Smith, Maynard

Maynard-Smith, J. and Harper, D. 2003. Animal Signals. Oxford University Press, Oxford. 

Maynard Smith, J. (1998), Shaping Life Genes, Embryos and Evolution, Yale University Press, New Haven, CT. 

In the last 20 years, a new problem, the evolutionary origin of levels of organization, or evolutionary transition, has been added to those celebrated since Darwin (Buss, 1987). In their recent book, The Major Transitions in Evolution, Maynard Smith and Szathmary (1995, p. 6) identified what they considered to be eight major originations of new levels of organization (Table 11.1). For most of these, they claimed a common feature . .. entities that were capable of independent replication before the transition... 

TABLE 11.1 The major transitions and levels in evolution (al ter Maynard Smith and Szathmary, 1995)... 

Notice that the common feature of many evolutionary transitions identified by Maynard Smith and Szathmary involves a change in the status of replicators. Once the replication of a class of entities becomes dependent on a larger whole, they do not become independent replicators again. So new replicators at the emergent level must exist and replicate independently in order for there to be a still higher level transition. Given the nature of replicators as analyzed by both Dawkins and Hull, there is a problem with this characterization of the common feature only one or possibly two evolutionary transitions are at all likely to have occurred in the history of life. 

Maynard Smith, J. and SzathmaryJ. (1995), The Major Transitions in Evolution, W. H. Freeman, Oxford, UK. 

Maynard Smith, J. (1982), Evolution and the Theory of Games, Cambridge University Press, Cambridge, UK. 

Maynard Smith, J. and Szathmary, E. (1998). The Origins of Life. Oxford University Press, Oxford. Morowitz, H. (2002). The Emergence of Everything. Oxford University Press Inc., New York. Mulkidjanian, A.Y., and Junge, W. (1999). Primordial UV-protectors as ancestors of the photosynthetic pigment protein. In G. A. Peshek, et al. (eds). The Phototropic Prokaryotes. Kluwer Academic Press Pub., New York, pp. 805-812... 

Magnusson, 190a, 195a, 211a Malinowski, 216 Mallick, 37 Manning, 179 Markl, 92 Markov, 102 Marler, 10 Marshall, 169 Martin, 132—133 Masters, 16, 30 Masutani, 30, 31 Matheson, 53 Mattei-Muller, 15 Maynard Smith, 66, 68, 73 Mazur, 11 McCall, 131 McCandless, 37 McClearn, 128-129, 136 McCoy, 146... 

Figure 7.4 Schemae of the formose reaction (a) spontaneous, slow formation of glycolaldehyde from formaldehyde (b) after one cycle, one new molecule of glycolaldehyde is produced. The structural isomers of sugars are specified by the carbon skeleton and by the position of the carbonyl group (open circle). (Adapted, with some modifications, from Maynard Smith and SzathmSry, 1995.)...

Figure 7.12 A simple rendering of an hypercycle. Each of the units A, B, C and D is a replicator. The rate of replication of each unit is an increasing function of the concentration of the unit immediately proceeding it. Thus the rate of replication of B is an increasing function of the concentration of A, and so on round the cycle. (Adapted from Maynard-Smith and Szathmary, 1995.)...

Figure 8.10 Ganti s chemoton (redrawn from Maynard-Smith and Szathmary, 1995, based on the original by Ganti, 1984). The metabolic subsystem, with intermediates Ai -> A2 ->. . . A5, is an autocatalytic chemical cycle, consuming X as nutrient and producing Y as waste material pV is a polymer of n molecules of V which undergoes template replication R is a condensation byproduct of this replication, needed to turn into T, the membranogenic molecule the symbol Tm represents a bilayer membrane composed of m units made of T molecules.

Maynard-Smith and Szathmary (1995) discuss at length some of the implications of the chemoton, for example, the question of how the chemoton has heredity. They point out some of the difficulties in implementing the chemoton but conclude by saying (Maynard Smith and Szathmary, 1995) ... 

Evolutionary algorithms are frequently used to find optimal solutions in many different problem areas. They are based on Darwin s principle of survival of the fittest (Darwin 1996 Maynard Smith 1993). A population of individuals has to compete with other individuals for access to food and mates. Only the successful ones are allowed to reproduce. This leads to the reproduction of certain inheritable traits into the next generation. 

CG Dowson, A Hutchison, JA Brannigan, RC George, D Hansman, J Linares, A Tomasz, J Maynard-Smith, BG Spratt. Horizontal transfer of penicillin-binding protein genes in penicillin-resistant clinical isolates of Streptococcus pneumoniae. Proc Natl Acad Sci (USA) 86 8842-8846, 1989. 

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