What is the Cambrian explosion Was it really explosive Is so

What is the Cambrian explosion? Was it really explosive? Is so, in what way; if not, how would you justify your answer?

What is a molecular clock? What are its assumptions? How can it be used to date the origins of animal diversification? How do these results compare with what we see in the fossil record? Explain.

How do explanations invoking “Genetic toolkit” versus “environmental factors” relate to the idea of intrinsic versus extrinsic explanations of diversification?

Solution

The cambrian e xplosion was not an explosion. Rather it was an evolutionary event in the cambrian period, around 541 million years ago, when the evolution of animal phyla took place.

It was a divergence evolution and led to tue appearance of metazoan phyla and djversification of many other organisms. Before cambrian explosion, organisms used to live in colonies and this evolutionary event led to monophyletic evolution of multicellular organisms.

MOLECULAR CLOCK

this is a technique to deduce the hostoric time when two forms of life diverged.

Mutation rate are identified with the gkssil record if DNA RNA and amino acids. It is also called genetic clock. Molecular clock is also useful in molecular systemics.