Expanding the View of Emergence in Individuals, Populations, and Species of Stipoid Grasses: A Comparison Including Achnatherum occidentale


Jack Maze, Professor Emeritus

Department of Botany

 University of British Columbia

Vancouver, B. C. V6T 1Z4, Canada

E-mail: jmaze@interchange.ubc.ca


Kathleen. A. Robson

 Robson Botanical Consultants

306 Wyman Road

Woodland, WA 98674, U. S. A.

E-mail: nwplants@teleport.com


Satindranath Banerjee

Scientificals Consulting

309-7297 Moffatt Road

Richmond, B. C., V6Y 3E4 Canada

E-mail: mishtu_banerjee@telus.net


Dedicated to the memory of Mareen S. Kruckeberg, friend to people and plants.

© This paper is not for reproduction, quotation, or citation without the express
 permission of the authors.


In our ongoing studies of emergent properties at different hierarchical levels in the grass tribe Stipeae, an additional species, Achnatherum occidentale, is included to broaden the comparison. The degree of emergence seen parallels that of previous studies, an increasing trend from populations to individuals and species to related groups of species. The degree of emergence in species pairs that hybridize, A. hendersonii and A. lemmonii, or A. occidentale and A. lemmonii, is lower than in non-hybridizing species pairs of Achnatherum, including the closely related pair of A. wallowaensis and A. hendersonii. The degree of emergence assesses the relationship among variables. This relationship, in turn, is the end product of integrated developmental pathways; a lower degree of emergence reveals similar responses among developmental pathways. Similar developmental responses may facilitate hybridization since hybrid survival requires coordinated development. The different developmental pathways inferred for A. hendersonii and A. wallowaensis argue for the existence of different developmental ways to very similar ends, the spikelets in the two species. The outcome of speciation, as viewed from a developmental perspective, seems best accounted for through theories that relate the dissipation of energy to the transformation of matter along with conceptualizing a species as a virtual code that achieves material expression only when an individual appears. This view of a species is explored through structural relationships within and among grass species.

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