Frozen Evolution. Or, that’s not the way it is, Mr. Darwin. A Farewell to Selfish Gene.

Ecological theories of sexual reproduction assume that sexuality is advantageous in
certain conditions, for example, in biotically or abiotically more heterogeneous environments.
Such theories thus could be tested by comparative studies. However, the
published results of these studies are rather unconvincing. Here, we present the results
of a new comparative study based exclusively on the ancient asexual clades. The
association with biotically or abiotically homogeneous environments in these asexual
clades was compared with the same association in their sister, or closely related, sexual
clades. Using the conservative definition of ancient asexuals (i.e., age >1 million
years), we found eight pairs of taxa of sexual and asexual species, six differing in the
heterogeneity of their inhabited environment on the basis of available data. The difference
between the environmental type associated with the sexual and asexual species
was then compared in an exact binomial test. The results showed that the majority of
ancient asexual clades tend to be associated with biotically, abiotically, or both biotically
and abiotically more homogeneous environments than their sexual controls. In
the exploratory part of the study, we found that the ancient asexuals often have durable
resting stages, enabling life in subjectively homogeneous environments, live in the
absence of intense biotic interactions, and are very often sedentary, inhabiting benthos,
and soil. The consequences of these findings for the ecological theories of sexual
reproduction are discussed.

Natural selection is considered to be the main process that drives biological evolution. It requires selected
entities to originate dependently upon one another by the means of reproduction or copying, and for the
progeny to inherit the qualities of their ancestors. However, natural selection is a manifestation of a more
general persistence principle, whose temporal consequences we propose to name “stability-based sorting”
(SBS). Sorting based on static stability, i.e., SBS in its strict sense and usual conception favors characters
that increase the persistence of their holders and act on all material and immaterial entities. Sorted entities
could originate independently from each other, are not required to propagate and need not exhibit
heredity. Natural selection is a specific form of SBS—sorting based on dynamic stability. It requires some
form of heredity and is based on competition for the largest difference between the speed of generating
its own copies and their expiration. SBS in its strict sense and selection thus have markedly different
evolutionary consequences that are stressed in this paper. In contrast to selection, which is opportunistic,
SBS is able to accumulate even momentarily detrimental characters that are advantageous for the long-term
persistence of sorted entities. However, it lacks the amplification effect based on the preferential
propagation of holders of advantageous characters. Thus, it works slower than selection and normally is
unable to create complex adaptations. From a long-term perspective, SBS is a decisive force in evolution—
especially macroevolution. SBS offers a new explanation for numerous evolutionary phenomena, including
broad distribution and persistence of sexuality, altruistic behavior, horizontal gene transfer, patterns of
evolutionary stasis, planetary homeostasis, increasing ecosystem resistance to disturbances, and the universal
decline of disparity in the evolution of metazoan lineages. SBS acts on all levels in all biotic and
abiotic systems. It could be the only truly universal evolutionary process, and an explanatory framework
based on SBS could provide new insight into the evolution of complex abiotic and biotic systems

Punctuational theories of evolution suggest that adaptive evolution proceeds mostly, or even entirely, in the distinct periods of existence of a particular species. The mechanisms of this punctuated nature of evolution suggested by the various theories differ. Therefore the predictions of particular theories concerning various evolutionary phenomena also differ.
Punctuational theories can be subdivided into five classes, which differ in their mechanism and their evolutionary and ecological implications. For example, the transilience model of Templeton (class III), genetic revolution model of Mayr (class IV) or the frozen plasticity theory of Flegr (class V), suggests that adaptive evolution in sexual species is operative shortly after the emergence of a species by peripatric speciation – while it is evolutionary plastic. To a major degree, i.e. throughout 98-99% of their existence, sexual species are evolutionarily frozen (class III) or elastic (class IV and V) on a microevolutionary time scale and evolutionarily frozen on a macroevolutionary time scale and can only wait for extinction, or the highly improbable return of a population segment to the plastic state due to peripatric speciation.
The punctuational theories have many evolutionary and ecological implications. Most of these predictions could be tested empirically, and should be analyzed in greater depth theoretically. The punctuational theories offer many new predictions that need to be tested, but also provide explanations for a much broader spectrum of known biological phenomena than classical gradualistic evolutionary theories.
This article was reviewed by Claus Wilke, Pierre Pantarotti and David Penny (nominated by Anthony Poole).