What did cause the Cambrian Explosion?

[MaxCathedral]

What did cause the Cambrian explosion?

[Mokele]

We aren't sure, and there are many competing theories. However, the most popular and supported one currently is that entire clusters of genes governing embryonic development were duplicated (these duplications happen commonly), possibly several times, allowing animal life to undergo more complex embryonic development, which in turn resulted in the diversity of forms.

 

Mokele

[Halucigenia]

I just have to respond to this one, given my avatar.

I would explain the Cambrian explosion by suggesting that up until this point in time the evolution of organisms had not proceeded to sufficient complexity to be able to exploit all the niches available, at least within the oceans, so that when the mechanism of complex embryonic development that Mokele described did happen, then there was little competition, so the multitude of different types of organisms could thrive and exploit the available ecology, which in turn was created by this biodiversity.

Sorry about the long sentence but it just flowed out like that.

[cambrian_exp]

during cambrian explosion basic body plans of multicellular life on earth were established... then why didnt it happened again in earth's history. i mean why did no new phylum emerged after cambrian explosion?

[Mokele]

Body plans do not equate to phyla. For instance, the vertebrate body place has been modified many times since the cambrian, such as the addition of jaws and limbs. Arthropod body plans have similarly diversified. Alternatively, most worms have the same basic bodyplan, but are divided into multiple phyla.

 

However, the problem is that in modern times, with so many ecological niches filled, major new body plans offer comparatively little advantage, since they'd be put into competetion with older, established plans.

 

Innovation is always harder than just modifying existing infrastructures. In biology, that means it will be a comparative rarity.

 

Mokele

[gmacrider]

I just have to respond to this one' date=' given my avatar.

I would explain the Cambrian explosion by suggesting that up until this point in time the evolution of organisms had not proceeded to sufficient complexity to be able to exploit all the niches available, at least within the oceans, so that when the mechanism of complex embryonic development that Mokele described did happen, then there was little competition, so the multitude of different types of organisms could thrive and exploit the available ecology, which in turn was created by this biodiversity.

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So when the explosion filled all the niches, the serious competition became global and the opportunities and niches for new phyla disappeared?

[Paramecium]

Theres a fact, that before cambrian explosion all (or majority, simply this trend wasnt invented yet) animals didnt have exo or endosceleton so there is very poor record of fossils which have stayed preserved(and thus we are not so sure about richnes of life of these times). Also the exo and endosceleton is a one of the major causes which could participated to cambrian explosion.