as the many steps that blood goes through when it clots, are so irreducibly complex that they can function only if all the components are operative at once. Thus, proponents of intelligent design say that these structures and processes could not have evolved in the stepwise mode characteristic of natural selection. However, structures and processes that are claimed to be "irreducibly" complex typically are not on closer inspection. For example, it is incorrect to assume that a complex structure or biochemical process can function only if all its components are present and functioning as we see them today. Complex biochemical systems can be built up from simpler systems through natural selection. Thus, the "history" of a protein can be traced through simpler organisms. Jawless fish have a simpler hemoglobin than do jawed fish, which in turn have a simpler hemoglobin than mammals. The evolution of complex molecular systems can occur in several ways. Natural selection can bring together parts of a system for one function at one time and then, at a later time, recombine those parts with other systems of components to produce a system that has a different function. Genes can be duplicated, altered, and then amplified through natural selection. The complex biochemical cascade resulting in blood clotting has been explained in this fashion. Similarly, evolutionary mechanisms are capable of explaining the origin of highly complex anatomical structures. For example, eyes may have evolved independently many times during the history of life on Earth. The steps proceed from a simple eye spot made up of light-sensitive retinula cells (as is now found in the flatworm), to formation of individual photosensitive units (ommatidia) in insects with light focusing lenses, to the eventual formation of an eye with a single lens focusing images onto a retina. In humans and other vertebrates, the retina consists not only of photoreceptor cells but also of several types of neurons that begin to analyze the visual image. Through such gradual steps, very different kinds of eyes have evolved, from simple light-sensing organs to highly complex systems for vision. Human Evolution Studies in evolutionary biology have led to the conclusion that human beings arose from ancestral primates. This association was hotly debated among scientists in Darwin's day. But today there is no significant scientific doubt about the close evolutionary relationships among all primates, including humans. Many of the most important advances in paleontology over the past century relate to the evolutionary history of humans. Not one but many connecting links--intermediate between and along various branches of the human family tree--have been found as fossils. These linking fossils occur in geological deposits of intermediate age. They document the time and rate at which primate and human evolution occurred. Scientists have unearthed thousands of fossil specimens representing members of the human family. A great number of these cannot be assigned to the modern human species, Homo sapiens. Most of these specimens have been well dated, often by means of radiometric techniques. They reveal a well-branched tree, parts of which trace a general evolutionary sequence leading from ape-like forms to modern humans. Paleontologists have discovered numerous species of extinct apes in rock strata that are older than four million years, but never a member of the human family at that great age. Australopithecus, whose earliest known fossils are about four million years old, is a genus with some features closer to apes and some closer to modern humans. In brain size, Australopithecus was barely more advanced than apes. A number of features, including long arms, short legs, intermediate toe structure, and features of the upper limb, indicate that the members of this species spent part of the time in trees. But they also walked upright on the ground, like humans. Bipedal tracks of Australopithecus have been discovered, beautifully preserved with those of other extinct animals, in hardened volcanic ash. Most of our Australopithecus ancestors died out close to two-and-a-half million years ago, while other Australopithecus species, which were on side branches of the human tree, survived alongside more advanced hominids for another million years. Distinctive bones of the oldest species of the human genus, Homo, date back to rock strata about 2.4 million years old. Physical anthropologists agree that Homo evolved from one of the species of Australopithecus. By two million years ago, early members of Homo had an average brain size one-and-a-half times larger than that of Australopithecus, though still substantially smaller than that of modern humans. The shapes of the pelvic and leg bones suggest that these early Homo were not part-time climbers like Australopithecus but walked and ran on long legs, as modern humans do. Just as Australopithecus showed a complex of ape-like, human-like, and intermediate features, so was early Homo intermediate between Australopithecus and modern humans in some features, and close to modern humans in other respects. The earliest stone tools are of virtually the same age as the earliest fossils of Homo. Early Homo, with its larger brain than Australopithecus, was a maker of stone tools. The fossil record for the interval between 2.4 million years ago and the present includes the skeletal remains of several species assigned to the genus Homo. The more recent species had larger brains than the older ones. This fossil record is complete enough to show that the human genus first spread from its place of origin in Africa to Europe and Asia a little less than two million years ago. Distinctive types of stone tools are associated with various populations. More recent species with larger brains generally used more sophisticated tools than more ancient species. Molecular biology also has provided strong evidence of the close relationship between humans and apes. Analysis of many proteins and genes has shown that humans are genetically similar to chimpanzees and gorillas and less similar to orangutans and other primates. DNA has even been extracted from a well-preserved skeleton of the extinct human creature known as Neanderthal, a member of the genus Homo and often considered either as a subspecies of Homo sapiens or as a separate species. Application of the molecular clock, which makes use of known rates of genetic mutation, suggests that Neanderthal's lineage diverged from that of modern Homo sapiens less than half a million years ago, which is entirely compatible with evidence from the fossil record. Based on molecular and genetic data, evolutionists favor the hypothesis that modern Homo sapiens, individuals very much like us, evolved from more archaic humans about 100,000 to 150,000 years ago. They also believe that this transition occurred in Africa, with modern humans then dispersing to Asia, Europe, and eventually Australasia and the Americas. Discoveries of hominid remains during the past three decades in East and South Africa, the Middle East, and elsewhere have combined with advances in molecular biology to initiate a new discipline--molecular paleoanthropology. This field of inquiry is providing an ever-growing inventory of evidence for a genetic affinity between human beings and the African apes. Opinion polls show that many people believe that divine intervention actively guided the evolution of human beings. Science cannot comment on the role that supernatural forces might play in human affairs. But scientific investigations have concluded that the same forces responsible for the evolution of all other life forms on Earth can account for the evolution of human beings. Conclusion Science is not the only way of acquiring knowledge about ourselves and the world around us. Humans gain understanding in many other ways, such as through literature, the arts, philosophical reflection, and religious experience. Scientific knowledge may enrich aesthetic and moral perceptions, but these subjects extend beyond science's realm, which is to obtain a better understanding of the natural world. The claim that equity demands balanced treatment of evolutionary theory and special creation in science classrooms reflects a misunderstanding of what science is and how it is conducted. Scientific investigators seek to understand natural phenomena by observation and experimentation. Scientific interpretations of facts and the explanations that account for them therefore must be testable by observation and experimentation. Creationism, intelligent design, and other claims of supernatural intervention in the origin of life or of species are not science because they are not testable by the methods of science. These claims subordinate observed data to statements based on authority, revelation, or religious belief. Documentation offered in support of these claims is typically limited to the special publications of their advocates. These publications do not offer hypotheses subject to change in light of new data, new interpretations, or demonstration of error. This contrasts with science, where any hypothesis or theory always remains subject to the possibility of rejection or modification in the light of new knowledge. No body of beliefs that has its origin in doctrinal material rather than scientific observation, interpretation, and experimentation should be admissible as science in any science course. Incorporating the teaching of such doctrines into a science curriculum compromises the objectives of public education. Science has been greatly successful at explaining natural processes, and this has led not only to increased understanding of the universe but also to major improvements in technology and public health and welfare. The growing role that science plays in modern life requires that science, and not religion, be taught in science classes. |
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| fyi | Sep 17 2006, 12:01 PM Post #39 |
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Principal
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This sums up how I feel about the subject. I personally do not believe that "Intelligent Design" belongs in public school science classes. I think it is my responsibility, as a parent, to teach my children about religion.** Maybe the public school should offer an "Intelligent Design" elective? Parents could to chose to opt their child in or out. It would be similiar to the sex education classes they currently offer to our children. If it conflicts with your belief system, your child would not be required to participate. **On a side note, I also believe that it is my responsibiity, as a parent, to teach my child about sex education.
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| Corwin | Sep 17 2006, 03:02 PM Post #40 |
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Principal
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Thanks for agreeing with me - I am sure that was hard to do :lol: The bottom line with evolution is you have to be able to accept spontaneous generation of life. Despite bones and teeth (some misidentified), there has been no evidence to support life from nothing. Until further evidence is discovered, I don't know how that can be taught in schools as anything more than conjecture. |
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| fyi | Sep 17 2006, 05:05 PM Post #41 |
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Principal
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http://pinker.wjh.harvard.edu/articles/med...08_07_time.html Sunday, Aug. 07, 2005 [size=7]Can You Believe in God and Evolution?[/size] Four experts with very different views weigh in on the underlying question. COMPILED BY DAVID VAN BIEMA FRANCIS COLLINS Director, National Human Genome Research Institute I see no conflict in what the Bible tells me about God and what science tells me about nature. Like St. Augustine in A.D. 400, I do not find the wording of Genesis 1 and 2 to suggest a scientific textbook but a powerful and poetic description of God's intentions in creating the universe. The mechanism of creation is left unspecified. If God, who is all powerful and who is not limited by space and time, chose to use the mechanism of evolution to create you and me, who are we to say that wasn't an absolutely elegant plan? And if God has now given us the intelligence and the opportunity to discover his methods, that is something to celebrate. I lead the Human Genome Project, which has now revealed all of the 3 billion letters of our own DNA instruction book. I am also a Christian. For me scientific discovery is also an occasion of worship. Nearly all working biologists accept that the principles of variation and natural selection explain how multiple species evolved from a common ancestor over very long periods of time. I find no compelling examples that this process is insufficient to explain the rich variety of life forms present on this planet. While no one could claim yet to have ferreted out every detail of how evolution works, I do not see any significant "gaps" in the progressive development of life's complex structures that would require divine intervention. In any case, efforts to insert God into the gaps of contemporary human understanding of nature have not fared well in the past, and we should be careful not to do that now. Science's tools will never prove or disprove God's existence. For me the fundamental answers about the meaning of life come not from science but from a consideration of the origins of our uniquely human sense of right and wrong, and from the historical record of Christ's life on Earth. STEVEN PINKER Psychology professor, Harvard University It's natural to think that living things must be the handiwork of a designer. But it was also natural to think that the sun went around the earth. Overcoming naive impressions to figure out how things really work is one of humanity's highest callings. Our own bodies are riddled with quirks that no competent engineer would have planned but that disclose a history of trial-and-error tinkering: a retina installed backward, a seminal duct that hooks over the ureter like a garden hose snagged on a tree, goose bumps that uselessly try to warm us by fluffing up long-gone fur. The moral design of nature is as bungled as its engineering design. What twisted sadist would have invented a parasite that blinds millions of people or a gene that covers babies with excruciating blisters? To adapt a Yiddish expression about God: If an intelligent designer lived on Earth, people would break his windows. The theory of natural selection explains life as we find it, with all its quirks and tragedies. We can prove mathematically that it is capable of producing adaptive life forms and track it in computer simulations, lab experiments and real ecosystems. It doesn't pretend to solve one mystery (the origin of complex life) by slipping in another (the origin of a complex designer). Many people who accept evolution still feel that a belief in God is necessary to give life meaning and to justify morality. But that is exactly backward. In practice, religion has given us stonings, inquisitions and 9/11. Morality comes from a commitment to treat others as we wish to be treated, which follows from the realization that none of us is the sole occupant of the universe. Like physical evolution, it does not require a white-coated technician in the sky. MICHAEL BEHE Biochemistry professor, Lehigh University; Senior fellow, Discovery Institute Sure, it's possible to believe in both God and evolution. I'm a Roman Catholic, and Catholics have always understood that God could make life any way he wanted to. If he wanted to make it by the playing out of natural law, then who were we to object? We were taught in parochial school that Darwin's theory was the best guess at how God could have made life. I'm still not against Darwinian evolution on theological grounds. I'm against it on scientific grounds. I think God could have made life using apparently random mutation and natural selection. But my reading of the scientific evidence is that he did not do it that way, that there was a more active guiding. I think that we are all descended from some single cell in the distant past but that that cell and later parts of life were intentionally produced as the result of intelligent activity. As a Christian, I say that intelligence is very likely to be God. Several Christian positions are theologically consistent with the theory of mutation and selection. Some people believe that God is guiding the process from moment to moment. Others think he set up the universe from the Big Bang to unfold like a computer program. Others take scientific positions that are indistinguishable from those atheist materialists might take but say that their nonscientific intuitions or philosophical considerations or the existence of the mind lead them to deduce that there is a God. I used to be part of that last group. I just think now that the science is not nearly as strong as they think. ALBERT MOHLER President, Southern Baptist Theological Seminary Given the human tendency toward inconsistency, there are people who will say they hold both positions. But you cannot coherently affirm the Christian-truth claim and the dominant model of evolutionary theory at the same time. Personally, I am a young-Earth creationist. I believe the Bible is adequately clear about how God created the world, and that its most natural reading points to a six-day creation that included not just the animal and plant species but the earth itself. But there have always been Evangelicals who asserted that it might have taken longer. What they should not be asserting is the idea of God's having set the rules for evolution and then stepped back. And even less so, the model held by much of the scientific academy: of evolution as the result of a random process of mutation and selection. For one thing, there's the issue of human "descent." Evangelicals must absolutely affirm the special creation of humans in God's image, with no physical evolution from any nonhuman species. Just as important, the Bible clearly teaches that God is involved in every aspect and moment in the life of His creation and the universe. That rules out the image of a kind of divine watchmaker. I think it's interesting that many of evolution's most ardent academic defenders have moved away from the old claim that evolution is God's means to bring life into being in its various forms. More of them are saying that a truly informed belief in evolution entails a stance that the material world is all there is and that the natural must be explained in purely natural terms. They're saying that anyone who truly feels this way must exclude God from the story. I think their self-analysis is correct. I just couldn't disagree more with their premise. |
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| SJC | Sep 17 2006, 10:31 PM Post #42 |
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Principal
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What's with all the Google & pasting? Don't you trust me? My simple, short explanations of the terminology are accurate. |
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| cmic | Sep 18 2006, 05:57 AM Post #43 |
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Principal
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"Some misidentified" is nowhere near the amount that has been identified correctly. Evolution is an important part of science. I am not discrediting creationism as being important, just not appropriate for school (public). |
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| fyi | Sep 18 2006, 06:12 AM Post #44 |
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Principal
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Just confirming that you are right. I agree with you.
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| BoaterDan | Sep 18 2006, 10:48 AM Post #45 |
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Principal
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I could easily be dragged into this as a great debate topic, ... but ah, if only I had the time. I'll probably just make this one comment... First, let me make a differentiation between evolution of the type that has been observed over the course of one person's lifetime in many examples and Darwin's theories on the origins of life. Nobody in their right mind with even cursory scientific knowledge denies the first - it is only the idea that all life came from the "ooze" that is in question. It may interestest some of you to know that the Intelligent Design movement was started by a handful of scientists who did NOT have a Judeo-Christian faith in common. That is, some of them were staunchly agnostic at least. It has been adopted by many leaders of faith organizations for obvious reasons, but it is at its core decidedly not theological, and that is not just lipservice given by religious people so as to give it the appearance of credibility. The premise of ID is basically that there are details of our world, like the irreducably complex structures like the cellular flagellum, for which there is no possible explanation via evolutionary processes. The ID scientists say that we must therefore conclude some process other than evolution is responsible for them, and the obvious alternative is some kind of intelligent design. In fact, the only possible solutions really are either that we just don't know enough about evolutionary processes yet or that there's some other process. To suggest that one is a silly leap of faith and the other is scientific deduction is itself ludicrous. It may also interest you that Darwin himself said basically that if evidence is found contrary to his theory that the theory must be thrown out with the bathwater. I don't want the public school teaching religion - Not christian creationism, not buddhism, and not islam, unless in the context of some kind of "religions of the world" class. What I also object to is the teaching of origin evolution as proven scientific fact, which is the way I've seen it represented my kid's textbooks. And I'm saying this not as a crazed religious nut who's heard on some radio show about somebody somewhere who's second cousin's brother-in-law blah blah blah - I'm saying what I have personally read in my kids' textbooks is a little disturbing from a scientific point of view alone in the way that it discourages them from even considering the real science (or lack thereof) behind statements like "that's because 200,000,000 years ago..." I would like to see the public school teaching simply: that origin evolution is one possible explanation for our existence which has a lot of supporting evidence up to a point, but is also by definition unproven and completely unable to explain some of our observations. That these latter points have led some scientists to conclude there must have been some kind of intelligent force responsible for at least those phenomena. And that the most popular alternative to complete origin evolution is some variation of a theological belief that a creative being was responsible for bring our world into existence, possibly via evolutionary processes to some degree. Since that last point is not really a scientific proposition we will not really be examining or discussing it any further than this mention. |
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