Is Scientific Dating Reliable?

This faux amphibolite formation, found at Nuvvuagittuq greenstone belt in northern Quebec, 
may be  a portion of Earth's primordial crust. It dates to 4.28 billion years ago.
Credit: Don Francis

Alice C. Linsley

I am often asked if carbon 14 dating of fossils is reliable. People who make a habit of distrusting science point to this one method and claim that it is flawed. They seem unaware that there are many methods by which to date rocks, fossils and artifacts, and that carbon dating techniques are continuously refined. I recommend watching this video.

Even if C14 dating is wrong by 50%, we still have thousands of human artifacts that are 20 to 50 thousand years old. How can this be if the Earth is only 6000 years old? Obviously, the young earth theory has many flaws, not the least of which is the perpetuation of the idea that the Genesis creation accounts must be taken literally and Ussher's calculations using the Genesis King Lists can be used to establish the age of the earth.

Carbon 14

Fossils and rocks are dated by chemical means that rely on carbon dating which has a variance due to climate changes. Radiocarbon is continuously produced in the upper atmosphere at fairly constant levels. The radiocarbon from the atmosphere is incorporated into all living organisms on earth. Once the organisms die, the radioactive isotope decays at a known rate, so by measuring the radiocarbon levels remaining in samples scientists can work out how old things are. In the past this was done by burning a small sample of the object. Today there is a better method involving plasma oxidation chambers used to oxidize the object’s surface. This slower method does less damage to the artifact.

When molten rock cools radioactive atoms are trapped inside the igneous rock. Afterwards, the atoms decay at a predictable rate. By measuring the quantity of unstable atoms left in a rock and comparing it to the quantity of stable daughter atoms in the rock, scientists can estimate the amount of time that has passed since that rock formed.

Tree rings are also helpful in dating, but the atmospheric carbon from tree rings only goes back to about 13,000 years. That is why scientists were very excited about the sedimentary cores extracted from Lake Suigetsu in Japan. These cores extend back to 52,800- 60,000 years ago. Dating of climate changes is tracked through terrestrial core samples and also the Greenland ice cores.

With carbon dating scientists provide as accurate a range as possible. Something might be dated between 8,000 and 12,000 years old, for example. The range is because the initial amounts of radiocarbon in the environment incorporated into growing organisms vary slightly from year to year and between different parts of the carbon cycle worldwide.

Other Dating Methods

Besides radiometric dating, scientists have techniques for analyzing the breakdown of amino acids. Amino acid dating is used to estimate the age of a specimen in paleobiology, molecular paleontology, archaeology, forensic science, taphonomy, sedimentary geology and other fields. This technique relates changes in amino acid molecules to the time elapsed since they were formed.

All biological tissues contain amino acids. All amino acids except glycine are optically active, having a stereocenter at their α-C atom. This means that the amino acid can have two different configurations, "D" or "L" which are mirror images of each other. With a few important exceptions, living organisms keep all their amino acids in the "L" configuration. When an organism dies, control over the configuration of the amino acids ceases, and the ratio of D to L moves from a value near 0 towards an equilibrium value near 1, a process called racemization. Thus, measuring the ratio of D to L in a sample enables one to estimate how long ago the specimen died. The Amino Acid Racemization Dating Method has been around since the early 1970s. 

Dating is also measured by changes in an object's magnetic field. When the magma from which igneous rocks form is still molten, iron-rich minerals can orient themselves in line with the local magnetic field in the same way that a compass needle does. As the magma cools, the iron crystals are frozen in their orientation in the solid rock. This provides a record of the orientation of the local magnetic field at that time. Paleomagnetics has identified 171 magnetic reversals in the last 76 million years. Geologists developed the paleomagnetic dating technique to measure the movements of the magnetic north pole over geologic time after World War II.

By using lasers researchers can measure parent and daughter atoms in extremely small amounts of matter. This Laser Ablation Spectrometer technique is being refined by NASA for use in dating rocks on Mars. 

Another system of dating fossils is called “bracketing.” Fossils are generally found in sedimentary rock rather than igneous rock. Sedimentary rocks can be dated using radioactive carbon, but because carbon decays relatively quickly, this only works for fossils less than about 50,000 years. To date older fossils scientists look for layers of igneous rock or volcanic ash above and below the fossils. By dating these surrounding layers, they can establish the range.

This method requires understanding how the fossils are affected by geological events like rifts, erosion, folds, etc. which can disturb the layers. Scientists know what to look for to confirm dating and they give as accurate as possible ranges. A certain marine fossil may be dated to between 130,000 and 124,000 years and because it is a marine fossils, we know that the area where it was recovered was once a sea.

To determine the ages of human fossils that are millions of years, scientists need an isotope with a very long half-life. Isotopes used for this purpose are uranium-238, uranium-235, potassium-40, horium-232 and rubidium-87, all found in the human body. Each of these isotopes has a half-life of more than a million years.


Dating of Humans

Two kinds of data are needed in order to obtain a date estimate from present-day Y chromosomes: information about the genetic diversity of the Y chromosomes, and a measure of the mutation rate of the loci used to determine the diversity. Over the last two decades, Y-chromosomal studies have increasingly used Y-STRs to measure genetic diversity. The commonly used Y-STRs are variable in all populations (http://www.yhrd.org/) and mutate quickly enough that their mutation rates can be measured in deep-rooting families or father–son pairs, and refined using information from levels of population variation. Thus Y-STR mutation rates are now estimated with some precision. (Read more here.)

Mitochondrial DNA L groups are extremely archaic. In human mitochondrial genetics, L is the mitochondrial DNA macro-haplogroup that is at the root of the human mtDNA phylogenetic tree. As such, it represents the most ancestral mitochondrial lineage of all currently living modern humans. All modern humans have ancestry that is traced to Africa.

Of special interest to biblical anthropologists is YDNA Haplogroup R1. YDNA R1b is found widely in Africa, the Middle East, Southern Europe, Spain, France, and the British Isles. The dispersion of R1b peoples took place over thousands of years, beginning about 20,000 years ago. Most biblical populations are in this haplogroup. Abraham's ancestors came out of central Africa near Lake Chad and the Upper Nile. Note the dark red spots in those places. The dark spot in central Africa is the region of Lake Chad, Noah's homeland.

Dating Scripture

Dating the Bible is as much a science as dating fossils and rocks. There are few methods that render absolute dates and scholars who study manuscripts likewise date material by giving ranges. One attempt to scientifically date the Pentateuch relies on a chronology established through synchronisms dated by astronomy. The ranges of time for the older Biblical material tend to be greater than for the more recent material. The dating of New Testament books cannot be set with absolute confidence so scholars often give a range, but the range is a matter of a few years or a decade, not a thousand years as is more often the case with the material in Genesis and Exodus. For example, the book of Romans is typically given a range of A.D. 56-58. In the dating of the books and events described in the Bible scholars rely on data found in the Bible and on extra-Biblical sources to help narrow the range. Archaeology, anthropology and linguistics have been especially helpful sciences in the service of Biblical scholarship.

Related reading: Many Groups of Archaic Humans; 1.5 Million Year Foot Print in Kenya; Radio Carbon C14 Dating; Lake Suigetsu and the 60,000 Year Varve Chronology; Dating the Five Books of Moses In Defense of Biblical Anthropology; A Scientific Timeline of Genesis; Gap Theory or Gap Fact?

Rising Star Expedition Recovers Hundreds of Fossils

Amazing team work to recover hundreds of human fossils is described by caver Rick Hunter, a member of Lee Berger’s team in the Rising Star cave system in South Africa. Hunter guides and supports the scientists, "standing sentry in the caverns, and on the long journey from daylight into the caves, through winding passages, a belly-crawl tunnel, up a jagged rock-climb, and down the final 12-meter vertical crack that leads to the fossil chamber below." Read Hunter's reflection in the National Geographic report The Journey into Darkness.

Lee Berger holding his most famous fossil find, a crania of Australopithecus sebida.
This fossil was found in the vicinity of the Rising Star system of caves.

Here is an excerpt from John Hawks' What We Know and Don’t Know So Far:


After a week of running the operation, the advance scientists have fallen into a rhythm of approximately half-day shifts, staged into and out of the cave on a rotation. The first cavers go in around 7:15am, the last come out after 4:00pm. Getting into this cave requires several experienced cavers in place to assist the advance scientists entering and leaving the advance chamber. Some serve shifts inside the cave at key locations where they can support the scientists. Others are on hand at the cave entrance to run supplies in and fossils out. And the science team and command team are aboveground coordinating action and cataloguing and conserving the fossils.

We saw the incredible teamwork in action on Friday evening, as more than a dozen of the cavers and advance team carefully brought out a large skull fragment. Two scientists and two cavers staged it carefully up the Chute, seven handed it down Dragon’s Back, three more brought it through the Post Box — at the end with one scientist pulling our expert caver Rick Hunter through by the legs. All of this without so much as tipping the box containing the fossil.

Related reading:  Science in Progress: The Rising Star Expedition in South Africa;  A Geologist on the Rising Star Expedition

Meet Kamoya Kimeu, Fossil Hunter

Kimeu with journalist Heeren

Finding Hominids with Kamoya Kimeu

Journalist Fred Heeren with Kimoya Kimeu

-by Fred Heeren

Kamoya Kimeu is not known for his religious views. Many know him for his narrow escapes from lions, crocodiles, and cobras—and many more as East Africa’s preeminent fossil hunter, perhaps the most successful discoverer of hominid bones in the world.

Paleoanthropologists have a running argument about whether fossil prospectors are better prepared for the job from textbooks in academia or from expert collectors in the field, where they learn skeletal anatomy by handling bones and fragments. Kimeu makes a strong case for the latter.

In addition to finding hominids with Louis and Mary Leakey (starting in 1959) and their son Richard (becoming his right-hand man in 1963 and taking control of field operations in Richard’s absence in 1967) and his more recent field work with daughter-in-law Meave Leakey, Kimeu found now-famous hominid specimens while prospecting with Tim White, Alan Walker, Kay Behrensmeyer, and Andrew Hill. In 1977, the National Museums of Kenya appointed him curator for all of Kenya’s prehistoric sites.

Kimeu’s field-trained eyes were the first to spot the bits of fossils leading to the discovery of the earliest Homo sapiens skull (Omo I), now dated to 195,000 years ago. He discovered the 1.5-million-year old Turkana Boy, the most complete skeleton of the small-brained-but-tall-bodied Homo erectus.

Read it all at God and Nature Magazine.

Darwin's Doubt

To those unfamiliar with the particular problems faced by scientists trying to explain the origin of life, it might not seem obvious why invoking natural selection does not help to explain the origin of the first life. After all, if natural selection and random mutations can generate new information in living organisms, why can it also not do so in a prebiotic environment? But the distinction between a biological and prebiotic context was crucially important to my argument. Natural selection assumes the existence of living organisms with a capacity to reproduce. Yet self-replication in all extant cells depends upon information-rich proteins and nucleic acids (DNA and RNA), and the origin of such information-rich molecules is precisely what origin-of-life research needs to explain. That’s why Theodosius Dobzhansky, one of the founders of the neo-Darwinian synthesis, can state flatly, ‘Pre-biological natural selection is a contradiction I terms.’–Stephen C. Meyer (Darwin’s Doubt, p. viii)

There is a fascinating new book from Dr Stephen C. Meyer, a Cambridge graduate, and Director of the Center for Science and Culture in Seattle, Washington.

Darwin's Doubt appeared in June 2013 and is available on Amazon. Meyer's book provides a comprehensive analysis of the challenge to paleobiologists of explaining the sudden appearance in the fossil record of numerous new life forms without any obvious ancestors. This is often called the "Cambrian explosion."

In Meyer's view, the fossil record does not align with the Neo-Darwinian explanation of evolution. The hugely complex steps required to generate new body plans through gradual and random changes seems doubtful in light of the sudden appearance of both simple and more complex organisms.

I address this from a different angle in Does the Binary Feature Signal Greater Complexity?

It takes courage for a scholar to question the dogma of random mutation, natural selection and common ancestry, and if you read the reviews of Meyer's book, you will discover just how angry his reasonable arguments have made some Neo-Darwinians.


Related reading: Thomas Nagel: Neo-Darwinian Conception is False; Questioning the Common Ancestry Hypothesis; Darwin: Fact and Fiction

Earth's first fossils neither vegetation nor animal

Diskagma buttonii fossils are the size of match heads and were found connected into bunches by threads in the surface of an ancient soil from South Africa. (Credit: Courtesy of Gregory Retallack)

Conventional scientific wisdom has it that plants and other creatures have only lived on land for about 500 million years, and that landscapes of the early Earth were as barren as Mars.

A new study, led by geologist Gregory J. Retallack of the University of Oregon, now has presented evidence for life on land that is four times as old -- at 2.2 billion years ago and almost half way back to the inception of the planet.

That evidence, which is detailed in the September issue of the journal Precambrian Research, involves fossils the size of match heads and connected into bunches by threads in the surface of an ancient soil from South Africa. They have been named Diskagma buttonii, meaning "disc-shaped fragments of Andy Button," but it is unsure what the fossils were, the authors say.

Read it all here.