Evolution and its theories

Already in Ancient Greece men pondered on the idea of evolution by questioning the origins of the human species (National Geographic). The ancient philosopher Anaximader reflected on the idea of evolution by observing human beings which, helpless at birth, must have originally derived from a more self sufficient species able to survive with no help  since childhood, such as fishes (National Geographic).

However, the most scientific idea of theory of evolution came only much later with Charles Darwin and Alfred Russel Wallace in 1859 (National Geographic). This because of the intrinsic definition of "theory" which can be used to describe a scientific explanation only after rigorous testing through observations and experiments (National Geographic). 

The idea behind this theory is that evolution occurs by natural selection, where the "fittest" that survive the environmental changes are those which traits are more prompt to such conditions (Darwin 1859).

Nowadays, research regarding speciation evolved into several theories and hypothesis, most specifically the focus has switches more and more towards genomic approaches to species diversifications, called speciation genomics (Seehausen 2014). This integration of evolutionary theory with genomics will "help to elucidate the relationships between evolutionary processes and genomic divergence patterns on the one hand and between genomic properties and speciation processes on the other hand" (Seehausen 2014). Speciation itself originates when populations are faced with reproductive barriers which result in genetic and phenotypic distinctiveness of organisms in geographical proximity (Seehausen 2014). As a consequence, reproductive barriers can be an outcome of divergent selection, i.e. extrinsic reproductive isolation, or by evolution, i.e. intrinsic reproductive isolation which is a result of genomic conflict (Seehausen 2014). Earl and Deem with their publication in 2004 regarding evolvability take the genomic variable of evolution to the next level (Earl 2004). It has been always generally acknowledged that adaptation through natural selection occurs within the constraints set by a particular genetic system, however it becomes now an inquiry whether genomics themselves have the ability to evolve  (Earl 2004).

In conclusion, the theories and implications of evolutionary designs are still a highly researched field which will benefit increasingly more by the recent developments in computational computers unlocking the ability to assess high volumes of data with accurate probabilities (Bell 2005). Specific investigation into genomic base of speciation will allow us to unravel more precise the patterns of species diversity not only dependant on ecological isolation (Seehausen 2014). 



References:

Darwin, Charles, (1859), On the origin of species by means of natural selection, or preservation of favoured races in the struggle for life 


Theory of Evolution, National Geographic, Available at: https://education.nationalgeographic.org/resource/theory-evolution/


Ole Seehausen, et al, (2014), Genomics and the origin of species, Nature Reviews Genetics 15(3)


Earl, David J, (2004). Evolvability is a selectable trait, Proceedings of the National Academy of Sciences - PNAS, 101 (32)


Bell, G., (2005), The evolution of evolution, Heredity 94(1-2)

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