Most people have at least a passing level of knowledge in the primary non-molecular evidence area of evolution—the study of fossils.
8. Chronology-Fossil and Stratigraphy, Radioelement Dating:
There are two major methods of dating the age of the earth and its inhabitants: Relative dating and numerical or radiometric dating.
Relative dating places fossils in a relative temporal sequence by noting their positions in layers of rock or strata (The Law of Biotic Succession which states that fossils in a stratum will always occur in the same sequence regardless of geographic location, i.e. rocks with the same fossils are of the same age wherever they are found.). 
Based on empirical data, predictions from physical law (gravity), and actual findings, undisturbed deeper strata are presumed to be older than more superficial strata by superimposition (The Law of Superposition). Flaws in the methodology reflect the fact that some layers do not lay horizontally, even at the beginning or because layers were disrupted by being overturned in movements of the earth. To compensate, three methods of dating are utilized—faunal succession, crosscutting relationships, and inclusions—comparing strata from all around the world, presuming that clearer stratification in one area will suggest a similar age in another area. As a matter of work-a-day efforts for geologists, paleontologists, and evolutionists, it is regularly observed that organisms are more similar the closer they are in rock strata and more dissimilar by decrements the farther separated they are from each other.
Numerical or radiometric dating relies on the random pattern of decay of unstable radioactive elements such as uranium (half-life of less than a second), plutonium (half-life of 24,000 years), potassium (half-life of 1.25 billion years), potassium-argon (K-40 decays to Argon 40 which can be measured), rubidium (half-life of 4.9 billion years), and carbon 14 (half-life of 5,730 years) which have a measurable half-life. Carbon 14 is accurate for up to about 20,000 year old specimens, but is only partially accurate for biologicals back to 40,000 years ago. Active elements decay at regular rates irrespective of conditions. Half of the U-238 in rock will be left at 4.47 billion years; half of the remaining U-238 will remain in another 4.47 billion years. Volcanic eruptions produce especially rich radioactive materials. Measurement of the time-frame of existence of fossils found between layers of different layers of volcanic ash permits especially accurate time determinations. Association with species’ fossils which have a known age, helps to determine the age of a newly discovered fossil.
Rocks brought back from the moon have been dated to between 4.4 and 4.5 billion years ago. The oldest solid substances found on earth are zircon crystals that were formed 4.4 billion years ago. It is postulated that an asteroid the size of Mars struck the earth and scattered debris that later coalesced to form the moon. Very old rocks—the oldest, found in Greenland, is 3.9 billion years—and the oldest meteorites, suggesting the age of the earth is 4.5-4.6 billion years old) are dated using volcanic material which gives a relative age—older rocks below and younger rocks above a layer of volcanic ash or by inference from fossils in rock strata. Sedimentary rocks less than 40-50,000 years old can be dated using their radiocarbon content. After many decades of work around the world, geologists have assembled a reliable geological time scale on the basis of radiometric dating. Despite innate errors of radiocarbon 14 dating of 10-20%, a good rough estimate of relative age of objects less than 50,000 years old is possible.
Less major methods, utilized for more difficult to categorize specimens (no volcanic ash, no radioactive materials), include optically stimulated luminescence, measuring how long a specimen of sand or dirt has been away from light, is a new technique that is proving to be useful. Electron spin resonance, which measures how much radiation damage has accumulated in a fossil is another recent technique that can help determine a fossil’s age.
The earliest suggestion of life on earth in geological formations is layered rocks known as stromatolites that were probably the result of the actions of bacteria at least 3.4 billion years ago (BYA). Fossils, i.e. those found in the oldest strata, suggest the existence of worm-like creatures a billion years old. Soft bodied multi-cellular organisms, are dated to between 635 to 540 million years ago (MYA) and are likely intermediate forms between the single celled organisms that lived in the first 1-2 billion years after the formation of the earth and the first hard-bodied creatures that appeared in the sedimentary fossil record beginning about 540 MYA. There is a notable transitional form between fish and early tetrapods that lived on land. It appeared in the fossil record dated to about 375 MYA.
Fossils from about 315 MYA document the evolution of large amphibians from the early tetrapods. Rocks bearing the skeletons of dinosaurs began to appear about 230 MYA, and they were intermediate forms which evolved from reptilians found in earlier sedimentary layers. Another lineage from reptiles found in the sedimentary fossil record lead to mammals between 250 and 200 MYA. Archaeopteryx, a 150-155 million year old fossil that has the skeleton of a small dinosaur but also has feathers and wings, is an intermediate form between dinosaurs and creatures found in China and dated to 110 MYA that have smaller tails and clawed appendages. In more recent fossils, located in ever more superficial layers have been found evolutionary intermediate specimens leading to modern organisms—from apes and whales to elephants, armadillos, and humans. One branch of the mammalians–the primates–began to appear between 60 and 80 MYA. The most recent species ancestral to both humans and chimpanzees lived 6-7 million years ago. Therefore, technically, man did not “descend” from apes, especially chimp-anzees, but chimps and man had a common ancestor which no longer exists from whom they both evolved separately.
An ingenious method of checking the accuracy of radiometric dating was devised by John W. Wells of Cornell University (Coral Growth and geochronometry, Nature 187:948-950, 1963). Dr. Wells studied fossil corals which lived in the Devonian Period, about 380 MYA according to radiometric dating studies. He made use of an established physical/geological fact that tides create a friction which gradually slows the earth’s rotation over time. That results in each revolution of the earth around the sun—one day—taking a miniscule bit more time that did the previous day. The result is that every 100,000 years the length of a day increases by about two seconds. However, the length of time that the earth takes to rotate around the sun—one year–does not change. This results in the number of days per year decreasing over time. Using the known rate of decrease in the number of days per year, Dr. Wells worked backwards from a putative date by radiometric measurement of 380 MYA when the corals were alive to the present.
If the tidal friction, number of day shortening predictions were correct, he theorized, then each year would have contained 396 days, each 22 hours long. Corals were an excellent study material because they maintain an ongoing record of their lives by having daily and yearly rings. The researcher need only count the number of daily rings between each yearly ring accumulated when the coral was alive to determine the number of days per year. Wells counted the rings—the tidal age–and cross-checked them against the radiometric data. The Devonian corals experienced roughly 400 days per year with each day being 21.9 days in length, a very small deviation from the predicted 22 hour days. The correlation between tidal and radiometric age was extremely close, hence scientists have strong confidence in the data they glean from radiometric studies.
Direct observation of ancient phenotypes may be taken from fossils, which provide unique information on entirely extinct groups of organisms, and are usually associated with stratigraphic information pertaining to relative and absolute geologic ages. Nonetheless, the fossil record has many well-known shortcomings, including the famously incomplete levels of preservation, and usually very limited information about the nature of soft tissues such as hearts, nerves, and brains. continued…