David Bourget (Western Ontario)
David Chalmers (ANU, NYU)
Rafael De Clercq
Jack Alan Reynolds
Learn more about PhilPapers
Acta Biotheoretica 38 (2):113-124 (1990)
Phytomorphology — if concerned with development — often concentrates on correlative changes of form and neglects the aspects of age, time and clock, although the plant's spatial and temporal organisation are intimately interconnected. Common age as measured in physical time by a physical process is compared to biological age as measured by a biological clock based on a biological process. A typical example for a biological clock on the organ level is, for example, a shoot. Its biological age is measured by the biological time unit of a plastochron, which itself is defined by the cyclic-periodic initiation of the leaves. In a controlled environment biological age may replace physical age. However, biological and physical age are not necessarily linearly convertible into each other. In stationary or steady state conditions the repetitive initiation of any organ, unit or module of an articulate plant or plant modular system may define the biological time unit. A linear — monotonous biological process, e.g. axis elongation, may also define a biological time unit as a certain amount of additional growth, e.g. of length. One may speak of periodical and of continuous plastochron or, perhaps, of plastochron and rheochron. A precise measure of biological age is the generalized plastochron index applying to any modular system and module respectively. However, one should be aware that it is based on two clocks, one of them referring to the periodic process of module initiation for counting the integer plastochrons and the other to the continuous plastochron of module growth for the determination of the fraction of one plastochron. The application of the concepts is restricted to phases of stationary or steady state growth and development. In certain cases of non-stationary or non-steady state conditions a normalized-age concept may apply.
|Keywords||No keywords specified (fix it)|
|Categories||categorize this paper)|
Setup an account with your affiliations in order to access resources via your University's proxy server
Configure custom proxy (use this if your affiliation does not provide a proxy)
|Through your library|
References found in this work BETA
No references found.
Citations of this work BETA
No citations found.
Similar books and articles
Adolph Portmann (1990). On the Uniqueness of Biological Research. Journal of Medicine and Philosophy 15 (5):457-472.
Daniel R. Brooks, John Collier, Brian A. Maurer, Jonathan D. H. Smith & E. O. Wiley (1989). Entropy and Information in Evolving Biological Systems. Biology and Philosophy 4 (4):407-432.
Susan C. Johnson (1998). Folk Taxonomies and Folk Theories: The Case of Williams Syndrome. Behavioral and Brain Sciences 21 (4):578-579.
Titus R. Neumann, Susanne Huber & Heinrich H. Bülthoff (2001). Artificial Systems as Models in Biological Cybernetics. Behavioral and Brain Sciences 24 (6):1071-1072.
Robert Wachbroit (1994). Normality as a Biological Concept. Philosophy of Science 61 (4):579-591.
Benoni B. Edin (2008). Assigning Biological Functions: Making Sense of Causal Chains. Synthese 161 (2):203 - 218.
A. T. Nuyen (2007). Confucian Ethics and "the Age of Biological Control". Philosophy East and West 57 (1):83-96.
Jacques Demongeot (2009). Biological Boundaries and Biological Age. Acta Biotheoretica 57 (4):397-418.
Added to index2009-01-28
Total downloads7 ( #304,000 of 1,726,237 )
Recent downloads (6 months)2 ( #289,836 of 1,726,237 )
How can I increase my downloads?