The major evolutionary transitions

Szathmary, Eors
Smith, John Maynard

Eors Szathmary is in the Collegium Budapest (Institute for Advanced Study), Szentharomsag u. 2., H-1014 Budapest and Ecological Modelling Research Group, Department of Plant Taxonomy and Ecology, Eotvos University, Ludovika ter 2, H-1083 Budapest, Hungary; John Maynard Smith is at the School of Biological Sciences, The University of Sussex, Brighton BN1 9QG, UK.

Nature 374(6519):p 227-232, March 16, 1995.

There is no theoretical reason to expect evolutionary lineages to increase in complexity with time, and no empirical evidence that they do so. Nevertheless, eukaryotic cells are more complex than prokaryotic ones, 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.