What is the Cambrian Explosion?
Also called the Cambrian Radiation, it was an event that happened roughly 541 million years ago where almost all major animal phyla began to appear in the fossil records. The event lasted for about 13 to 25 million years and resulted in the divergence of most animal phyla. Life became much more complex, and the oceans filled with a stunning level of diversity. Prior to this event, organisms were rather simple, with unicellular life dominating the landscape.
Life After the Cambrian Explosion
The Cambrian Explosion gave way to a world filled with complex lifeforms with anatomical features that we see in modern animals. One of the most prominent groups to evolve during this event was the arthropods. These animals had legs, compound eyes and appendages that could help catch prey. Many members even evolved chitinous shells that acted as armour plating against predators.
What Caused The Cambrian Explosion?
Some scientists speculate that a steep rise in oxygen levels acted as a trigger. Others speculate that the evolution of certain biological innovations and mechanisms, such as eyes, caused the explosion. A few others theorize that the formation of the Earth’s ozone layer provided shielding against the DNA-damaging UV rays, triggering the explosion of complex lifeforms. Other explanations include the arms race, a kind of struggle between predator and prey, co-evolving traits, genes or species that adapt and counter-adapt against each other. Even a mass extinction has been proposed as the cause of the explosion, as existing clades expanded to occupy eco spaces left behind by the extinction. However, the actual reason still remains elusive as little is known about the chemical and physical environment during that time period.
Organisms of The Cambrian Explosion
Following are notable organisms that rose after this event:
- Anomalocaris
- Pikaia
- Haikouichythes
- Wiwaxia
- Spriggina
Frequently Asked Questions on Cambrian Explosion
1. What is the Cambrian Explosion
The cambrian explosion was an event that happened roughly 541 million years ago where almost all major animal phyla began to appear in the fossil records. The event lasted for about 13 to 25 million years and resulted in the divergence of most animal phyla.
2. What Caused The Cambrian Explosion?
Many theories have been put forth to explain the event:
- A steep rise in oxygen levels acted as a trigger
- The evolution of certain evolutionary innovations may have triggered an explosion.
- The formation of the Earth’s ozone layer may have provided a safe environment, triggering the explosion of complex lifeforms.
- An arms race may also have been a contributing factor.
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