The age of the fossil must be determined so it can be compared to other fossil species from the same time period.Understanding the ages of related fossil species helps scientists piece together the evolutionary history of a group of organisms.Most systems promoted by Evolutionists involve radioactivity.
By the way, it is important to understand that most rock strata “dates” were actually assigned long before the first use of radioactive age estimating methods in 1911.
The Carbon-14 age estimating method is, at best, only useful for estimating the age of things that are thousands of years old, not millions or billions.
Using fossils as guides, they began to piece together a crude history of Earth, but it was an imperfect history.
After all, the ever-changing Earth rarely left a complete geological record.
Measuring the uranium-to-lead ratios in the oldest rocks on Earth gave scientists an estimated age of the planet of 4.6 billion years.
Segment from A Science Odyssey: "Origins."Geologists have calculated the age of Earth at 4.6 billion years.But for humans whose life span rarely reaches more than 100 years, how can we be so sure of that ancient date? Even the Greeks and Romans realized that layers of sediment in rock signified old age.But it wasn't until the late 1700s -- when Scottish geologist James Hutton, who observed sediments building up on the landscape, set out to show that rocks were time clocks -- that serious scientific interest in geological age began.Geologist Ralph Harvey and historian Mott Greene explain the principles of radiometric dating and its application in determining the age of Earth.As the uranium in rocks decays, it emits subatomic particles and turns into lead at a constant rate.However, rocks and other objects in nature do not give off such obvious clues about how long they have been around.