Jack Maze, Department of Botany, University of British Columbia, Vancouver, B. C. V6T 1Z4, Canada
Kathleen. A. Robson, Robson Botanical Consultants, 14836 NE 249th Street, Battle Ground, WA 98604, USA
Satindranath Banerjee, Scientificals Consulting, 309-7297 Moffatt Road, Richmond, B. C. V6Y 3E4, Canada
Dedicated to the memory of "Alfie", Alfred B. Acton
?This study attempts to address the relationship between ontogeny and phylogeny by analyzing ovules in two different grasses, Achnatherum nelsonii and A. lettermanii, over four different stages in ovule development. The group analyzed at each time period consisted of the ovules of the two species. We evaluated emergence by calculating the degree of emergence seen in each time period. The degree of emergence is the difference in organization, as expressed by correlation matrices, between lower and higher hierarchical levels. Or, the degree of emergence assesses the amount of within-group variation in organization, the result of diverging developmental trajectories. We incorporated time into this study through the different developmental stages that reflect ontogenetic time and the two species that represent phylogenetic time. The degree of emergence increased over the last two developmental stages. Both ontogeny and phylogeny can be viewed as events wherein matter is transformed as energy moves from one state to another, as energy is transformed into information. The expression taken by this information will be determined by the plant in which it occurs as the cytoplasm of the developing organism elicits certain responses from the code stored in the DNA. The changes that occur during ontogeny and phylogeny result from variation in the transformation of energy to information within plants, local scale ontogeny, or among groups of related plants, global level phylogeny.