Draw? dinosaurs dating question
One of the most unrewarding things a scientist or science writer can attempt to do is rebut the arguments of creationists and fundamentalists. This is not because it's difficult to demolish the creationist point of view, scientifically speaking. It's because meeting anti-evolutionists on their own terms can make it seem, to some readers, as if there are two logical sides to the argument. Even so, the ways in which creationists fit dinosaurs into their Biblical worldview is a worthy topic of discussion. Learn more about some of the main arguments fundamentalists use to support their position, and discover the contrasting scientific view on each point.
Index fossils are fossils that can be used to date the rock in which they are found. The best examples are fossils of animals or plants that lived for a very short period of time and were found in a lot of places. Suppose a dinosaur fossil has been found in the beds of an ancient delta the mouth of a river leading to the sea.
The sediment of this area was laid down after ammonite A appeared million years ago, and before ammonite B became extinct million years ago. This narrows the date of the delta beds to the four million years between these dates.
FOSSILS: how fossils are dated
There are some radioactive elements in rock that decay by giving off energy and turning into different, more stable elements. This radioactive decay takes place at a constant rate for each radioactive element. Scientists know exactly how long it will take for half the quantity of the element to change, and this state is known as its half-life.
After another half-life has passed, the element will have decayed to a quarter of its original amount. After another half-life has passed, it will have decayed to an eighth, and so on. A good example of this is potassium-argon dating. So to determine the age of sedimentary rock layers, researchers first have to find neighboring layers of Earth that include igneous rock, such as volcanic ash. These layers are like bookends - they give a beginning and an end to the period of time when the sedimentary rock formed.
By using radiometric dating to determine the age of igneous bracketsresearchers can accurately determine the age of the sedimentary layers between them.
How Do Scientists Determine the Age of Dinosaur Bones?
Using the basic ideas of bracketing and radiometric dating, researchers have determined the age of rock layers all over the world. This information has also helped determine the age of the Earth itself. While the oldest known rocks on Earth are about 3. Based on the analysis of these samples, scientists estimate that the Earth itself is about 4.
In addition, the oldest known moon rocks are 4. Since the moon and the Earth probably formed at the same time, this supports the current idea of the Earth's age.
The short half-life is only part of the problem when dating dinosaur bones - researchers also have to find enough of the parent and daughter atoms to measure. Read on to see what it takes to date a fossil and what volcanic ash has to do with rhodeshotel.net: Tracy V. Wilson.
How to Make Elephant Toothpaste. How to Make Slime. Why Do We Experiment on Mice? When the authors inquired, they received this letter:.
They did not look at the data and they never spoke with the researchers. They did not like the test results, so they censored them. Carbon is considered to be a highly reliable dating technique. It's accuracy has been verified by using C to date artifacts whose age is known historically.
The fluctuation of the amount of C in the atmosphere over time adds a small uncertainty, but contamination by "modern carbon" such as decayed organic matter from soils poses a greater possibility for error. Thomas Seiler, a physicist from Germany, gave the presentation in Singapore. He said that his team and the laboratories they employed took special care to avoid contamination.
That included protecting the samples, avoiding cracked areas in the bones, and meticulous pre-cleaning of the samples with chemicals to remove possible contaminants. Knowing that small concentrations of collagen can attract contamination, they compared precision Accelerator Mass Spectrometry AMS tests of collagen and bioapatite hard carbonate bone mineral with conventional counting methods of large bone fragments from the same dinosaurs. These, together with many other remarkable concordances between samples from different fossils, geographic regions and stratigraphic positions make random contamination as origin of the C unlikely".
The theoretical limit for C dating isyears using AMS, but f or practical purposes it is 45, to 55, years, depending on the type of equipment. The half-life of C is years. If dinosaur bones are 65 million years old, there should not be one atom of C left in them. Clearly something is wrong with the conventional wisdom about dinosaur bones, but it has been hard to reach the public with the information. Despite being simple test results without any interpretation, they were not allowed to be presented in conference proceedings by the North American Paleontological Convention, the American Geophysical Union in an the Geological Society of America in an and by the editors of various scientific journals.
On one occasion, they were allowed to display a poster. Watch a video of what happens when you try to get members of the academic community involved. Dinosaur soft tissue. Many dinosaur bones are not petrified. Mary Schweitzer, paleobiology researcher and professor of biological sciences at North Carolina State University, surprised scientists in when she reported finding soft tissue in dinosaur bones.
She started a firestorm of controversy in and when she reported that she had sequenced proteins in dinosaur bone. Critics charged that the findings were mistaken or that what she called soft tissue was really biofilm produced by bacteria that had entered from outside the bone. Schweitzer answered the challenge by testing with antibodies.
Her report in confirmed the presence of collagen and other proteins that bacteria do not make. Science, Vol. Ina Swedish team found soft tissue and biomolecules in the bones of another creature from the time of the dinosaurs, a Mosasaur, which was a giant lizard that swam in shallow ocean waters.
Microspectroscopic Evidence of Cretaceous Bone Proteins. A remarkable find was published in the journal Nature in April "we report the discovery of a monotaxic embryonic dinosaur bone bed in Lower Jurassic [ million year old] strata near Dawa, Lufeng County, Yunnan Province, China".
The "bone bed is characterized by the presence of completely disarticulated skeletal elements at various stages of embryonic development". This made it possible to detect the preservation of organic residues, probably direct products of the decay of complex proteinswithin both the fast-growing embryonic bone tissue and the margins of the vascular spaces.
Our results clearly indicate the presence of both apatite and amide peaks within woven embryonic bone tissue, which should not be susceptible to microbial contamination or other post-mortem artefacts.
Huang, Eric M. Embryology of Early Jurassic dinosaur from China with evidence of preserved organic remains. Nature, Vol. The discovery of original organics in an ichthyosaur supposedly million years old Early Jurassic leaves no doubt about the preservation of soft tissue and biomolecules. Researchers from North Carolina State University and Sweden's Lund University reported their findings in "Our analyses recovered still-flexible remnants of the original scaleless skin, which comprises morphologically distinct epidermal and dermal layers.
These are underlain by insulating blubber that would have augmented streamlining, buoyancy and homeothermy. Additionally, we identify endogenous proteinaceous and lipid constituents, together with keratinocytes and branched melanophores that contain eumelanin pigment. Soft-tissue evidence for homeothermy and crypsis in a Jurassic ichthyosaur. Schweitzer wondered why such materials are preserved when all the models say they should be degraded.
She coauthored a paper published in proposing that there is a role for iron in preserving proteins in fossil tissues. However, iron is not always present in dinosaur soft tissue.
Jasmina Wiemann coauthored a paper published in proposing a different solution to the problem: polymerization of proteins in oxidative settings. A report in Science magazine explained more about these findings, showing that although the protein structure in selected dinosaur bones was changed, their organic material is apparently original.
Yet the associated brown and black bones and residues constitute only a portion of the preserved organics in dinosaur bones, as described by Brian Thomas. For years, until their access was blocked, the Paleochronology group had AMS laboratories conduct Carbon tests on dinosaur bones. The tests yielded dates in the range of 22, to 39, years before present.
Dinosaur DNA fragments. From the March news release "Researchers from the Chinese Academy of Sciences and North Carolina State University have found evidence of preserved fragments of proteins and apparent chromosomes within isolated cell-like microstructures in cartilage from a baby duckbilled dinosaur. The findings further support the idea that these original molecules can persist for tens of millions of years.
This is significant because collagen II is found only in cartilage, while collagen I dominates in bone. Schweitzer noted that "bacteria cannot produce collagen, which rules out contamination as the source of the molecules. March 2, North Carolina State University news release. From the published paper "A nesting ground yielding dozens of disarticulated nestlings assigned to the herbivorous duck-billed dinosaur Hypacrosaurus stebingeri was discovered in the s in the Upper Cretaceous Campanian Two Medicine Formation of northern Montana.
The "study specimen had not been previously embedded in resin. Because extant primary cartilage does not usually express collagen I, no binding was expected, and none was observed in Collagen II is not produced by microbes; positing a microbial source is not parsimonious or congruent with the data. Therefore, positive PI staining cannot arise from contamination with living i.
It is sequence dependent requiring at least three successive AT [Adenine-Thymine] base pairs as a binding site. This not only supports that the compound within these cells is chemically consistent with DNA, but that material is double stranded, and of a minimum length of 6 base pairs.
Even though it is clear that contamination does exist in fossil material and complicates identifications of original organic molecules, it can be accounted for with proper controls.
Contamination is not a plausible explanation in this case". Horner, Brian K. Hall, Casey M. Holliday, Mary H. Advance access publication, 12 January Evidence of proteins, chromosomes and chemical markers of DNA in exceptionally preserved dinosaur cartilage. National Science Review, 8 pages. Michael J. He believes the DNA is from bacteria, ignoring the staining test that refutes a bacterial source by binding to DNA fragments in isolated cartilage cells, but he did say something useful: "Those studying what they believe to be ancient DNA are now careful to decontaminate their samples and work in antiseptic conditions.
But we now also know that DNA molecules break down very easily and will typically survive only a few years. Hundred-year-old samples of DNA from museum specimens are massively fragmented and the breakdown of their molecular structure continues rapidly. DNA from fossils maybe 50, years old can be reconstructed from millions of short fragments.
The oldest such samples areyears old - a long way from the 66 million year of the last dinosaurs. A study supports that conclusion, showing that, even under ideal conditions, all mitochondrial DNA bonds would be broken by 6. These results provide a baseline for predicting long-term DNA survival in bone. From: Allentoft, Morten E. The half-life of DNA in bone: measuring decay kinetics in dated fossils. Proceedings of the Royal Society B, Vol. Looking at the table, we immediately go to the 6.
But that is only if the preservation temperature is minus 5 degrees Celsius. The current global surface temperature is around The chart below shows that, in the geologic time scale since the end of the Cretaceous, the global surface temperature was 25 degrees Celsius or higher for many millions of years.
That's a different line on the table. The preservation of dinosaur soft tissue and DNA fragments points to dinosaur bones being tens of thousands, not tens of millions, years old, contradicting the geologic time scale. So do the Carbon tests:. The Data: Carbon in dinosaur bones download more details.
Dinosaur a. C Years B. USA State. Baugh and G. Detwiler; in MA Cretaceous sandstone - identified by Dr. Langston of Un. Allosaurus is a carnivorous dinosaur excavated in by the J.
Hall, A. Murray team. Hadrosaur 1, a duck billed dinosaur. Bone fragments were excavated in along Colville River by G. Detwiler, J. Hadrosaur 2, a duck billed dinosaur.
Kline team of the Glendive Dinosaur and Fossil Museum. It was sawed open by the O. Kline, H. Miller team in to retrieve samples for C testing.
Triceratops 1, a ceratopsid dinosaur. A lone femur bone was excavated in in Cretaceous clay at 47 6 18N by 39 22W in Montana by the O.
Triceratops 2, a very large ceratopsid-type dinosaur excavated in in Cretaceous clay at 47 02 44N and 32 49W in Montana by the O. Kline team of Glendive Dinosaur and Fossil Museum. Outer bone fragments of a femur were tested for C Hadrosaur 3, a duck billed dinosaur.
Scrapings were taken from a large bone excavated by Joe Taylor of Mt.
Jan 02, Dinosaur bones have been dated, based on the half life of certain elements, at millions of years. Actually, most dates for dinosaurs are done by geological column dating. Scientists see what depth the bones were found, and translate it Author: Bodie Hodge. Researchers have found a reason for the puzzling survival of soft tissue and DNA fragments in dinosaur bones - the bones are younger than anyone ever guessed. Carbon (C) dating of multiple samples of bone from 8 dinosaurs found in Texas, Alaska, Colorado, and Montana revealed that they are only 22, to 39, years old. Feb 07, Radiocarbon dating is the most accurate and most verifiable of the radiometric dating systems Sad to report: Because so many paleontologists have so long assumed that all dinosaurs became extinct many million years old, the abstract of the report by the Paleochronology group was censured, deleted from the conference website because they.
Apatosaur, a sauropod. Scrapings were taken from a rib still imbedded in the clay soil of a ranch in CO, partially excavated in an in Ma late Jurassic strata by C. Baugh and B. Bow is the bulk organic fraction of whole bone; Col is collagen fraction; w or ext is charred, exterior or whole bone fragments; Hum is humic acids. Bioapatite is a major component of the mineralised part of bones. It incorporates a small amount of carbonate as a substitute for phosphate in the crystal lattice.
Charred bone is the description given by lab personnel for blackened bone surfaces. Collagen: Proteins that are the main component of connective tissue. Yet it is found in four-foot long, nine-inch diameter dinosaur femur bones claimed to be greater than 65 million years old. The "Modified Longin Method" is the normal purification method for bone collagen. Libby, the discoverer of Radiocarbon dating and Nobel Prize winner, showed that purified collagen could not give erroneous ages.
Others should attempt to replicate these results, as two researchers did in Data from page of: Thomas, Brian, Vance Nelson. Spring
A joke about Dinosaurs and dating. Dinosaur Bones Some tourists in The American Museum of Natural History were marveling at the dinosaur bones on display. One of them asked the guard, "Can you tell me how old the dinosaur bones are?" The guard replied, "They are 65 million, four years, and six months old.". The scientific rebuttal: On the scientific side, established techniques such as radioactive carbon dating and sedimentary analysis conclusively prove that the fossils of dinosaurs were laid down in geological sediments anywhere from 65 million to million years ago. Astronomers and geologists have also demonstrated beyond any doubt that Earth gradually coalesced from a . Feb 09, Their radiometric dating analysis of rock and ash samples indicates that the dinosaurs died out 66, years ago, plus or minus 11, years. Advertisement.
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