Evolution Was Introduced By Charles Darwin

1698 WordsMay 11, 20167 Pages
The idea of evolution was introduced by Charles Darwin, and explains how animals change over time. The theory states that every organism on the Earth originated from a common ancestor and then, through the process of natural selection, how those animals branched off to become different organisms. Scholars use this theory to explain how animals that live on Earth change over time. However, scientists find it difficult to use this theory to explain some events that occurred in the geologic time period, such as the Cambrian Explosion. The Cambrian explosion was a macro-evolutionary event that happened during the late Ediacaran and early Cambrian period. It introduced a number of phyla on the Earth, and significantly affected the animal…show more content…
When a mass extinction takes place, the dominant species of that time get removed, enabling other organisms to use the resources they once did. This means that the extinction of the Ediacaran animals could have left a pathway for the newly-made Cambrian species. Unfortunately, there are problems that arise when examining this theory. The extinction of the Ediacaran period does not explain the polyphyletic nature or the lengthy duration of the Cambrian Explosion (Xingliang Zhang, 2014). Another theory scholars believe could have led to the rapid appearance of polyphyletic organisms in the Cambrian could have occurred from the mineral and salinity content of the water. The salt concentration that is present in the water controls and limits the amount of biologic activity, since the saltier an area is, the fewer animals can live there. Less animals are able to survive in places that have high salt concentration due to the process of osmosis, which dehydrates the animals making them unable to survive in those environments. From looking at ocean salinity modeling, which was developed by observing maximum and minima values of present day evaporates, scholars have concluded that there was a significant salinity decline from the Neoproterozoic to the Cambrian. The decline in salinity seen in this time period, may have had an
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