In Indian culture, various species were regarded as being on a certain place in a spectrum of consciousness. Vedic literatures regarded even plants as beings who can have feelings. From zero (a rock) to almost 100% (a human) differentiation of species was primarily based on level of consciousness (bodily features as another factor, ofcourse) and interestingly, according to philosophy, selection of a specific species depended on a living entities 'karma', one gets a body with a certain level of consciousness according to the 'good' or 'bad' deeds one does in ones life.