Radiometric Dating and the Geological Time Scale

View images by clicking on link or reduced image: Each image opens into a new window. These primitive, medium sized apes lived in rain forests between 18 and 22 million years ago. This species and others such as Dryopithecus existed before the hominid line diverged on the path to humans. This lineage ancestral gibbons is believed to have diverged from the great ape and human lineages between 17 and 25 Mya Avers, Oreopithecus ‘s hand closely matches the pattern of early hominids, with a grasping capability including firm pad-to-pad precision gripping that apes are unable to perform presumably as a response to similar functional demands to hominids Moya-Sola et al, Bipedal activities made up a significant part of the positional behavior of this primate Kohler and Moya-Sola, Gorilla and human DNA only differs by 2. Our DNA differs by only 1. The two species of Pan, the chimpanzee, P.

Dating Fossils – How Are Fossils Dated?

Dating Here of some of the well-tested methods of dating used in the study of early humans: Potassium-argon dating, Argon-argon dating, Carbon or Radiocarbon , and Uranium series. All of these methods measure the amount of radioactive decay of chemical elements; the decay occurs in a consistent manner, like a clock, over long periods of time. Thermo-luminescence, Optically stimulated luminescence, and Electron spin resonance.

All of these methods measure the amount of electrons that get absorbed and trapped inside a rock or tooth over time. Since animal species change over time, the fauna can be arranged from younger to older.

Radiometric dating or radioactive dating is a technique used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay.

A phenotypic characteristic, acquired during growth and development, that is not genetically based and therefore cannot be passed on to the next generation for example, the large muscles of a weightlifter. Any heritable characteristic of an organism that improves its ability to survive and reproduce in its environment. Also used to describe the process of genetic change within a population, as influenced by natural selection. A graph of the average fitness of a population in relation to the frequencies of genotypes in it.

Peaks on the landscape correspond to genotypic frequencies at which the average fitness is high, valleys to genotypic frequencies at which the average fitness is low. Also called a fitness surface. A behavior has adaptive logic if it tends to increase the number of offspring that an individual contributes to the next and following generations.

Accuracy of Fossils and Dating Methods

The evidence we have of Neanderthal-modern human interbreeding sheds light on the expansion of modern humans out of Africa. These new discoveries refute many previous hypotheses in which anatomically modern humans replaced archaic hominins, like Neanderthals, without any interbreeding. However, even with some interbreeding between modern humans and now-extinct hominins, most of our genome still derives from Africa.

For many years, the only evidence of human-Neanderthal hybridization existed within modern human genes. Their findings are the first to show human gene flow into the Neanderthal genome as opposed to Neanderthal DNA into the human genome. This data tells us that not only were human-Neanderthal interbreeding events more frequent than previously thought, but also that an early migration of humans did in fact leave Africa before the population that survived and gave rise to all contemporary non-African modern humans.

The CO2 Record in Plant Fossils. Plant fossils obtained from sedimentary rocks and peat deposits are a relatively new tool being used to unravel Earth’s carbon dioxide (CO2) history. Tiny pores on plant leaves and needles called stomata regulate carbon dioxide absorption and water vapor release. Stomata numbers decrease during times of high atmospheric CO2, and increase when atmospheric CO2 is.

Australopithecus africanus — The word “Australopithecus” means “southern ape. Raymond Dart, professor of anatomy at Witwatersrand University in Johannesburg, was the first to study these fossils. In at Taung in South Africa, Dart discovered a fossil skull consisting of a full face, teeth and jaws, and an endocranial cast of the brain.

The brain size was cc. Its age is currently felt to be around two to three million years old. Dart was convinced that some teeth were man-like and thus concluded a transition between apes and man. His opinions on the matter of this particular skull were largely scorned by the scientists of this time who considered it nothing more than a young chimpanzee now considered to be about three years of age.

The skull was soon known derisively as “Dart’s baby. With Piltdown Man’s human cranium and apelike jaw, it was hard to reconcile it to the Taung Child. Although Dart gave up fossil hunting for some time, all was not lost. Years after the discovery of the “Taungs child”, as it is known today, Dart and Broom found other Australopithecines at Kromdraii, Swartkrans and Makapansgat.

These finds of similar creatures seemed to vindicate Dart and Broom, and the scientific community again accepted their finds as they do today.

Creation vs. Evolution

January Fossils provide a record of the history of life. Smith is known as the Father of English Geology. Our understanding of the shape and pattern of the history of life depends on the accuracy of fossils and dating methods. Some critics, particularly religious fundamentalists, argue that neither fossils nor dating can be trusted, and that their interpretations are better. Other critics, perhaps more familiar with the data, question certain aspects of the quality of the fossil record and of its dating.

Ask us a question! Use the contact form to ask your question about our work and you may see your question — and answer — on this website, or in the ‘ Evolution FAQ’ kiosk in the David H. Koch Hall of Human .

Acknowledgements Introduction his document discusses the way radiometric dating and stratigraphic principles are used to establish the conventional geological time scale. It is not about the theory behind radiometric dating methods, it is about their application, and it therefore assumes the reader has some familiarity with the technique already refer to “Other Sources” for more information. As an example of how they are used, radiometric dates from geologically simple, fossiliferous Cretaceous rocks in western North America are compared to the geological time scale.

To get to that point, there is also a historical discussion and description of non-radiometric dating methods. A common form of criticism is to cite geologically complicated situations where the application of radiometric dating is very challenging. These are often characterised as the norm, rather than the exception. I thought it would be useful to present an example where the geology is simple, and unsurprisingly, the method does work well, to show the quality of data that would have to be invalidated before a major revision of the geologic time scale could be accepted by conventional scientists.

Geochronologists do not claim that radiometric dating is foolproof no scientific method is , but it does work reliably for most samples. It is these highly consistent and reliable samples, rather than the tricky ones, that have to be falsified for “young Earth” theories to have any scientific plausibility, not to mention the need to falsify huge amounts of evidence from other techniques.

This document is partly based on a prior posting composed in reply to Ted Holden. My thanks to both him and other critics for motivating me.

Everything Worth Knowing About … Scientific Dating Methods

Carbon , Radiometric Dating and Index Fossils Carbon dating is used to determine the age of biological artifacts up to 50, years old. This technique is widely used on recent artifacts, but educators and students alike should note that this technique will not work on older fossils like those of the dinosaurs alleged to be millions of years old. This technique is not restricted to bones; it can also be used on cloth, wood and plant fibers. Carbon dating has been used successfully on the Dead Sea Scrolls, Minoan ruins and tombs of the pharaohs among other things.

Carbon is a radioactive isotope of carbon. The half-life of carbon is approximately 5, years.

Articles in anthropology, archaeology, evolution theory and paleontology. Read the latest discoveries from archaeological sites and research institutes around the world. Images, updated daily.

Shop Now Scientists use a technique called radiometric dating to estimate the ages of rocks, fossils, and the earth. Many people have been led to believe that radiometric dating methods have proved the earth to be billions of years old. With our focus on one particular form of radiometric dating—carbon dating—we will see that carbon dating strongly supports a young earth.

Note that, contrary to a popular misconception, carbon dating is not used to date rocks at millions of years old. Basics Before we get into the details of how radiometric dating methods are used, we need to review some preliminary concepts from chemistry. Recall that atoms are the basic building blocks of matter. Atoms are made up of much smaller particles called protons, neutrons, and electrons. Protons and neutrons make up the center nucleus of the atom, and electrons form shells around the nucleus.

The number of protons in the nucleus of an atom determines the element.

Carbon-14 dating

Update – March 30, – new dates for Homo floresiensis! The new study dated layers of volcanic ash and calcite directly above and below the fossils. The bones of H. Homo floresiensis was one of the last early human species to die out. The new analysis means that this evolutionary relative became extinct around 50, years ago — just before or at the time when Homo sapiens arrived in the region. The new findings were announced by Thomas Sutikna, Smithsonian researcher Matt Tocheri, and others in the journal Science on March 30,

Creation Versus Evolution: We compare the theory of evolution with the Bible’s creation account in easy-to-understand terms, using evidence from the fields of paleontology, geology, biology, and provide links and a bibliography for those who want to study both sides of the issue.

Everything Worth Knowing About Scientific Dating Methods This dating scene is dead. The good dates are confirmed using at least two different methods, ideally involving multiple independent labs for each method to cross-check results. Sometimes only one method is possible, reducing the confidence researchers have in the results. Methods fall into one of two categories: These methods — some of which are still used today — provide only an approximate spot within a previously established sequence: Think of it as ordering rather than dating.

One of the first and most basic scientific dating methods is also one of the easiest to understand. Paleontologists still commonly use biostratigraphy to date fossils, often in combination with paleomagnetism and tephrochronology. A submethod within biostratigraphy is faunal association: Sometimes researchers can determine a rough age for a fossil based on established ages of other fauna from the same layer — especially microfauna, which evolve faster, creating shorter spans in the fossil record for each species.

Everything Worth Knowing About … Scientific Dating Methods

Explore human lineage through time: Fossils of this species, found in the Middle Awash region and the site of Gona in Ethiopia, possess derived features features different from those found in the ancestor in the skull and teeth. The postcranial skeleton of Ar. Obligate is the oppodite of functional bibedality, possessed by Chimpanzees – Pan troglodytes – for example, who can walk upright for short distances or climb in trees.

This combination of traits is important because scientists have long considered obligate bipedality to be a defining characteristic of the hominin lineage. The traits possessed by Ar.

Dinosaur fossils have been found on every continent on Earth; humans have inhabited, and continue to inhabit, every continent on Earth. Thus, it would seem that if dinosaurs and humans really did live as contemporaries at one time, as creationists contend, human fossils would have been found alongside, near, or in the same strata as dinosaur fossils.

Primary source references As a preface to this document, I want to point out that it is a shame that we have to continue to refute the same arguments that evolutionists keep bringing up over and over again in their attempts to argue against the fact of creation, which fact has been well established since the day the earth was created ex nihilo several thousand years ago. It is also a shame that the masses have bought all this based on some circular reasoning about fossils, where fossils tend to be found buried, similarities between various life forms, the presence of certain decay products in rocks, and other inherently speculative arguments about the past, based on phenomena that exist in the present.

If I hope to accomplish anything, it will be to simply encourage critical thinking. One must get past the arguments ad populum that its popularity counts for something , ad hominem that if you attack the person making the argument, this counts for something , and especially ad baculum that there are people who have the clout to decree it as true , to ask the key questions and challenge the unsubstantiated assumptions and thinking of those who would hold to the evolution position.

Today there are an increasing number of anti-creationist authors who are producing books and periodicals that make this relatively brief presentation insufficient to deal with all the points in dispute. Those defending creation today who don’t have the time to devote their life’s study to gaining expertise in all fields of inquiry must principally be prepared to think critically, logically, and challenge unsubstantiated assumptions made by these people.

They must also keep a level head in the face of some vicious attacks and diatribes that will be directed against them, as is advised in the scriptures 1 Peter 3: By way of definitions, I want to point out that when I speak of “evolution,” I am referring to the popular contemporary use of the word, which in a nutshell is the belief that all life forms are related by ancestry, and that the first life form occurred spontaneously, all due to completely natural processes.

When I speak of “creation,” I am referring to the inherently obvious fact that the origin of all life forms can be attributed to a creator who purposefully created them with planning and intent, and the documented fact that this occurred over the course of a week’s time several thousand years ago. This document is not a scientific thesis, but an apologetic intended to be submitted and defended by me in an interactive, online electronic forum.

I claim no copyright on this document, and grant its use to the public domain. I have not written it with a view towards receiving any sort of financial or other personal gain, and I request that others utilizing this document do likewise. Those copying and disseminating this document shall assume full responsibility for defending it. I do not agree to defend this document in any forum that I did not submit it, due to the practical limitations of my own time.

How Does Radiocarbon Dating Work? – Instant Egghead #28