Radiometric dating evidence for evolution?

Question

I can understand how it's evidence against some creationisms, but how is evidence FOR evolution?

Answer 1

It isn't.

It *is* however evidence for the ages of certain rock strata.

And one you age rocks, and compare the morphologies and abundances of fossils found in them, then there is a clear pattern of what organisms and body types are found when. And a picture of the evolutionary history of the world can be constructed (no rabbits in the precambrian era, for example).

Answer 2

The age of Earth was one of Darwin's biggest problems for his hypotheses of descent with modification and natural selection. Early 19th century science had no reason to suppose that Earth's age was very different from Bishop Ussher's estimate of 6,000 years. For the naturalists who mused about evolution before Darwin's day, there was simply no rational way to account for earth's diversity in such a short span of time. Darwin remained stuck here as well until he read Charles Lyell's "Principles of Geology" while voyaging on the Beagle. Lyell's ideas supported an ancient Earth and, based on this geology, Darwin estimated that an earth several hundred million years old gave evolution enough time to produce the living diversity that he was aware of.

The age of Earth has always been hotly disputed (at least from the creationists' point of view), and it was one of the first falsifiable aspects of the theory of evolution to be scientifically tested. If you can prove earth is relatively young or that fossils are not truly ancient, then evolution is out the window. Thus any method that accurately (and anciently) dates Earth and the age of fossils, lends support for the great span of time required by natural selection.

In fact, immediately after Darwin published "Origin of Species," the well-known physicist Lord Kelvin (William Thomson) used his calculations for the age of the Sun to dispute Darwin's age for Earth. The physics of the Victorian Age could not account for an Earth more than 20 million years old - unless some extremely powerful energy source was hiding from them. Geologists were also skeptical and would not accept an age for Earth above 100 million years.

It wasn't until the early 20th century that we learned enough about the nuclear reactions within the sun to finally settle Lord Kelvin's dispute - in Darwin's favor. The geologist's came around by 1911, after Arthur Homes first used uranium-lead radiometric dating to date rocks to more than 300 million years old. In 1913, Homes estimated the age of Earth at 1.6 billion years; by 1946, he had put it at 3+ billion years. Later work in the 1950s pushed this figure to over 4.5 billion years.

http://www.strangescience.net/holmes.htm

http://www.csicop.org/sb/2003-06/reality...

Answer 3

Radiometric dating is just one method of to indicate the age of fossils.  I have copied a nice, relatively short explanation here... (Source at the end.)

"In radiometric dating, scientists look at the ratios of naturally occurring radioactive isotopes (atoms that carry an electrical charge) found in igneous rocks. These unstable radioactive isotopes decay to non-radioactive elements at constant rates, known as the element's "half-life". This means that after the time of the half-life, half of the radioactive isotopes would have decayed to the non-radioactive form; so the ratio of radioactive to non-radioactive element would be 50:50. After another half-life, one-half of the remaining radioactive isotopes would have decayed to the non-radioactive element; so the ratio of radioactive to non-radioactive element would now be 25:75. (Half of the 50% remaining radioactive isotope decays, leaving half of it, or 25% of the original element, as radioactive, and the other half, 25% of the original element, as non-radioactive.)

A type of radiometric dating that you might have heard of before is Carbon 14 dating or Oxidizable Carbon Ratio Dating, often simply called "carbon dating". Naturally occurring Carbon 14 decays to Nitrogen 14, with a half-life of 5,730 years. Because Carbon 14 has such a short half-life, it is useful in archaeology for dating artifacts (man-made objects) and the bones of animals up to 50,000 to 60,000 years old. However, it cannot be used on anything older than Middle Pleistocene Epoch in age.

In order to date older fossils, scientists must use other radioactive isotopes. A commonly used technique is called Potassium-Argon dating. The element potassium is found in most rock-forming minerals, and the half-life of the radioactive isotope Potassium 40 is 1.25 billion years, allowing measurable quantities of Argon 40 (its decay element, known as the daughter element) to accumulate in potassium-bearing minerals of almost all ages. The amounts of potassium and argon isotopes can be measured accurately, even in very small quantities, making Potassium-Argon dating useful for both very young and very old rocks (and everything in between).

Although radiometric dating is much more precise than relative dating, it does have its drawbacks as well. With the exception of Carbon dating, radiometric dating can only be used on igneous rocks, not sedimentary rocks or the actual fossils. Because fossils are found in sedimentary rock, paleontologists have to use radiometric dating information on igneous rocks found below and above the fossils in order to determine an age range for the sedimentary rocks. "

The important concept here with regard to proving evolution is that it is an accurate method of determining  the ages of different types of fossils being studied by paleontologists and thus dating the ages of the fossils contained within them.  It demonstrated the concept of evolutionary changes over time in which we see simpler organisms in older strata progressing to more complex ones as time progresses. If we were ever to find the reverse...i.e. a mammal fossil or flowering plant fossils in  425 million year old rock... (before they are thought to have evolved) scientists would have to radically rethink their ideas on evolutionary history...but these discrepancies are not found. Radiometric dating is one of many tools that have been used to evaluate the age of fossils and demonstrate the accuracy of our understandings of evolution and evolutionary theory.

Answer 4

^ jim, you really have no idea what you're talking about.

Radiometric dating DOES have unrelated standards to correlate against.  Milankovich cycles, for one non-radiometric source.  Additionally, as all radiometric techniques use different isotopes, they are independent of one another and provide correlation for each other.  If there was a flaw in the method, there is no way that the many different types of dating would correlate with one another.

Look at Hawaii.  The islands are forming over a hot spot that moves at a predictable rate, and the age of the islands as determined by this tectonic method correlates to the age given by radiometric methods.

In short, you've been reading some of that creationist propaganda and you've fell for it.  They're lying to you, jim, and they're manipulating your beliefs for their own power.

You think that you can find evidence for any viewpoint, it just matters what your interpretation is.  But you're wrong.  You'll never find any unambiguous, empirical evidence for creationism, and you saying 'There is more logical, conclusive, and congruent evidence for creation than one would need' is not going to make it so.  People have been trying to find evidence since before science was created.  The first biologists and the first geologists were all creationists.  They didn't come to the conclusions of 'billions of years' and 'evolution' because of their viewpoint, they came to those conclusions because of the _evidence_, and they changed their viewpoint accordingly.

ANYWAYS to answer the actual question here :)

Evolution predicts that, when fossils from a certain lineage are found, more primitive fossils will be older then more advance fossils.  Radiometric dating confirms these predictions, thus amassing evidence for evolution.

If one was to find a trilobite fossil that dated to 50,000 years ago, or a rabbit fossil that dated to precambrian times, that would falsify evolutions prediction.  Falsifiable predictions are good, that's what we want in science, and that's how we get evidence.  So the age of fossils is the falsifiable prediction, and radiometric dating allows us to test that.

Answer 5

Fennec,

Radiometric dating, by itself, is not necessarily evidence for evolution. But together with fossil samples that have been gathered from rocks that have been radiometrically dated, it is powerful evidence for evolution.

The radiometric dating of the geologic column, by itself, does not indicate biological evolution. It indicates rather conclusively that the earth is about 4.5 billion years old and that rocks have been created and deystroyed almost continuously during that time, but it does not indicate biological evolution.

However, this rock record also contains a series of fossils that goes from very simple life forms in the bottom-most, oldest rocks, all the way to modern life forms in the top layers of rock that give the youngest radiometric ages. Intermediate stages of life are even preserved in suprising detail throughout the geologic column. All of this fits together like puzzle pieces to show a story of life beginning, evolving, diversifying, and becomine the array of organisms that we see today.

Answer 6

It can somtimes be used to date localities.  Localities which are earlier or later deposits tend to yield fossils of different plants and animals, and that succession can provide evidence of evolutionary change over time.  To put it in very generalized and bland terms.  Say one earlier site only yields lemur-like primates, a later site in the same area yields both lemur-like and monkey-like primates, and a still later locality yields lemur-like, monkey-like and ape-like primates.  That could indicate evolutionary radiation of primates.

In practice, most localities aren't dated on the basis of radiometric dating, as the can't be, and radiometric dating is only one set of methods among other sets of techniques used.  Researchers are keen on getting the correct date, rather than simply one they're hoping to obtain, and lots of different strands of evidence are taken into account.

Answer 7

Obviously if you're going to put together a theory that lifeforms have been changing and adapting over a long period of time, you're going to want to put together a kind of time line for that change.

Radiometric carbon dating allows you to tie a particular fossil to a period in time. You can place the fossil on the time line, and with enough such data points, you can construct a fairly convincing demonstration that species are, in fact, changing over time.

Answer 8

I guess I will be the only ignorant one here to stand up for Creation, so far.

First, If you see someone claiming that carbon dating is used for fossil dating, you can pretty much throw out that persons arguments, or at least look very carefully and assume that the person is just quoting some text from a book supporting evolution and not really understanding the complexities of this subject. Carbon dating is not used on fossils. Only on tissue samples of  plants or animals, and only going back about 50,000 years. (per evolutionary estimates)

Also you can disregard my statements because I am no expert either, but I think that no one on here is, they just learned a couple chapters in a textbook and are quoting it. A person has to realize that this subject is not that straight forward.  There is two sides, and the evolutionarly presented side does not flaunt its weaknesses.

Here are a couple of things to think about.

First, Scientists would like us to believe that Radiometric dating is an independent measurement. This would greatly validate their theory of evolution. It is not an independent measurement though.

When we measure distance, there is a standard. It used to be an actual artifact held somewhere which all other measurements where to be measured up against. Now it is a calculation of the distance light travels in a given time. We can see that if I measure my desk and come up with 56 meters, I may have a problem. How do I verify?  I check the standard.

Now if I radiometric date a rock layer and come up with a strange measurement how would I know? I use evolutionary assumption to verify, so I date the evolutionary asumption with a technic and I verify the technic with the assumption. Thats circular reasoning. Also the assumption is used in the very process of gathering and calculating or calibrating the measurement. Look up the contriversy behind the KBS Tuff for examples of this. This is just on on the published examples, I'm sure many others are not published.

Second. To put the first part into context think about this. If I bring a piece of limesone to your lab and ask you to date it, you will not be able to. You must know what "index fossil" was assosiated with it.

Third. The Coelacanth was a transitional index fossil that was used to date rock layers. The fossil probably was found near the bottom. (I don't know where all the fossils where found but I am assuming) The evolutionary assumption was that the Coelacanth was the transition from water to land because of its lobed fins. The accepted dates if the layer was dated would have to be no younger than 65 million years old.

They started finding the coelacanth still alive in some parts of the world. My question would be. How do you know that the ones living 20,000 years ago weren't making the fossils you were discovering. The fossil was found near the bottom you say, that is because the fish live in the water, the water is always the lowest elevation. Then amphibians, so on and so on.

Fourth. I saw on the discovery channel where some scientist were all exited because they found some fossils that they say were pre-cambrian. They were fossil impressions of organisims that looked like they would fit into the progression from simple life to complex invertibrates. This was a major discovery. The fossils were found in a piece of rock that was on a cliff next to the ocean. The fossils that they found were exposed. The scientists had to take their shoes off to walk on the rocks for fear that they would damage some of the fossil impressions. My question is, how could the fossils be exposed for who knows how many millions of years to the ocean side erosionary forces, but you have to take your shoes of for fear of damaging them?

I realize that the rocks where not exposed the whole time (over 500 million years) but they would probably have to be exposed for many many millions of years.

Fifth. They are now finding blood and tissue in dino fossils (over 65 million years old) and I saw an article of 250 million year old bacteria that came back to life. They say this because the evidence must still fit into the evolutionary pylogenetic progression. The blood and the bacteria are not "big" enough to overturn the assumptive date progresson and any ratiometric dates are not either. They only print the ones that they can get to "fit" their needs.  It's called propaganda.

If you think that a cow, an acorn, a bee, a human, a slug, a starfish, and a bacteria are all related you fell for it hook line and sinker.

Sixth. God loves us and he has provided a redemptive plan through Jesus Christ. The world doesn't want God and it never will. You don't have to be a part of that. Whatever the "powers that be" on this earth would want to say is the scientific truth, with enough funding they could find enough evidence for it. If you want evidence for God all you have to do is look. There is more logical, conclusive, and congruent evidence for creation than one would need.