So what you have garnered from your plethora of left leaning sources is that 49% of Republicans basically don't believe in evolution without some sort of Supreme Being involved. There is no doubt that evolution occurred. There is also no doubt that the odds of it happening by chance are about the same as a tornado passing through a junkyard and completely by chance building a 747 down to the last screw in the pilot's coffee pot. That's just one-celled organisms. Evolution teaches that one-celled pre-Cambrian organisms, in a Geological eyeblink, somehow more exploded than evolved into the vast myriad of complex Cambrian life forms. There is a lot of evidence of the Cambrian period's life. There is no transitional evidence of how it came to be. Then there were the remarkable recoveries during the Ordovician and especially the Permian die offs. How amphibians became reptiles is far more complicated than how ape-like creatures became homo sapiens. (Those that actually made the transition, that is.)
There is less of a disbelief in evolutionary theory than the recognition that it IS a theory. Not in the fact that it happened, but in the HOW it happened. Much of what is taught as evolutionary "fact" is nothing more than speculation wrapped in a mantle of "authority."
We have millions of fossils of assorted life forms, both flora and fauna, but pretty much nothing in the way of transitional fossils that show how form "A" became form "B". There is just about as much proof of a God waving a magic wand as there is of a gradual evolution. I think many evolutionists are more interested in the promotion of Atheism rather than actual science. Especially the foundation of all science, which is mathematics. That foundation's probability theory states that evolution by complete chance is so unlikely it is beyond impossible, yet we are asked to believe that it happened not once, but countless quadrillions of times.
There are those who speculate the primal mass from which the Big Bang occurred was somehow left over from some sort of previous universe, and find this unfounded and unproven speculation believable, yet scoff at the idea of a Supreme Being as a fairy tale.
Children are taught from an "artists' conception" that a certain dinosaur had a certain physical appearance. This is taught as fact when the fact it that no one KNOWS what it actually looked like. It is guesswork based on extrapolation from some of the more complete skeletons that actually have been unearthed, and actually did exist.
The actual nuts and bolts mechanics of how evolution actually occurred enjoy representation as fact when a lot of it is guesswork. We know it happened, but in so many cases, not HOW. My own problem lies in the presentation of speculation as fact.
Your post leaves the impression that Republican politicians are superstitious imbeciles; yet the actions of the scientific community in joining in lockstep to present guesswork and wishful thinking as fact seems to leave you unfazed.
This is the same scientific community who joined with the religion they now despise to castigate Copernicus, Galileo, Demosthenes, and William Harvey as being heretic. Looks like the pendulum has swung back the other way.
No offense, but your one-sided drive-by deserved a response.
Peace, Love and Blue Tofu.

So what you have garnered from your plethora of left leaning sources is that 49% of Republicans basically don't believe in evolution without some sort of Supreme Being involved. There is no doubt that evolution occurred. There is also no doubt that the odds of it happening by chance are about the same as a tornado passing through a junkyard and completely by chance building a 747 down to the last screw in the pilot's coffee pot. That's just one-celled organisms. Evolution teaches that one-celled pre-Cambrian organisms, in a Geological eyeblink, somehow more exploded than evolved into the vast myriad of complex Cambrian life forms. There is a lot of evidence of the Cambrian period's life. There is no transitional evidence of how it came to be. Then there were the remarkable recoveries during the Ordovician and especially the Permian die offs. How amphibians became reptiles is far more complicated than how ape-like creatures became homo sapiens. (Those that actually made the transition, that is.)
There is less of a disbelief in evolutionary theory than the recognition that it IS a theory. Not in the fact that it happened, but in the HOW it happened. Much of what is taught as evolutionary "fact" is nothing more than speculation wrapped in a mantle of "authority."
We have millions of fossils of assorted life forms, both flora and fauna, but pretty much nothing in the way of transitional fossils that show how form "A" became form "B". There is just about as much proof of a God waving a magic wand as there is of a gradual evolution. I think many evolutionists are more interested in the promotion of Atheism rather than actual science. Especially the foundation of all science, which is mathematics. That foundation's probability theory states that evolution by complete chance is so unlikely it is beyond impossible, yet we are asked to believe that it happened not once, but countless quadrillions of times.
There are those who speculate the primal mass from which the Big Bang occurred was somehow left over from some sort of previous universe, and find this unfounded and unproven speculation believable, yet scoff at the idea of a Supreme Being as a fairy tale.
Children are taught from an "artists' conception" that a certain dinosaur had a certain physical appearance. This is taught as fact when the fact it that no one KNOWS what it actually looked like. It is guesswork based on extrapolation from some of the more complete skeletons that actually have been unearthed, and actually did exist.
The actual nuts and bolts mechanics of how evolution actually occurred enjoy representation as fact when a lot of it is guesswork. We know it happened, but in so many cases, not HOW. My own problem lies in the presentation of speculation as fact.
Your post leaves the impression that Republican politicians are superstitious imbeciles; yet the actions of the scientific community in joining in lockstep to present guesswork and wishful thinking as fact seems to leave you unfazed.
This is the same scientific community who joined with the religion they now despise to castigate Copernicus, Galileo, Demosthenes, and William Harvey as being heretic. Looks like the pendulum has swung back the other way.
No offense, but your one-sided drive-by deserved a response.
Peace, Love and Blue Tofu.

So what you have garnered from your plethora of left leaning sources is that 49% of Republicans basically don't believe in evolution without some sort of Supreme Being involved. There is no doubt that evolution occurred. There is also no doubt that the odds of it happening by chance are about the same as a tornado passing through a junkyard and completely by chance building a 747 down to the last screw in the pilot's coffee pot. That's just one-celled organisms. Evolution teaches that one-celled pre-Cambrian organisms, in a Geological eyeblink, somehow more exploded than evolved into the vast myriad of complex Cambrian life forms. There is a lot of evidence of the Cambrian period's life. There is no transitional evidence of how it came to be. Then there were the remarkable recoveries during the Ordovician and especially the Permian die offs. How amphibians became reptiles is far more complicated than how ape-like creatures became homo sapiens. (Those that actually made the transition, that is.)
There is less of a disbelief in evolutionary theory than the recognition that it IS a theory. Not in the fact that it happened, but in the HOW it happened. Much of what is taught as evolutionary "fact" is nothing more than speculation wrapped in a mantle of "authority."
We have millions of fossils of assorted life forms, both flora and fauna, but pretty much nothing in the way of transitional fossils that show how form "A" became form "B". There is just about as much proof of a God waving a magic wand as there is of a gradual evolution. I think many evolutionists are more interested in the promotion of Atheism rather than actual science. Especially the foundation of all science, which is mathematics. That foundation's probability theory states that evolution by complete chance is so unlikely it is beyond impossible, yet we are asked to believe that it happened not once, but countless quadrillions of times.
There are those who speculate the primal mass from which the Big Bang occurred was somehow left over from some sort of previous universe, and find this unfounded and unproven speculation believable, yet scoff at the idea of a Supreme Being as a fairy tale.
Children are taught from an "artists' conception" that a certain dinosaur had a certain physical appearance. This is taught as fact when the fact it that no one KNOWS what it actually looked like. It is guesswork based on extrapolation from some of the more complete skeletons that actually have been unearthed, and actually did exist.
The actual nuts and bolts mechanics of how evolution actually occurred enjoy representation as fact when a lot of it is guesswork. We know it happened, but in so many cases, not HOW. My own problem lies in the presentation of speculation as fact.
Your post leaves the impression that Republican politicians are superstitious imbeciles; yet the actions of the scientific community in joining in lockstep to present guesswork and wishful thinking as fact seems to leave you unfazed.
This is the same scientific community who joined with the religion they now despise to castigate Copernicus, Galileo, Demosthenes, and William Harvey as being heretic. Looks like the pendulum has swung back the other way.
No offense, but your one-sided drive-by deserved a response.
Peace, Love and Blue Tofu.

Transitional Fossils: http://www.talkorigins.org/indexcc/CC/CC200.html


There are many transitional fossils. The only way that the claim of their absence may be remotely justified, aside from ignoring the evidence completely, is to redefine "transitional" as referring to a fossil that is a direct ancestor of one organism and a direct descendant of another. However, direct lineages are not required; they could not be verified even if found. What a transitional fossil is, in keeping with what the theory of evolution predicts, is a fossil that shows a mosaic of features from an older and more recent organism.

Transitional fossils may coexist with gaps. We do not expect to find finely detailed sequences of fossils lasting for millions of years. Nevertheless, we do find several fine gradations of fossils between species and genera, and we find many other sequences between higher taxa that are still very well filled out.

The following are fossil transitions between species and genera:

Human ancestry. There are many fossils of human ancestors, and the differences between species are so gradual that it is not always clear where to draw the lines between them.

The horns of titanotheres (extinct Cenozoic mammals) appear in progressively larger sizes, from nothing to prominence. Other head and neck features also evolved. These features are adaptations for head-on ramming analogous to sheep behavior (Stanley 1974).

A gradual transitional fossil sequence connects the foraminifera Globigerinoides trilobus and Orbulina universa (Pearson et al. 1997). O. universa, the later fossil, features a spherical test surrounding a "Globigerinoides-like" shell, showing that a feature was added, not lost. The evidence is seen in all major tropical ocean basins. Several intermediate morphospecies connect the two species, as may be seen in the figure included in Lindsay (1997).

The fossil record shows transitions between species of Phacops (a trilobite; Phacops rana is the Pennsylvania state fossil; Eldredge 1972; 1974; Strapple 1978).

Planktonic forminifera (Malmgren et al. 1984). This is an example of punctuated gradualism. A ten-million-year foraminifera fossil record shows long periods of stasis and other periods of relatively rapid but still gradual morphologic change.

Fossils of the diatom Rhizosolenia are very common (they are mined as diatomaceous earth), and they show a continuous record of almost two million years which includes a record of a speciation event (Miller 1999, 44-45).

Lake Turkana mollusc species (Lewin 1981).

Cenozoic marine ostracodes (Cronin 1985).

The Eocene primate genus Cantius (Gingerich 1976, 1980, 1983).

Scallops of the genus Chesapecten show gradual change in one "ear" of their hinge over about 13 million years. The ribs also change (Pojeta and Springer 2001; Ward and Blackwelder 1975).

Gryphaea (coiled oysters) become larger and broader but thinner and flatter during the Early Jurassic (Hallam 1968).

The following are fossil transitionals between families, orders, and classes:

Human ancestry. Australopithecus, though its leg and pelvis bones show it walked upright, had a bony ridge on the forearm, probably vestigial, indicative of knuckle walking (Richmond and Strait 2000).

Dinosaur-bird transitions.

Haasiophis terrasanctus is a primitive marine snake with well-developed hind limbs. Although other limbless snakes might be more ancestral, this fossil shows a relationship of snakes with limbed ancestors (Tchernov et al. 2000). Pachyrhachis is another snake with legs that is related to Haasiophis (Caldwell and Lee 1997).

The jaws of mososaurs are also intermediate between snakes and lizards. Like the snake's stretchable jaws, they have highly flexible lower jaws, but unlike snakes, they do not have highly flexible upper jaws. Some other skull features of mososaurs are intermediate between snakes and primitive lizards (Caldwell and Lee 1997; Lee et al. 1999; Tchernov et al. 2000).

Transitions between mesonychids and whales.

Transitions between fish and tetrapods.

Transitions from condylarths (a kind of land mammal) to fully aquatic modern manatees. In particular, Pezosiren portelli is clearly a sirenian, but its hind limbs and pelvis are unreduced (Domning 2001a, 2001b).

Runcaria, a Middle Devonian plant, was a precursor to seed plants. It had all the qualities of seeds except a solid seed coat and a system to guide pollen to the seed (Gerrienne et al. 2004).

A bee, Melittosphex burmensis, from Early Cretaceous amber, has primitive characteristics expected from a transition between crabronid wasps and extant bees (Poinar and Danforth 2006).

The following are fossil transitionals between kingdoms and phyla:

The Cambrian fossils Halkiera and Wiwaxia have features that connect them with each other and with the modern phyla of Mollusca, Brachiopoda, and Annelida. In particular, one species of halkieriid has brachiopod-like shells on the dorsal side at each end. This is seen also in an immature stage of the living brachiopod species Neocrania. It has setae identical in structure to polychaetes, a group of annelids. Wiwaxia and Halkiera have the same basic arrangement of hollow sclerites, an arrangement that is similar to the chaetae arrangement of polychaetes. The undersurface of Wiwaxia has a soft sole like a mollusk's foot, and its jaw looks like a mollusk's mouth. Aplacophorans, which are a group of primitive mollusks, have a soft body covered with spicules similar to the sclerites of Wiwaxia (Conway Morris 1998, 185-195).

Cambrian and Precambrain fossils Anomalocaris and Opabinia are transitional between arthropods and lobopods.

An ancestral echinoderm has been found that is intermediate between modern echinoderms and other deuterostomes (Shu et al. 2004).

Links:
Hunt, Kathleen. 1994-1997. Transitional vertebrate fossils FAQ. http://www.talkorigins.org/faqs/faq-transitional.html

Miller, Keith B. n.d. Taxonomy, transitional forms, and the fossil record. http://www.asa3.org/ASA/resources/Miller.html

Patterson, Bob. 2002. Transitional fossil species and modes of speciation. http://www.origins.tv/darwin/transitionals.htm

Thompson, Tim. 1999. On creation science and transitional fossils. http://www.tim-thompson.com/trans-fossils.html

References:


Caldwell, M. W. and M. S. Y. Lee, 1997. A snake with legs from the marine Cretaceous of the Middle East. Nature 386: 705-709.
Conway Morris, Simon, 1998. The Crucible of Creation, Oxford University Press.
Cronin, T. M., 1985. Speciation and stasis in marine ostracoda: climatic modulation of evolution. Science 227: 60-63.
Domning, Daryl P., 2001a. The earliest known fully quadupedal sirenian. Nature 413: 625-627.
Domning, Daryl P., 2001b. New "intermediate form" ties seacows firmly to land. Reports of the National Center for Science Education 21(5-6): 38-42.
Eldredge, Niles, 1972. Systematics and evolution of Phacops rana (Green, 1832) and Phacops iowensis Delo, 1935 (Trilobita) from the Middle Devonian of North America. Bulletin of the American Museum of Natural History 147(2): 45-114.
Eldredge, Niles, 1974. Stability, diversity, and speciation in Paleozoic epeiric seas. Journal of Paleontology 48(3): 540-548.
Gerrienne, P. et al. 2004. Runcaria, a Middle Devonian seed plant precursor. Science 306: 856-858.
Gingerich, P. D., 1976. Paleontology and phylogeny: Patterns of evolution of the species level in early Tertiary mammals. American Journal of Science 276(1): 1-28.
Gingerich, P. D., 1980. Evolutionary patterns in early Cenozoic mammals. Annual Review of Earth and Planetary Sciences 8: 407-424.
Gingerich, P. D., 1983. Evidence for evolution from the vertebrate fossil record. Journal of Geological Education 31: 140-144.
Hallam, A., 1968. Morphology, palaeoecology and evolution of the genus Gryphaea in the British Lias. Philosophical Transactions of the Royal Society of London B 254: 91-128.
Lee, Michael S. Y., Gorden L. Bell Jr. and Michael W. Caldwell, 1999. The origin of snake feeding. Nature 400: 655-659.
Lewin, R., 1981. No gap here in the fossil record. Science 214: 645-646.
Lindsay, Don, 1997. A smooth fossil transition: Orbulina, a foram. http://www.don-lindsay-archive.org/creation/orbulina.html
Malmgren, B. A., W. A. Berggren and G. P. Lohmann, 1984. Species formation through punctuated gradualism in planktonic foraminifera. Science 225: 317-319.
Miller, Kenneth R., 1999. Finding Darwin's God. New York: HarperCollins.
Pearson, P. N., N. J. Shackleton and M. A. Hall. 1997. Stable isotopic evidence for the sympatric divergence of Globigerinoides trilobus and Orbulina universa (planktonic foraminifera). Journal of the Geological Society, London 154: 295-302.
Poinar, G. O. Jr. and B. N. Danforth. 2006. A fossil bee from Early Cretaceous Burmese amber. Science 314: 614.
Richmond B. G. and D. S. Strait, 2000. Evidence that humans evolved from a knuckle-walking ancestor. Nature 404: 382-385. See also Collard, M. and L. C. Aiello, 2000. From forelimbs to two legs. Nature 404: 339-340.
Shu, D.-G. et al., 2004. Ancestral echinoderms from the Chengjiang deposits of China. Nature 430: 422-428.
Stanley, Steven M., 1974. Relative growth of the titanothere horn: A new approach to an old problem. Evolution 28: 447-457.
Strapple, R. R., 1978. Tracing three trilobites. Earth Science 31(4): 149-152.
Tchernov, E. et al., 2000. A fossil snake with limbs. Science 287: 2010-2012. See also Greene, H. W. and D. Cundall, 2000. Limbless tetrapods and snakes with legs. Science 287: 1939-1941.
Ward, L. W. and B. W. Blackwelder, 1975. Chesapecten, A new genus of Pectinidae (Mollusca: Bivalvia) from the Miocene and Pliocene of eastern North America. U.S. Geological Survey Professional Paper 861.

Further Reading:
Cohn, Martin J. and Cheryll Tickle. 1999. Developmental basis of limblessness and axial patterning in snakes. Nature 399: 474-479. (technical)

Cuffey, Clifford A. 2001. The fossil record: Evolution or "scientific creation". http://www.gcssepm.org/special/cuffey_00.htm or http://www.nogs.org/cuffeyart.html

Elsberry, Wesley R. 1995. Transitional fossil challenge. http://www.rtis.com/nat/user/elsberry/evobio/evc/argresp/tranform.html

Godfrey, L. R. 1983. Creationism and gaps in the fossil record. In: Godfrey, L. R. (ed.), Scientists Confront Creationism, New York: W. W. Norton, pp. 193-218.

Morton, Glenn R. 2000. Phylum level evolution. http://home.entouch.net/dmd/cambevol.htm

Pojeta, John Jr. and Dale A. Springer. 2001. Evolution and the Fossil Record, Alexandria, VA: American Geological Institute, http://www.agiweb.org/news/spot_06apr01_evolutionbk.htm , http://www.agiweb.org/news/evolution.pdf , pg. 2.

Strahler, Arthur N. 1987. Science and Earth History, Buffalo, NY: Prometheus Books, pp. 398-400.

Zimmer, Carl. 2000. In search of vertebrate origins: Beyond brain and bone. Science 287: 1576-1579.

"Especially the foundation of all science, which is mathematics. That foundation's probability theory states that evolution by complete chance is so unlikely it is beyond impossible, yet we are asked to believe that it happened not once, but countless quadrillions of times."

Copy and paste from http://www.science20.com/stars_planets_life/calculating_odds_life_could_begin_chance

Many people, perhaps most, hate the idea that life might depend on chance processes. It is a human tendency to search for meaning, and what could be more meaningful than the belief that our lives have a greater purpose, that all life in fact is guided by a supreme intelligence which manifests itself even at the level of individual molecules?

Proponents of intelligent design believe that the components of life are so complex that they could not possibly have been produced by an evolutionary process. To bolster their argument, they calculate the odds that a specific protein might assemble by chance in the prebiotic environment. The odds against such a chance assembly are so astronomically immense that a protein required for life to begin could not possibly have assembled by chance on the early Earth. Therefore, the argument goes, life must have been designed.

It is not my purpose to argue against this belief, but the intelligent design argument uses a statistical tool of science -- a probability calculation -- to make a point, so I will use another tool of science, which is to propose an alternative hypothesis and test it. In living cells, most catalysts are protein enzymes, composed of amino acids, but in the 1980s another kind of catalyst was discovered. These are RNA molecules composed of nucleotides that are now called ribozymes. Because a ribozyme can act both as a catalyst and as a carrier of genetic information in its nucleotide sequence, it has been proposed that life passed through an RNA World phase that did not require DNA and proteins.

For the purposes of today’s column I will go through the probability calculation that a specific ribozyme might assemble by chance. Assume that the ribozyme is 300 nucleotides long, and that at each position there could be any of four nucleotides present. The chances of that ribozyme assembling are then 4^300, a number so large that it could not possibly happen by chance even once in 13 billion years, the age of the universe.

But life DID begin! Could we be missing something?

The answer, of course, is yes, we are. The calculation assumes that a single specific ribozyme must be synthesized for life to begin, but that’s not how it works. Instead, let’s make the plausible assumption that an enormous number of random polymers are synthesized, which are then subject to selection and evolution. This is the alternative hypothesis, and we can test it.

Now I will recall a classic experiment by David Bartel and Jack Szostak, published in Science in 1993. Their goal was to see if a completely random system of molecules could undergo selection in such a way that defined species of molecules emerged with specific properties. They began by synthesizing many trillions of different RNA molecules about 300 nucleotides long, but the nucleotides were all random nucleotide sequences. Nucleotides, by the way, are monomers of the nucleic acids DNA and RNA, just as amino acids are the monomers, or subunits, of proteins, and making random sequences is easy to do with modern methods of molecular biology.

They reasoned that buried in those trillions were a few catalytic RNA molecules called ribozymes that happened to catalyze a ligation reaction, in which one strand of RNA is linked to a second strand. The RNA strands to be ligated were attached to small beads on a column, then were exposed to the trillions of random sequences simply by flushing them through the column. This process could fish out any RNA molecules that happened to have even a weak ability to catalyze the reaction. They then amplified those molecules and put them back in for a second round, repeating the process for 10 rounds. By the way, this is the same basic logic that breeders use when they select for a property such as coat color in dogs.

The results were amazing. After only 4 rounds of selection and amplification they began to see an increase in catalytic activity, and after 10 rounds the rate was 7 million times faster than the uncatalyzed rate. It was even possible to watch the RNA evolve. Nucleic acids can be separated and visualized by a technique called gel electrophoresis. The mixture is put in at the top of a gel held between two glass plates and a voltage is applied. Small molecules travel fastest through the gel, and larger molecules move more slowly, so they are separated. In this case, RNA molecules having a specific length produce a visible band in a gel. At the start of the reaction, nothing could be seen, because all the molecules are different. But with each cycle new bands appeared. Some came to dominate the reaction, while others went extinct.

Bartel and Szostak’s results have been repeated and extended by other researchers, and they demonstrate a fundamental principle of evolution at the molecular level. At the start of the experiment, every molecule of RNA was different from all the rest because they were assembled by a chance process. There were no species, just a mixture of trillions of different molecules. But then a selective hurdle was imposed, a ligation reaction that allowed only certain molecules to survive and reproduce enzymatically.

In a few generations groups of molecules began to emerge that displayed ever-increasing catalytic function. In other words, species of molecules appeared out of this random mixture in an evolutionary process that closely reflects the natural selection that Darwin outlined for populations of higher animals. These RNA molecules were defined by the sequence of bases in their structures, which caused them to fold into specific conformations that had catalytic properties. The sequences were in essence analogous to genes, because the information they contained was passed between generations during the amplification process.

The Bartel and Szostak experiment directly refutes the argument that the odds are stacked against an origin of life by natural processes. The inescapable conclusion is that genetic information can in fact emerge from random mixtures of polymers, as long as the populations contain large numbers of polymeric molecules with variable monomer sequences, and a way to select and amplify a specific property.

I will close with a quote from Freeman Dyson, a theoretical physicist at Princeton University who also enjoys thinking about the origin of life:

“You had what I call the garbage bag model. The early cells were just little bags of some kind of cell membrane, which might have been oily or it might have been a metal oxide. And inside you had a more or less random collection of organic molecules, with the characteristic that small molecules could diffuse in through the membrane, but big molecules could not diffuse out. By converting small molecules into big molecules, you could concentrate the organic contents on the inside, so the cells would become more concentrated and the chemistry would gradually become more efficient. So these things could evolve without any kind of replication. It's a simple statistical inheritance. When a cell became so big that it got cut in half, or shaken in half, by some rainstorm or environmental disturbance, it would then produce two cells which would be its daughters, which would inherit, more or less, but only statistically, the chemical machinery inside. Evolution could work under those conditions.”

Copy and paste from https://www.livescience.com/10229-earth-owe-life-comets.html
"There are those who speculate the primal mass from which the Big Bang occurred was somehow left over from some sort of previous universe, and find this unfounded and unproven speculation believable, yet scoff at the idea of a Supreme Being as a fairy tale."

It is widely believed Earth was molten when it formed some 4.6 billion years ago and remained that way for its first 50 million to 100 million years. This heat would suggest the young planet also was dry.

How Earth May Owe Its Life to Comets
An artist's impression of a planet being sterilized by a continuous bombardment of comets and meteors.
Credit: David Hardy.

Comets have inspired both awe and alarm since antiquity, "hairy stars" resembling fiery swords that to many were omens of doom. Nowadays, scientists have found evidence that comets not only may have taken life away through cataclysmic impacts, they may have helped provide life by supplying Earth with vital molecules such as water — possibilities they hope to learn more about from the encounter with Comet Hartley 2 tomorrow (Nov. 4).

Comets as life-givers

It is widely believed Earth was molten when it formed some 4.6 billion years ago and remained that way for its first 50 million to 100 million years. This heat would suggest the young planet also was dry.

"As such, for a long time, people thought water was delivered sometime after the Earth formed and cooled down a bit," said astronomer David Jewitt at the University of California, Los Angeles. "So people looked around at what kinds of things loaded with water might hit Earth, and comets were the obvious answer." The giant chunks of ice called comets are, along with rocky asteroids, the leftovers from the formation of the solar system.

In addition, astronomers discovered that comet surfaces were apparently coated with organic compounds, suggesting comets also may have supplied other key ingredients for life. [How Did Life Arise on Earth?]

"However, this view began to change about 15 years ago," Jewitt explained.

Scientists began observing the levels of standard hydrogen atoms and of atoms of deuterium, which, like hydrogen, has one proton in its nucleus, but also has one neutron.

"The deuterium-to-hydrogen ratios have been observed in four comets now, and these are higher than that seen in Earth's oceans by a factor of two or three," Jewitt said. "The argument was that if the oceans were created by comets, these ratios should be the same, and they weren't."

Water, water everywhere

Some researchers began looking for other plausible sources of Earth's water and other life-giving molecules. Simulations of orbits of objects in the solar system suggested the asteroid belt would be a better source than the more-remote Kuiper belt, from where most short-period comets come — comets that need no more than 200 years to complete an orbit of the sun, which would place them close enough for a chance collision with Earth. [Video - Hunting Asteroids and Comets]

The asteroid belt is simply closer, just beyond the orbit of Mars, while the Kuiper belt is beyond the orbit of Neptune, some 30 to 40 times the distance that Earth is from the sun. Moreover, organic materials such as amino acids have been detected in the outer parts of the asteroid belt.

Analyses of deuterium-to-hydrogen ratios in the asteroid belt also showed a wide range of values, with some matching those found in Earth's oceans. In addition, comets were discovered in the asteroid belt in 2006.

"Now, these arguments are much more complicated than one might initially think," Jewitt cautioned. "First, is it really obvious that the water in the oceans should have retained the same deuterium-to-hydrogen ratios over time?" A number of geological processes might have altered these ratios, such as deep-sea hydrothermal vents.

Also, while short-period comets come from the Kuiper belt, long-period comets (ones that take more than 200 years to complete an orbit) come from the even more distant Oort cloud, and the deuterium-to-hydrogen ratios of those have not been measured yet. "Maybe those are more similar to the ones that formed the oceans," Jewitt said.

Another possibility is that Earth was not so dry when it formed. "It's hard for most people to see how hot rock can trap much water, but the argument there is that, overall, Earth is not all that wet," Jewitt said. "The mass of the oceans is only a few hundredths of 1 percent of Earth's total mass, which is pretty dry.

"My guess is that Earth's oceans were formed as a contribution of all three — comets, the asteroid belt, and the primordial material that went up to make the Earth," Jewitt said. "It's just a question of finding out which was the biggest source."

The point was very relevant. There is a difference between a largely intact specimen and making a wild-assed guess based on a few bones that look like they might have come from a similar animal, and constructing a fanciful representation. It is very relevant to my premise that much of evolutionary theory is supposition and speculation that are being treated as proven fact. The "transitional" examples given by Ms Strode are almost all simply mutations within a species. They do not show a gradual progression from one-celled to complex plant and invertebrate animals, invertebrate to vertebrate, amphibian to reptile, etc. They show changes in one species. There are truckloads of invertebrate fossils, and quite a few of early vertebrates. There are basically none of the gradual transition that supposedly occurred; and many of the small amount that do exist are pretty tenuous.
You spoke of the Flintstones. You find a fossil wheel, and assume it came from Fred and Wilma's car; hire an artist to do a conceptual picture of what he or she thinks the car might have looked like and call it an established and proven fact when you don't even know if the wheel came off of a car. This is how much of evolutionary theory is presented as fact.

Very good, except that most of what you describe are simply changes within a species. How did one-celled Pre-Cambrian organisms become complex multi-cellular plants and invertebrates so quickly? How did amphibians transition into reptiles? I was not speaking of how one reptile changed it's form, or a difference in deciduous trees. The supposed link between fish and marine mammals is pretty tenuous; and egg-laying mammals is not much of a bridge between reptiles and mammals. I am not saying this did not happen, just that the abc's of how it did are frequently guesswork bruited about as fact. Evolution itself is contradictory, as things left to chance tend to devolve rather than evolve. Fossils showing the changes from ape-like ancestors to mostly less ape-like lol are not the same as a record of the gradual changes from invertebrate to vertebrate, amphibian to reptile, etc. My whole point is that there is a fossil record to support the existence of this or that life form, but there is not one to support the "gradual changes" that are supposed to have happened. Occasional fossils which show intra-species mutations are not what I meant by transitional fossils.
Perhaps the guesses being represented as proven fact are true, but they should not be given the status of proven fact until they are such.