Tuesday, April 13, 2010
The Dating of Fossils
The age of fossils are critical for outlining evolution as with the age of fossils we are able to prove not only that the world has been around longer than the young earth creationists believe but also to plot the timeline of evolution and observe how and why animals evolved. As carbon dating as the generally accepted and most common way of defining the age of fossils seems more and more questionable with the nuclear bombs and testing that occurs around the world, what will be the next way to determine the age of fossils? If we are not able to determine the age of fossils, how will we continue to pursue the dream of following the footsteps of evolution? Will we even still be able to chase the proof of evolution? What will happen to the theory if we can't assign a definite time to each fossil we find? Would the whole theory just collapse without time reference?
Subscribe to:
Post Comments (Atom)
The carbon dating method is currently used most often in order to date the fossils that are currently found. This method is by utilizing the decay of radioactive elements that are inside rocks. They elements decay at a constant rate and by determining the half-life of the rock, the age can be predicted. Carbon-14 is commonly found in wood, bone, or human artifacts in order to pinpoint age.
ReplyDeleteLet's say a nuclear holocaust happened causing the entire world to fall in turmoil. The first thing I'd ask is why people are still looking for fossils when the earth is obviously doomed but for the sake of this question I'll continue. There is a possibility that the radioisotopes found in rocks won't be affected by atomic bombs. Scientists have already tried exposing isotopes to extreme temperatures and pressure and the resulting half life is unchanged. In this scenario, although scientists probably haven't been able to replicate an atomic bomb pressure level, radiometric dating could still be applicable.
If radiometric dating is unavailable, there are other methods. One such is called relative dating or superposition. This utilizes the location to which the fossil was found, and by observing the nearby sediments, the relative age can be predicted. This is also compared with a different area's sediments, and by comparing the composition of the strata layers, an age can be predicted.
Even if no other age identifying method was found, the theory of evolution would still be able to run on the evidence is has accumulated to this point. Although a lot of evidence does come from directly analyzing fossils and such, evolution is also observed in the genome of animals, such as vestigial traits. Pseudogenes also seem to point to the theory of evolutionary. Fossils do play a primary role in evolution, however, it is not the only source of evidence that is presented.
Sources:
http://paleo.cc/kpaleo/fossdate.htm
http://www.darwiniana.org/datingmethods.htm
Why Evolution is True
While atomic bombs present a problem, they also present a solution. The world changed at the dawn of the atomic age. When the first atomic bomb was detonated, it released radioactive Cesium-173. This is an isotope the world had never seen before 1945. This fact makes it a good way to test antique wine bottles for authenticity. I learned this on an episode of White Collar entitled "Bottlenecked". The significance is that all wine bottled after 1945 has trace amounts of Cesium-173. Further research through the EPA confirms the USA network's research.
ReplyDeleteThe application to evolution is limited. We can still use it to date remains, but only relative to 1945. It's a good way to test fake fossils, at least. The concept is still applicable using other elements.
Cesium gets into the body by ingestion or inhalation. Many other elements enter the body in the same way. In order to make inferences, we need to know what the air was like on earth at the time the organism lived. This is where Ice Cores come into play. Every year, another layer of ice is added to the poles. Air bubbles from the snow get trapped in the ice and can be examined by scientists. My proposition is to use our knowledge of geology to estimate a fossil's age. Then, we can compare the composition of the fossil with the composition of the air around that time period. This currently gives us around 200,000 years of reference. Trends in known fossils should follow trends in the air.
In this way, the bubbles are acting miniature wine bottles. Since the wine (air) is trapped inside, it won't be affected by the atomic activity of the atomic age.
EPA
http://www.epa.gov/rpdweb00/radionuclides/cesium.html#wheredoes
White Collar
http://preppiesoftheapocalypse.blogspot.com/2010/02/white-collar-bottlenecked.html
Ice Cores
http://www.gisp2.sr.unh.edu/MoreInfo/Ice_Cores_Past.html