Seriation uses the assumption that once a tool was developed, its use would become more widespread.Stratigraphy uses the assumption that higher layers or strata were laid down after lower layers.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.
The various methods of relative dating are; This method depends on the common observation that the height of the habitational area increases as the people continue to live at the same place.
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.
Stratigraphy is the oldest of the relative dating methods that archaeologists use to date things.
Stratigraphy is based on the law of superposition--like a layer cake, the lowest layers must have been formed first.