I. Mass Extinctions Paleontologists have been able to identify patterns within and between extinction events. In his book entitled Extinction , Steven M. Stanley has outlined the five major extinction patterns recognized. The following process has helped paleontologists determine the agents that may have caused the disappearances of species.
Extinction arises in both the land and the sea.
On land, while animals suffer repeatedly, plants tend to be highly resistant to mass extinctions. There is preferential disappearance of tropical forms of life during mass extinctions. There is a tendency for certain groups of animals to experience mass extinctions repeatedly. Although the following agents can explain mass extinction, the causes of minor extinction events remain relatively unknown. The direct mechanisms of extinctions include habitat loss and fragmentation, invasion by introduced species, pollution, global climate change, and industrial agriculture and forestry.