They are considered so because are the indispensable parts of the nature cycle.Without formation,decay cannot be possible and similarly,formation cannot be possible without decay.In addition to this,THEY ARE IN A CHRONOLOGICAL MANNER SET BY NATURE and that's why cannot be seperated and so together constitute the cycle of nature.
Well he looked at the contents and saw they some of them had similar shapes so
The answer is; fossil
Fossil is defined as any dead organism ( or its trace or impression) of a past geological time that is naturally preserved in the earth in geological features such as rocks, bogs, and etcetera. Coral reef is no exception because it is considered a living organism. It is composed of colonies of coral polyps and algae that secrete a carbon carbonate skeleton.
The hypothesis that all modern humans descended from an African lineage is supported by the mitochondrial DNA evidence. The Eve hypothesis is the hypothesis that is based on the study of mirtochodrial DNA; that modern humans have a common female ancestor who lived in Africa around 200,000 years ago. It is also called African Eve hypothesis.
