Radioactive dating methods contribute to the study of evolution
It excludes contamination and weathering of travertines and makes possible more precise dating of thin deposits of secondary carbonates.
No web-based resource for this method is available.
Keyed to the relative time scale are examples of index fossils, the forms of life which existed during limited periods of geologic time and thus are used as guides to the age of the rocks in which they are preserved.
William "Strata" Smith, a civil engineer and surveyor, was well acquainted with areas in southern England where "limestone and shales are layered like slices of bread and butter." His hobby of collecting and cataloging fossil shells from these rocks led to the discovery that certain layers contained fossils unlike those in other layers.
Hutton, a Scottish geologist, first proposed formally the fundamental principle used to classify rocks according to their relative ages.
He concluded, after studying rocks at many outcrops, that each layer represented a specific interval of geologic time.
Trees from the same species, growing in the same area or environment will be exposed to the same conditions, and hence their growth rings will match at the point where their lifecycles overlap.
Earth's oldest living inhabitant "Methuselah" at 4,767 years, has lived more than a millennium longer than any other tree.
Please remember that all dating methods, even those termed "absolute," are subject to margins of error. That is a very small amount of possible error range. Modern studies almost always use two or more methods to confirm dating work and to build confidence in the results obtained.The most compelling argument for an age of the earth of 4.5 billion years are the large number of independent tests that have been used to confirm this date.These tests have been performed on what are thought to be the earth's oldest surviving rocks, meteorites, and moon rocks.Dating is not necessary to demonstrate that evolution is a fact.Chronological sequence is all that is really required.