Evaluate the evidence that Mass Extinctions are Periodic - Term Paper Example

Extinction is a reality. The research touches on extinction. The research delves on the the time period of extinction. Extinction is triggered by time period. Extinction is defined as the dying of huge numbers of animals within a short period of time. Under the Permian Triassic period, animal extinction occurred on some groups of animals. Under this period, the dying of huge group so animals is identified as “Great Dying”. The extinction occurred at 251 million years ago. The period is the middle period separating the Permian Period and the Triassic Geologic periods.

The period is known as the most severe because there were more extinctions during the period, when compared to the extinctions that had occurred during the other time periods (www.sciencedialy.com). Another time period is the Mesozoic The Meozoic period falls within the Phanerozoic time period. The Mesozoic period is divided into 3 periods. The there periods are the Triassic period, the Jurassic Period, and the Cretaceous period. http://www.sciencedaily.com/articles/m/mesozoic.htm A third time period is the Paleozoic.

The Paleozoic period is described as the geologic time scale. It is one of the four geologic time periods. The Paleozoic time period is composed of six distinct periods. The periods begin with the Cambrian period. Next, the Ordovician period crops up. Third, the Silurian period arrives. Fourth, the Devonian Period crops up. Next, the Carboniferous period creeps in. Last, the Permian period replaces the prior time period. The Paleozoic time period begins in 542 MYA to about 251 MYA. The Paleozoic period comes after the Precambrian Period.

The Mesozoic Period replaces the Paleozoic time period. The Cenozoic Time Period is divided into four classic geological years. The first is the Paleoogene period. The second period is Neogene. The paleogene is divided into four periods. The first period is the Miocene period. The second period is the Pliocene Period. The third period is the Pleistocene. The fourth time period is the Holocene. A fourth time period is the Cretaceous -Tertiary Extinction. The Cretaceous Period is one of the major divisions of the Geological timescale.

The Cretaceous period starts at the end of the Jurassic period, estimated at 146 million years ago. The Jurassic time period (which the popular dinosaur movie, Jurassic Park, was based) covers the time period from 200 Million years ago and at the end of the Triassic time period to 146 million years ago. The article Mass Extinctions : Giant Fossils Are Revolutionizing Current Thinking states the extinctions occurred from 1 million years, after the biggest extinction of all time, the Permian -Triassic extinction, had been discovered by international team (Nutzel et al. 2010). The extinction can be described as the decline in the quantity of organisms during the same time period.

The article clearly shows the different mass extinctions where biodiversity is reduced. Over the past 540 years, more than 19 mass extinctions have cropped up. The factors that triggered the mass extinctions are described as environmental conditions. For example, the change of the Ocean's oxygen level to a lower, uncomfortable conditions. Next, the change ocean's waters have become poisonous. In addition, the survival of the fittest principle forces the strong animals to wipe out the weak competitors for food.

Consequently, the present supply chain is disrupted. For example, the gastropods or bivalves could not adapt to