Radioactive dating geologic time scale
After that, you can ask any crowd, anywhere, anytime.
Despite seeming like a relatively stable place, the Earth's surface has changed dramatically over the past 4.6 billion years.
Species adapt when succeeding generations emphasize beneficial characteristics.
Few discussions in geology or evolution can occur without reference to geologic time.
As these changes have occurred, organisms have evolved, and remnants of some have been preserved as fossils.
A fossil can be studied to determine what kind of organism it represents, how the organism lived, and how it was preserved.
In this article, the standard time scale used by geologists is depicted and described.
See also Niel Brandt's Evolutionary and Geological Timelines.
For example, based on the primate fossil record, scientists know that living primates evolved from fossil primates and that this evolutionary history took tens of millions of years.
...calculation was based on the assumption that the substance of the Earth is inert and thus incapable of producing new heat.