In a spontaneous manner; naturally; voluntarily.(adverb)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "spontaneously" in a sentence
"The bottom line for all of this is the multifaceted observation that atoms join spontaneously to form molecules, consistent with energy relationships."
"In regard to the theological level of this theme of variation in complex systems, I loved the notion of "God" being the consciousness of nature, emerging -- like Cylon self-awareness, or genetic variations -- spontaneously from the sheer complexity of the universe."
""The problem of how meaningful or semantic information can emerge spontaneously from a collection of mindless molecules subject to blind and purposeless forces presents a deep conceptual challenge.""