Animal Behavior/Speciation

Every individual alive today, the highest as well as the lowest, is derived in an unbroken line from the first and lowest forms - August Frederick Lopold Weismann, German biologist/geneticist (1834–1914)


Taking into consideration the fundamental aspects of biological species, organisms that belong to the same species should interbreed and bring forth a viable offspring. In other words, animals belonging to the same species should give birth to a fertile offspring that can also reproduce. Furthermore, one of the fundamental concepts of understanding speciation is the aspect of postzygotic and prezygotic (König et al., 2019). Essentially, these are the significant barriers that restrain mating in order to bring forth fertile and viable offspring. Taking the aforementioned into consideration, speciation refers to the process of formation of different species. In particular, the process takes place when groups of species develop to diverge and isolated reproductively. There are two significant types of speciation, mainly the sympatric as well as the allopatric speciation.

In particular, the sympatric speciation refers to groups with a standard ancestral population and their evolution progress into a divergent path and culminates into different species without necessarily being in different geographical separation. On the other hand, allopatric speciation refers to species from a standard ancestral population and follows an evolutionary path that is gradually spread as a result of the difference in geographical separation. Despite the comprehensive scholarly work that has focused on speciation, an overall theory of speciation does not exist; however, there are a variety of models that have been gradually developed in order to elucidate the profound role of selection and its culminating favor in specific instances of the evolution of an organism.

In addition to allopatric and sympatric speciation, anagenesis and cladogenesis are additional concepts that are essential to animal behavior and speciation (Vaux, Trewick, & Morgan-Richards, 2016). In particular, agenesis refers to the gradual and developmental evolution that takes place as a result of interbreeding in a particular population. On the contrary, cladogenesis refers to the evolutionary disintegration of a parent species into two dominant distinct species; this process culminates into a clade.


König, K., Zundel, P., Krimmer, E., König, C., Pollmann, M., Gottlieb, Y., & Steidle, J. L. (2019). Reproductive isolation due to prezygotic isolation and postzygotic cytoplasmic incompatibility in parasitoid wasps. Ecology and Evolution, 9(18), 10694-10706.

Vaux, F., Trewick, S. A., & Morgan-Richards, M. (2016). Lineages, splits and divergence challenge whether the terms anagenesis and cladogenesis are necessary. Biological Journal of the Linnean Society, 117(2), 165-176.