Since these souls are star energy, their next phase is to be born out of the waters (liquid matter) and become formed of earth (solid matter). Waters matter and earth matter are twin souls.
The soul of life in water is a form of the waters and has not yet been born out of the waters. The birth of the soul of life in matter (earth) out of the waters had to occur no later than simultaneous with the birth of the soul of life in darkness out of the waters.