Две теории биологической эволюции. Гродницкий Д.Л. - 130 стр.

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obtained by Shaposhnikov (1966). In his experiment, the aphid Dysaphis anthrisci
majcopica Shap. adapted to feeding on a novel host plant, Chaerophyllum macula
tum, and became reproductively isolated from its parental population. At the same
time, these aphids morphologically converged to and started to cross with D. chaero
phyllina Shap. — a species normally feeding on C. maculatum. Thus, not a new but
a previously existing species was generated.
Summarizing, a number of well established facts contradict conclusions derived
from the synthetic evolutionary theory. How could we improve the situation? Two
methods are thinkable to remove the existing contradiction between the theory and
observations. First, we can hope the inconsistencies are owing to a shortage of our
knowledge of the organisms. Thus, future research in population genetics will hope
fully explain why complex beings evolve faster than simpler ones, as well as resolve all
other above stated queries. The second method implies creation of a new theory. To
be on the safe side, both methods should be tried.
What kind of a theory can be suggested? The answer is offered by neo
Darwinians who ascribe the constancy of living forms by developmental and morpho
functional constraints on evolutionary change (Lande 1980; Charlesworth et al.
1982). The idea of constraints looks very natural: an organism can be transformed
only by means of a strongly restricted number of methods determined by morpholo
gy and ontogeny of the organism (Wake 1982; Roth & Wake 1985). Deviations from
an appearance typical of a given taxon disturb adult and/or embryonic functions and
thereby are prohibited by natural selection. Owing to multiple limitations, living
beings are similar in mathematic sense: their morphologic and physiologic parame
ters obey certain allometric regularities that have been described in a plenty of litera
ture sources, beginning from the monographs of Huxley (1932) and D’Arcy
Thompson (1942).
The constraint concept is attractive. It explains in a believable manner the mor
phologic stasis and the absense of evolution under strict isolation and abrupt popula
tion fluctuations, the paraphyletic (repeating) taxa origins, and even the acceleration
of evolution at the increase of organismal complexity. However, if these explanations
are true, an adequate evolutionary theory must be expressed in terms of organismal
morphology and development, whereas the synthetic theory considers morphology
generating mechanisms as just constraints, i. e. as something foreign. Indeed, real
organisms are more than just «the vehicles for genes» (Goodwin 1997): their partic
ular morphologies are largely determined by reasons other than genome composition.
Hence, evolution can be more than just allelic substitution. Thus, whenever we con
sider evolution as the historic change of organismal morphology, we would need an
«organismocentric» rather than «genocentric» approach (Goodwin 1997).
Fundamentals of an organismcentered evolutionary paradigm were formu
lated by Mikhail A. Shishkin (1984, 1987, 1988) who put forward a view on evolu
tion as a process of transformation of ontogenies, first formulated by Conrad
Waddington (1940, 1957, 1975) and Ivan Schmalhausen (1949). One of the prin
cipal properties of phenotypes is their resistance to changes occurring both in envi
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