∞ generated and posted on 2016.11.04 ∞
Divergence in the properties of two or more species following separation of their gene pools and in the course of speciation and extinction events.
Comparisons between species can be made in terms of morphology, physiology, behavior or, as is increasingly the case, in terms of base sequences. A basic assumption is typically made that the more similar two species, in terms of what are known as homologous characters, then the more recent the speciation event that separated the two lineages.
Macroevolution typically is presented as contrasting microevolutionary processes. In many ways, however, macroevolution and microevolution simply represent different perspectives on the same evolutionary processes.
Macroevolution also considers the impact of differential rates of species formation (particularly cladogenesis) and extinction. Those species that give rise to new species at faster rates and/or which that tend to resist extinction more effectively will be the most represented among species, a concept known as species selection.
The following video depicst an animated series of fossil reconstructions illustrating the progression of whale evolution: