Desmistificando a raridade da formação de híbridos férteis em animais

Abstract

The emergence and formation of species is an area of ​​great interest in the scientific knowledge of genetics, conservation biology and evolution. One of the most validated conceptions in relation to the formation of species is the factor of isolation barriers, in which populations that mate naturally with each other are reproductively isolated from other groups. In this work, a bibliographical survey of the theories involving natural hybridity or interspecific reproduction between animals and consequences for species was carried out. It can be seen that this type of hybridization with the formation of fertile intermediates occurs frequently, and can be observed, for example, in the species of sea turtles Eretmochelys imbricata and Caretta caretta belonging to the Brazilian coast. In addition, from this hybridity they have not shown reproductive differences in relation to their parents and are reported in a relatively high incidence. The same occurs with the species of gulls Laurus glaucescens and L. occidentalis, belonging to a certain hybrid zone of North America, in which it is researched that their specimens of intermediaries will be as fertile as their parents. In other studies, bird species Pyriglena Atra and P. leucoptera that, despite the fertility of their intermediaries, highlighted results that are still inconclusive on the consequences of this reproduction. It was also possible to evaluate researches where hybridism can have negative consequences for the species involved, as occurred with species of marmosets Callithrix sp. found in Brazil where, due to anthropic actions, they shared the same habitat and a reproduction between them generated an ecological disturbance. In this way, the results obtained through the present bibliographic survey demonstrate that it is necessary to reevaluate as assumptions about species from natural hybridity, demystifying the rarity of the event in nature, in order to build a focus on fertility and evolutionary productivity in order to contribute with correlated studies of genetics and evolution of species.