<Tr> <Td> Part of a series on </Td> </Tr> <Tr> <Th> Evolutionary biology </Th> </Tr> <Tr> <Td> Diagrammatic representation of the divergence of modern taxonomic groups from their common ancestor </Td> </Tr> <Tr> <Td> Key topics (show) <Ul> <Li> Introduction to evolution </Li> <Li> Common descent </Li> <Li> Evidence of common descent </Li> </Ul> </Td> </Tr>

How many amino acids are common to all living system