A rapid diversification of animal body plans about 540 million years ago.
Over perhaps 13 to 25 million years starting about 540 mya, most major animal phyla appear in the fossil record. Explanations include rising oxygen, ecological arms races, evolution of Hox genes and environmental change. Exceptional sites such as the Burgess Shale preserve soft-bodied animals.
Precambrian Ediacaran fossils and molecular clocks show animals had earlier origins.
A rapid diversification of animal body plans about 540 million years ago.
Cambrian Explosion is one of the 53 topics in Evolution. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Molecular Clock, Evolutionary Developmental Biology, Origin of Life.
The first eyes and hard shells appear.
Work through the Beginner topics in Evolution first, such as Evolution, Natural Selection, Charles Darwin, then return to Cambrian Explosion. Advanced topics assume the Intermediate vocabulary.
The closest topics to Cambrian Explosion are Molecular Clock, Evolutionary Developmental Biology, Origin of Life, Mass Extinctions. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Cambrian Explosion. To practise the whole of Evolution, use the Evolution quiz.
Cambrian Explosion: A rapid diversification of animal body plans about 540 million years ago. Molecular Clock: Uses the steady rate of neutral mutations to estimate when lineages diverged. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Molecular Clock and explain the difference aloud. Finally, take the Evolution quiz and come back to this page for any question you miss.
Uses the steady rate of neutral mutations to estimate when lineages diverged.
🦎 EvolutionStudies how changes in developmental genes, such as Hox genes, produce evolutionary novelty.
🦎 EvolutionHypotheses such as the primordial soup and RNA world explain how self-replicating molecules first arose.
🦎 EvolutionFive major events, including the end-Permian and end-Cretaceous, that wiped out large fractions of species.
🦎 Evolution