After evolving for so long, Wang Ye had roughly figured out the pattern of his body's evolution. Whenever he particularly needed a certain ability, his body's direction of evolution would unconsciously move towards that.
For instance, when he evolved powerful jaw muscles and fangs, it was actually during a period of severe food scarcity to supplement nutrition. Another example was when he evolved gill slits, which happened when he was frequently diving into lakes, holding his breath to catch fish. But when he had no special needs, his evolution direction was just ordinary physical enhancement.
Although most of the current physical mutations seemed to resemble ancestral regression.
Yet, these were actually choices made subconsciously by Wang Ye. Because his subconscious believed these evolutionary traits would give him better survival capability.
Similarly, if he wanted to evolve more resilient bones, or even bones of different materials.
