Abstract
Examples from various plant and animal groups indicate that there has been a general increase in potential versatility of form, determined by the number and range of independently varying morphogenetic parameters, among taxa appearing at successively younger stages in the fossil record. Taxa or body plans with higher potential versatility have tended to replace less potentially versatile groups in the same or similar adaptive zone through time. Greater potential diversity allows for greater homeostasis, efficiency, and integration of structures and functions, and for an increase in size of the potential adaptive zone. In contrast, chemical versatility has generally decreased within groups from the pre-Cambrian to the Phanerozoic, partly as the result of apparent changes in the chemical environment and partly as the consequence of selection for efficiency and greater metabolic ease of handling of certain materials.
Keywords: evolution, fossils, morphology, higher taxa
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Selected References
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- Brock T. D. Lower pH limit for the existence of blue-green algae: evolutionary and ecological implications. Science. 1973 Feb 2;179(4072):480–483. doi: 10.1126/science.179.4072.480. [DOI] [PubMed] [Google Scholar]
- SIMPSON G. G. The nature and origin of supraspecific taxa. Cold Spring Harb Symp Quant Biol. 1959;24:255–271. doi: 10.1101/sqb.1959.024.01.025. [DOI] [PubMed] [Google Scholar]
- Schaeffer B. The role of experimentation in the origin of higher levels of organization. Syst Zool. 1965 Dec;14(4):318–336. [PubMed] [Google Scholar]
- Shapiro J. Blue-green algae: why they become dominant. Science. 1973 Jan 26;179(4071):382–384. doi: 10.1126/science.179.4071.382. [DOI] [PubMed] [Google Scholar]
- Thomson K. S. The biology of the lobe-finned fishes. Biol Rev Camb Philos Soc. 1969 Feb;44(1):91–154. doi: 10.1111/j.1469-185x.1969.tb00823.x. [DOI] [PubMed] [Google Scholar]