References: 1) Bortz, W. Exercise as an Evolutionary Force.
Any force causing such changes, including artificial selection, is an evolutionary force.
In our interpretation, the walker tends to the maximal free fitness state, driven by the evolutionary force X.
Introducing the 'free fitness' as the sum of a fitness term and an entropy term and 'evolutionary force' as the gradient of free fitness on a fitness coordinate, we demonstrated that the adaptive walk (=evolution) is driven by the evolutionary force in the direction in which free fitness increases.
Hybridisation is presumed to be an important mechanism in plant speciation and a creative evolutionary force often accompanied by polyploidisation and in some cases by apomixis.
Hence, an alternative explanation is that morphs are under NFDS, a powerful evolutionary force maintaining polymorphism (by favouring rare morphs, including in lizards e.g. Uta stansburiana, [ 20]; Anolis sagrei, [ 9]), thus countering the influence that local environmental conditions may have on morph frequencies.
Such post-copulatory sexual selection can be a potent evolutionary force, as is evidenced by the numerous male behavioral, physiological, and morphological adaptations that influence sperm competition, such as mate guarding, increased copulation duration, seminal fluid induced reluctance of female re-mating, and the mechanical removal of sperm [ 1- 3].
Yet there's a greater evolutionary force behind this.
Evolutionary biologists have come to recognize humans as a tremendous evolutionary force.
WGD is a major evolutionary force in angiosperm genomes.
