Rise of the Animal Kingdom and Epigenetic Mechanisms of Evolution - Building the Most Complex Structure on Earth - page 246

alleles) is inaccurate. Darwin repeatedly emphasized, especially in the later editions
of The Origin of Species , that the natural selection is aided by:
the inherited effects of the use and disuse of parts; and … by the direct action of
external conditions, and by variations which seem to us in our ignorance to arise
spontaneously. It appears that I formerly underrated the frequency and value of
these latter forms of variation, as leading to permanent modifications of structure
independently of natural selection.
Darwin (1872)
Writing of spontaneous changes, he also pointed out that:
Mere chance … alone would never account for so habitual and large a degree of dif-
ference as that between the species.
Darwin (1872, p. 86)
Natural selection is a force extrinsic to the organism, while the cause of the evo-
lutionary change is internal to the organisms, which is often a response to changes in
environment. Natural selection does not induce changes; it acts on changed individu-
als. In relation to the evolutionary change, natural selection is a post factum action,
while we are interested in the cause and the mechanism of the evolutionary change.
It is a truism to say that evolutionary change emerges before natural selection comes
into play. Indeed, the emergence of the evolutionary change is the raison d'être of nat-
ural selection; there is no need for selection before evolutionary change emerges. This
temporal order shows that natural selection alone cannot be the cause of evolution.
No empirical evidence demonstrates that acquisition of a new gene or a change in
a gene per se , not involving nongenetic factors, produces a morphological novelty.
Or to put it in other words, while it can be demonstrated that new or changed genes
are related to, or even necessary for, evolution of inherited phenotypic changes, there
is no evidence that evolution of a gene would be sufficient for evolving a new phe-
notypic change. Paraphrasing an old adage, genes “can but don't know” how to do
anything. They do not know when, how much, or where in the organism they have
to be expressed. Their expression depends on the flow of epigenetic information.
Regulation of the expression of nonhousekeeping genes in multicellular organisms is
determined by extracellular signals, which in turn represent the terminal elements of
signal cascades or networks. In unicellulars, the control and patterns of gene expres-
sions are determined by extragenomic elements with the cytoskeleton as a central
player (see page 22, The Control System in Unicellulars ).
The paradigm has not made its case on the role of genetic variation (gene muta-
tions and genetic recombination) and changes in allele frequencies in populations as
inducers of evolutionary novelties in animal morphology, behavior, and life histories;
it has not shown in any concrete case, the specific steps through which the genetic
information is embodied in the animal morphology.
Accumulation of a body of challenging evidence from various fields of biologi-
cal study is exposing the inadequacy of the neoDarwinian paradigm to account for
a number of important biological phenomena, such as the sudden emergence of new