Question

What four major advances in life on Earth took place during the Cambrian explosion?

Answer 1

Solution:

​​​​​​The Cambrian Explosion refers to the sudden appearance in the fossil record of complex animals with mineralized skeletal remains. It represents the most important evolutionary event in the history of life on the Earth.

The beginning of the Cambrian Explosion generally placed about 542 million years ago, during the Cambrian Period at the start of the Palaeozoic Era.

The major advances on Earth that took place during the Cambrian Explosion are:

1) The Cambrian Explosion resulted in the divergence of most modern metazoan phyla. The event was accompanied by major diversification of other organisms.  The explosion is particularly remarkable because all major animal body plans (each more or less corresponding to a distinctive Phylum - Mollusca and Chordata) appeared during this time, which changed the biosphere forever.

2) Due to the Cambrian Explosion, the rapid appearance of a wide variety of animals, particularly bilaterians occured, which led to the development of new ecological interactions such as predation. Consequently, ecosystems became much more complex. As the number and variety of organisms increased, they occupied a variety of new marine environments and habitats. So, The fundamental ecological structure of modern marine communities was established.

3) The early record of the Cambrian Explosion is based on fossils record, mainly the appearance of mineralized skeletons and fossil traces. About 521 million years ago, trilobites made their first appearance in the Cambrian fossil record. Trilobites eventually became one of the most ubiquitous groups of invertebrate in the Palaeozoic seas. There fossils can be found from the Cambrian periods due to Cambrian Explosion.

4) Some well-preserved soft-bodied fossils of Cambrian age were first described from the Burgess Shale over 100 years ago. Nowadays, dozens of Burgess Shale-type deposits with assemblages of fossils have been found. These deposits are characterized by a similar mode of preservation called "Burgess Shale-type preservation" and these have occured during Cambrian Explosion.