We do this all the time in our regular day to day lives.
For example, lets put the following movies in order of relative age from oldest to youngest: Twilight, Finding Nemo, the Avengers, the Hunger Games.
Second, it is possible to determine the numerical age for fossils or earth materials.
Numerical ages estimate the date of a geological event and can sometimes reveal quite precisely when a fossil species existed in time.
Layers of rock are deposited horizontally at the bottom of a lake (principle of original horizontality).
Younger layers are deposited on top of older layers (principle of superposition).
For example, in the rocks exposed in the walls of the Grand Canyon (Figure 1) there are many horizontal layers, which are called strata.
" First, the relative age of a fossil can be determined.
Relative dating puts geologic events in chronological order without requiring that a specific numerical age be assigned to each event.
This is the principle of original horizontality: layers of strata are deposited horizontally or nearly horizontally (Figure 2).
Thus, any deformations of strata (Figures 2 and 3) must have occurred after the rock was deposited.
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.