Baraminology is the study of baramins, also known by the Biblical term kinds.
A baramin is a lineage of earthly life which is believed by Young Earth Creationists to be created by God during the creation week, and corresponds in some functional aspects to the secular concept of species. However, unlike species concepts that are based on Darwinian thinking, the baraminic barrier is inviolable, as other baramins do not evolve from earlier baramins.
Jonathan Sarfati writes regarding the Biblical kinds of organisms:
Based on the Biblical criterion for kinds, creationists deduce that as long as two creatures can hybridize with true fertilization, the two creatures are (i.e. descended from) the same kind. Also, if two creatures can hybridize with the same third creature, they are all members of the same kind. The hybridization criterion is a valid operational definition, which could in principle enable researchers to list all the kinds. The implication is one-way—hybridization is evidence that they are the same kind, but it does not necessarily follow that if hybridization cannot occur then they are not members of the same kind (failure to hybridize could be due to degenerative mutations). After all, there are couples who can’t have children, and we don’t classify them as a different species, let alone a different kind.