Within words, only occurs between similar consonants, and seems to be explicable as epenthesis there as well, so that the only underlying vowels that need to be assumed are.
The first is the naturalistic way of understanding evolution as explicable entirely in terms of natural law without reference to a divine intention or intervention.
That is to say, it should be plausible and explicable biologically according to the known facts of the natural history and biology of the disease in question.
The few laboratory-based analyses have not found significant amounts of individual variation in aggression explicable by genetic variation in the human population.
