Science shows us that the universe evolved by self-organization of matter towards more and more complex structures. Atoms, stars and galaxies self-assembled out of the fundamental particles produced by the Big Bang. In first-generation stars, heavier elements like carbon, nitrogen and oxygen were formed. Aging first-generation stars then expelled them out into space – we, who consist of these elements, are thus literally born from stardust. The heaviest elements were born in the explosions of supernovae. The forces of gravity subsequently allowed for the formation of newer stars and of planets. Finally, in the process of biological evolution from bacteria-like tiny cells (the last universal common ancestor, abbr. LUCA) to all life on earth, including us humans, complex life forms arose from simpler ones.

Upon considering this self-organization of material structures in the realm of philosophy, one may conclude that it happens either because the underlying laws of nature, which have to be exceedingly special to allow for it , simply are the way they are  or because they were designed by God for this purpose. Since we know that the laws of nature are so self-sufficient that, based on them, the complexity of the entire physical universe evolved from fundamental particles, and further, complex life forms from simpler ones during biological evolution, we can reasonably extrapolate that they would also allow life itself to originate spontaneously, by chemical evolution of suitable structures – regardless if we believe these laws are designed or undersigned. Therefore, we should expect an origin of life by natural causes from both theistic and atheistic philosophical perspectives.

 this is gradual build up of complexity