What is Cambrian explosion?
What is Cambrian explosion?
It's a period of intense evolution that took place about 500 million years ago, over a period of about 10 million years (give or take a few million), in which most of the major body types ("phyla") we know today evolved. A good overview can be found in Stephen Jay Gould's "Wonderful Life," but be warned that a lot of the taxonomy and other biology in that book is out of touch with current thinking. It's also entirely possible that the Cambrian Explosion wasn't a period of unusually intense evolution, but merely a period in which the already existing diversity of critters developed hard parts that can fossilize.
There are significantly large number of varied explanations for the same
One of the explanation is as follows The "Cambrian Explosion" refers to the sudden appearance in the fossil record of complex animals with mineralized skeletal remains. It may represent the most important evolutionary event in the history of life on Earth.
The beginning of the explosion is generally placed about 542 million years ago, during the Cambrian Period at the start of the Palaeozoic Era (the same time the Ediacarans disappear from the fossil record). While the explosion was rapid in geological terms, it took place over millions of years - the Burgess Shale, at 505 million years old, records the tail end of the event. The explosion is particularly remarkable because all major animal body plans (each more or less corresponding to a distinctive Phylum - Mollusca and Chordata, for example) appeared during this time, changing the biosphere forever.
The rapid appearance of a wide variety of animals - particularly bilaterians - led to the development of radical new ecological interactions such as predation. consequently, ecosystems became much more complex than those of the ediacaran. As the number and variety of organisms increased, they occupied a variety of new marine environments and habitats. Cambrian seas teemed with animals of various sizes, shapes, and ecologies; some lived on or in the sea floor (a benthic lifestyle), while others actively swam in the water column (nektonic).
The fundamental ecological structure of modern marine communities was firmly established during the cambrian. By the end of the period, some animals had also made the first temporary forays onto land, soon to be followed by plants.
There are significantly large number of varied explanations for the same
One of the explanation is as follows
The "Cambrian Explosion" refers to the sudden appearance in the fossil record of complex animals with mineralized skeletal remains. It may represent the most important evolutionary event in the history of life on Earth.
The beginning of the explosion is generally placed about 542 million years ago, during the Cambrian Period at the start of the Palaeozoic Era (the same time the Ediacarans disappear from the fossil record). While the explosion was rapid in geological terms, it took place over millions of years - the Burgess Shale, at 505 million years old, records the tail end of the event. The explosion is particularly remarkable because all major animal body plans (each more or less corresponding to a distinctive Phylum - Mollusca and Chordata, for example) appeared during this time, changing the biosphere forever.
The rapid appearance of a wide variety of animals - particularly bilaterians - led to the development of radical new ecological interactions such as predation. consequently, ecosystems became much more complex than those of the ediacaran. As the number and variety of organisms increased, they occupied a variety of new marine environments and habitats. Cambrian seas teemed with animals of various sizes, shapes, and ecologies; some lived on or in the sea floor (a benthic lifestyle), while others actively swam in the water column (nektonic).
The fundamental ecological structure of modern marine communities was firmly established during the cambrian. By the end of the period, some animals had also made the first temporary forays onto land, soon to be followed by plants.
