Saturday, September 03, 2005

The History of Chromosomes May Shape the Future of Diseases, etc


Here are science news excerpts, with my comments in square brackets and bold for easier distinguishing between them and the articles:


The History of Chromosomes May Shape the Future of Diseases, Carl Zimmer, The New York Times, August 30, 2005. The common ancestor of humans and the rhesus macaque monkey lived about 25 million years ago. But despite that vast gulf of time, our chromosomes still retain plenty of evidence of our shared heritage. ... A team of scientists at the National Cancer Institute recently documented this evidence by constructing a map of the rhesus macaque's DNA, noting the location of 802 genetic markers in its genome. Then they compared the macaque map to a corresponding map of the human genome. The order of thousands of genes was the same. "About half of the chromosomes are pretty much intact," said William Murphy ... at Texas A&M University. The other chromosomes had become rearranged over the past 25 million years, but Dr. Murphy and his colleagues were able to reconstruct their evolution. Periodically, a chunk of chromosome was accidentally sliced out of the genome, flipped around and inserted backward. In other cases, the chunk was ferried to a different part of the chromosome. All told, 23 of these transformations took place, and within these blocks of DNA, the order of the genes remained intact. "It's fairly easy to see how you can convert the chromosomes from the macaque to the human," Dr. Murphy said. This new macaque study, which is set to appear in a future issue of the journal Genomics, is just one of many new papers charting the history of chromosomes - in humans and other species. ... With a microscope, it is possible to make out the banded patterns on chromosomes and to compare the pattern in different species. ... molecular biologists discovered how cells accidentally rearranged large chunks of genetic material as they made new copies of their chromosomes. ... Humans have 23 pairs of chromosomes, for example, while chimpanzees and other apes have 24. Scientists determined that two ancestral chromosomes fused together after the ancestors of humans split off from other apes some six million years ago. ... Deciphering the history of chromosomes is like a fiendishly difficult puzzle. ... Pavel Pevzner of the University of California, San Diego... invented a fast method for comparing chromosomes from two different species and determining the fewest number of rearrangements ... that separate them. ... Scientists have used methods like Dr. Pevzner's to study different groups of species. Dr. Pevzner himself joined with Dr. Murphy and 23 other scientists to analyze the last 100 million years of mammal evolution. They compared the genomes of humans to cats, dogs, mice, rats, pigs, cows and horses, using a program developed by Harris A. Lewin and his colleagues at the University of Illinois, called the Evolution Highway. The program allowed them to trace how each lineage's chromosomes had become rearranged over time. They published their results in the July 22 issue of Science. The scientists found some chromosomes barely altered and others heavily reworked. ... Chromosome rearrangements may also play a role in the origin of new species. Scientists often find that closely related species living in overlapping ranges have rearranged chromosomes. The mismatch of chromosomes may make it impossible for the two species to hybridize. As a result, the rearrangements may then spread through the entire new species. ... chromosomes tend to break in certain places, a hypothesis first offered by Dr. Pevzner in 2003. ... "Certain regions of the genome are being broken over and over again." It is too early to say why these regions have become break points, said Evan Eichler of the University of Washington .... "There's something about these regions that makes them hot, and we have to figure out what that hot factor is," ... [This is more evidence for humans, apes and monkeys sharing a common ancestor, that the chromosome bands either match exactly already, or when inversions are reversed and translocations rejoined, they match exactly. One of the things that helped confirm to me that common ancestry was true, was the article, Yunis J.J. & & Prakash O., "The Origin of Man: A Chromosomal Pictorial Legacy," Science, Vol. 215, No. 4539, March 1982, pp.1525-1530, p.1525, with chromosome maps of an orangutan, gorilla, chimpanzee, and man side-by-side. I remember in one of my Genetics assignments (even though it was not required), enlarging on a photocopy the chimp and human chromosome maps, and then with scissors and glue proving to myself that where their bandings differed, just reversing or joining them, I could produce a near-identical fit. Here is the abstract of that article:


"Abstract. Man, gorilla, and chimpanzee likely shared an ancestor in whom the fine genetic organization of chromosomes was similar to that of present man. A comparative analysis of high-resolution chromosomes from orangutan, gorilla, chimpanzee, and man suggests that 18 of 23 pairs of chromosomes of modern man are virtually identical to those of our "common hominoid ancestor," with the remaining pairs slightly different. From this lineage, gorilla separated first, and three major chromosomal rearrangements presumably occurred in a progenitor of chimpanzee and man before the final divergence of these two species. A precursor of the hominoid ancestor and orangutan is also assumed." (Yunis J.J. & & Prakash O., "The Origin of Man: A Chromosomal Pictorial Legacy," Science, Vol. 215, No. 4539, March 1982, pp.1525-1530, p.1525)


I have added a modified version of these comments to my,  "Why I (a Creationist) Accept Common Ancestry" page.]


Boost to CO2 mass extinction idea, Helen Briggs, BBC, 28 August 2005. A computer simulation of the Earth's climate 250 million years ago suggests that global warming triggered the so-called "great  dying". A dramatic rise in carbon dioxide caused temperatures to soar to 10 to 30 degrees Celsius higher than today, say US  researchers. The warming had a profound impact on the oceans, cutting off oxygen to the lower depths and extinguishing most lifeforms, they  write in the latest issue of Geology. The research adds to the growing body of evidence that higher temperatures, rather than a giant space rock hitting the planet, led  to the greatest mass extinction in history. ... The extinction, at the end of the Permian Period and the beginning of the Triassic, has puzzled scientists for many years. Trilobites were one of the groups wiped out in the extinction. Some 95% of lifeforms in the oceans became extinct, along with about three-quarters of land species. Many possible reasons for this catastrophic event have been proposed - including impacts, volcanism, climate change and  glaciation. Hard evidence, however, has been difficult to find. The latest data from scientists at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, supports the  view that extensive volcanic activity over the course of hundreds of thousands of years released large amounts of carbon dioxide  and sulphur dioxide into the air, gradually warming up the planet. ... Their work indicates that temperatures in higher latitudes rose so much that the oceans warmed to a depth of about 3,000m  (10,000ft). This interfered with the circulation process that takes colder water, carrying oxygen and nutrients, into lower levels. The water  became depleted of oxygen and was unable to support marine life. "The implication of our study is that elevated CO2 is sufficient to lead to inhospitable conditions for marine life and excessively  high temperatures over land would contribute to the demise of terrestrial life," Jeffrey Kiehl and colleagues write ... Until recently, computer models of past climate have been hampered by the difficulty of accounting for complex interactions  between the various components of the Earth's climate system Professor Paul Wignal ... says the models have not  been sophisticated enough to recreate such "lethal super-greenhouse climates". "I suspect many in the modelling community have been sceptical about just how bad conditions were 250 million years ago, even  though the evidence is in the rocks; but now the latest climate system modelling is able to replicate climatic conditions that came  close to destroying life on Earth," ... [I regard such mass extinctions, putting all of life through a `bottleneck', as all part of the Grand Design, God `pruning the tree of life', without which we would not be here. They are also another problem of evolution, i.e. `survival of the luckiest':

"Survival of the luckiest. Perhaps the most far-reaching effect of this revival of catastrophist thinking has been the dawning realization that mass extinction makes a nonsense of natural selection as a 'creative' force. David Raup of Chicago's Field Museum has calculated that in the half-dozen major extinctions, *up to ninety-six per cent of all life forms were destroyed.* [Raup D.M., "Conflicts between Darwin and Paleontology," ," Bulletin of the Field Museum of Natural History, Chicago IL, Vol. 50, January 1979] Now if only four per cent of living things managed to survive such cataclysms, the question of fitness is largely irrelevant. It is much more a question of chance. Instead of survival of the fittest, you get the survival of the luckiest. The worst catastrophe, everyone agrees, was at the end of the Permian period some 225 million years ago. It established the ancestry of most of today's life forms, for since then there has been little change in the basic pattern of types. But as Stephen Gould has observed, it wasn't necessarily the best-adapted Permian plants and creatures that lived through the disaster: `If anywhere near 96 per cent of species died, leaving as few as two thousand forms to propagate all of later life, then some groups probably died and others survived for no particular reason at all. There are few defences against a catastrophe of such magnitude, and survivors may simply be among the lucky four per cent...our current panoply of major designs may not represent a set of best adaptations, but fortunate survivors.' [Gould S.J., 'The chance that shapes our ends', New Scientist, 5 February 1981, p. 349]" (Hitching F., "The Neck of the Giraffe: Or Where Darwin Went Wrong," Pan: London UK, 1982, pp.166,170. Emphasis original)

This also shows that a runaway, positive-feedback, mass-extinguishing greenhouse global warming effect is possible, and I personally think it may be what will become increasingly apparent is going to happen on Earth, forcing the world's governments to increasingly hand over power to a "World Environment Organisation":

"International action to cut greenhouse gases is on the way, a leading British expert on the environment believes. Sir Crispin Tickell, a former diplomat and government adviser, says urgent action is needed because climate change is more serious even than terrorism. ... In a speech in Cambridge Sir Crispin says he thinks the world will finally act together to confront the threat. ... Speaking in the first of a series of lectures entitled Environment on the Edge, he says the Earth is in an unparalleled situation, because several problems are reaching a critical point simultaneously. The lectures are organised by the United Nations Environment Programme ... Our problems are taking us into `a no-analogue state', Sir Crispin says, and our ability to influence other species `has given us a profound conceit of ourselves'. The six main threats he believes are pushing the environment to the edge are: population increase; land degradation and waste; water pollution and supply; climate change; energy production and use; and the destruction of biodiversity. ... Sir Crispin argues for the creation of a World Environment Organisation `to balance - and be a partner of - the World Trade Organisation'. ... To bring about change, he says, `we need three things: leadership from above; public pressure from below; and - usually - some instructive disasters to jerk us out of our inertia." ("World 'will act on climate gases'," BBC, 4 November, 2004.)


out of which Antichrist will emerge (1 John 2:18, 22; 4:3; 2 John 1:7; 2 Thess. 2:1-4; Rev 11:1-8; 13:2-18) who will launch the last great persecution of the Christian Church, just before Jesus returns. ] 


Scientific Savvy? In U.S., Not Much, Cornelia Dean, The New York Times, August 30, 2005 CHICAGO - When Jon D. Miller looks out across America, which he can almost do from his 18th-floor office at Northwestern University Medical School in Chicago, he sees a landscape of haves and have-nots - in terms not of money, but of knowledge. ... scientific illiteracy undermines citizens' ability to take part in the democratic process. Dr. Miller, 63, a political scientist who directs the Center for Biomedical Communications at the medical school, studies how much Americans know about science and what they think about it. His findings are not encouraging. While scientific literacy has doubled over the past two decades, only 20 to 25 percent of Americans are "scientifically savvy and alert," he said in an interview. Most of the rest "don't have a clue." At a time when science permeates debates on everything from global warming to stem cell research, he said, people's inability to understand basic scientific concepts undermines their ability to take part in the democratic process. Over the last three decades, Dr. Miller has regularly surveyed his fellow citizens .... People who track Americans' attitudes toward science routinely cite his deep knowledge and long track record. "I think we should pay attention to him," said Eugenie Scott, director of the National Center for Science Education, who cites Dr. Miller's work in her efforts to advance the cause of evolution in the classroom. "We ignore public understanding of science at our peril." ... Lately, people who advocate the teaching of evolution have been citing Dr. Miller's ideas on what factors are correlated with adherence to creationism and rejection of Darwinian theories. In general, he says, these fundamentalist views are most common among people who are not well educated and who "work in jobs that are evaporating fast with competition around the world." But not everyone is happy when he says things like that. Every time he goes on the radio to talk about his findings, he said, "I get people sending me cards saying they will pray for me a lot." ... [The scientific materialist elite never consider that their atheistic declaration of culture war against the vast majority of Americans who are theists, is almost certainly a major factor in the American public's increasingly negative and indifferent attitude toward science!]


Stephen E. Jones, BSc (Biol)

"Problems of Evolution"


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