Asteroid impacts can have the same effect. Absolute Time Tree rings - every year a tree grows a new ring. When the tree dies, the rings can be counted and events such as forest fires can be dated. Tree rings can be used to date events up to 3000 years ago. Varves - Layers in sedimentary rock that were formed in a lake.
Half lives differ from element to element.
When they fall apart they form a different material. Evolution Evolution is the changing pattern of life forms. Life forms will gradually change over time. Life begins as single cells about 1.3 Billion Years ago. Humans arrived about 1.6 Million Years ago.