THE MAJOR EVOLUTIONARY TRANSITIONS

There is no theoretical reason to expect evolutionary lineages to incr ease in complexity with time, and no empirical evidence that they do s o. Nevertheless, eukaryotic cells are more complex than prokaryotic on es, animals and plants are more complex than protists, and so on. This increase in complexity may have been achieved as a result of a series of major evolutionary transitions. These involved changes in the way information is stored and transmitted.