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

Intraspecific competition is based on competition between the individual alleles for the greatest frequency in the gene pool of future generations.In contrast, species and, fundamentally, also higher taxa compete primarily in the numbers of new species that they split off during their existence.The phylogenetic lines that contain species that most frequently undergo speciation and later become extinct have a chance during evolution to force out phylogenetic lines that have lower values of these parameters, regardless of how direct ecological competition between the members of the participating species would turn out.Competition between phylogenetic lines for the rate of speciation and extinction, to be more exact, for the greatest ratio between these two rates, is termed species selection.

            The effect of species selection on anagenetic processes was discussed in Section IV.8.4.From the viewpoint of cladogenesis and especially from the aspect of the entire history of organisms on the Earth, it is important that species selection can apparently cause the extinction of a certain phylogenetic line even under conditions where the individual species forming this line are just as well adapted to their environment as their competitors in another taxon.

            The reason why continuous, long-term action of species selection did not lead to the formation of complex traits that would increase the probability of speciation and reduce the probability of extinction, i.e. similar to the adaptive traits increasing the fitness of an individual, consists in the fact that most traits that increase the probability of speciation simultaneously necessarily increase the probability of extinction.For example, a sessile life style in small populations increases the probability of speciation, but simultaneously increases the probability of extinction as a consequence of local disturbances (destruction or drastic changes) in the environment.A species forming a large population is more resistant to extinction as a consequence of a local disturbance, but its potential for speciation is smaller than in a species with less numerous populations.This is true, at the very least, because more effective stabilizing selection makes it harder to overcome the valleys in the adaptive landscape.

            However, it cannot be excluded that, at the very least, two very important complex traits that are useful from the aspect of species selection have emerged during evolution as a consequence of species selection.The first of these could be the capacity for active flight, which enables species to stay in locally numerous flocks and move on a global scale as local conditions change.The numbers of species of bats, birds and, in fact, also fish, is much greater than amongst their non-flying (for fish, non-“flying”) relatives {14400}.The second complex trait could be sexual reproduction, which is accompanied by some very effective mechanisms of species cohesion, enabling the emergence and existence of distinct species.If sexual reproduction in nature has actually predominated as a consequence of species selection, it is not surprising that all attempts to explain the existence and predominance of sexual reproduction in terms of natural selection seem rather unsuccessful.