Know both Prakṛti (Nature) and Purusha (the Soul) as beginningless (transcending time). Know all modifications and qualities as born of Prakṛti alone. (Purusha remains ever the same).
Prakṛti (Nature) consists of the five elements, pañca-bhūtas, which are beginningless. None can say when they emerged or evolved. So also the Purusha, the conscious source to mould them further into life forms with varying capacities, is beginningless.
Prakṛti, an aggregate, is subject to changes, as each of its constituents will act upon the others, leading to endless actions and reactions. But this is only within the elements of Prakṛti. As for Purusha, He only enables the whole process to be on, remaining a facilitator, not involved in it the least.
Time, causality, and changes – all are within the ken of Nature. But Nature as a whole and its conscious substratum, the Purusha, are eternal, transcending time.