The Cambrian explosion is referred to as “Biological Big Bang” (Science News) or “Evolution’s Big Bang” (Science) (Levinton, J. S.1992), because of the unexpectedness presence of animal life in the Cambrian. Figures have it that it started back 542 million years ago and terminated approximately 40 million years later. This era is marked by the emerging of profuse skeletonized metazoans, an abrupt intensification in biodiversity and the appearance of most modern lives (Von Bloh 18). Animals that appeared suddenly in this era include: hard bodied brachiopods, those with dorsal nerve cord, and the arthropods. During the explosion, an approximate number of about thirty-five, of the total forty phyla appeared on the earth’s surface. Phyla are known
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Evidences which can explain this include: oxygen, environmental, glaciation, and developmental explanations. For oxygen explanation, it is known that the metabolism of all multicellular creatures function with help of oxygen. When the O2 level is down the metabolism rate is low, and in its absence, no animal can live. It is possible that photosynthesis could have triggered a rise in oxygen in the atmosphere and the oceans at the start of the Cambrian, thus permitting a huge evolution of complex animals which possessed circulatory and respiratory mechanisms. It is possible that increased levels of oxygen sped up large Ediacaran metazoans before the explosion. Environmental explanations reveal that prior to evolution of complex animals on earth, there must have been an ideal environment to support their survival. The strongest of all the favorable environmental conditions for the evolution that scientist have identified is the high rate of oxygen when the glacial period ended. Glaciation is another environmental justification of the explosion happening. "Snowball Earth" hypothesis states that before the Cambrian explosion, the whole universe was covered with ice. Glaciers restricted evolution functions in the sea, like blocking rays of the sun from penetrating the waters yet algae and cyanobacterial mats rely on it. When retreatment of glaciers happened, a change of life was earned for many organisms. Particulary, the post post-glacial period proved vital for evolution, as it is said that huge complex multicellular organisms appeared when the temperatures were rising proving that the environment was favorable for evolution. As for the developmental evidence, scientists say that the environment never had nothing unique during the Precambrian-Cambrian transition, and it was a necessity for evolution to happen for diverse and new body plans to emerge. In animals, developmental genes are the ones responsible in
Evidences which can explain this include: oxygen, environmental, glaciation, and developmental explanations. For oxygen explanation, it is known that the metabolism of all multicellular creatures function with help of oxygen. When the O2 level is down the metabolism rate is low, and in its absence, no animal can live. It is possible that photosynthesis could have triggered a rise in oxygen in the atmosphere and the oceans at the start of the Cambrian, thus permitting a huge evolution of complex animals which possessed circulatory and respiratory mechanisms. It is possible that increased levels of oxygen sped up large Ediacaran metazoans before the explosion. Environmental explanations reveal that prior to evolution of complex animals on earth, there must have been an ideal environment to support their survival. The strongest of all the favorable environmental conditions for the evolution that scientist have identified is the high rate of oxygen when the glacial period ended. Glaciation is another environmental justification of the explosion happening. "Snowball Earth" hypothesis states that before the Cambrian explosion, the whole universe was covered with ice. Glaciers restricted evolution functions in the sea, like blocking rays of the sun from penetrating the waters yet algae and cyanobacterial mats rely on it. When retreatment of glaciers happened, a change of life was earned for many organisms. Particulary, the post post-glacial period proved vital for evolution, as it is said that huge complex multicellular organisms appeared when the temperatures were rising proving that the environment was favorable for evolution. As for the developmental evidence, scientists say that the environment never had nothing unique during the Precambrian-Cambrian transition, and it was a necessity for evolution to happen for diverse and new body plans to emerge. In animals, developmental genes are the ones responsible in