Who knows where life comes from?
The Bible says God created man. Muslims believe that when God wants to create something, he creates it. Hindus believe that this is just one of an infinite number of "worlds" - created, preserved and destroyed by Brahma, Vishnu and Shiva. Buddhism doesn't consider such things. The Greeks, Romans, Egyptians, Mayans and Native Americans all had different stories to explain the existence of the universe and of mankind. They are all extremely high-level - and let's be honest - suitable for an audience of young children.
It's more interesting to consider the question of how and where life originated from - and maybe some of the high-level mechanisms - if you're an adult with an above-average curiosity and an ability to understand complex concepts. Scientists have, over the years, had differing hypotheses about the origin of life on planet Earth. At one time, learned men thought that life spontaneously arose from nothing - although Louis Pasteur put the kibosh on that idea. There is also the "primordial soup", panspermia and its close cousin exogenesis, and other hypotheses. Now, an interesting article at the Daily Galaxy notes that bacteria has been found living close to a mile under the bottom of the ocean. They are "SAR11" ... the simplest and most abundant bacteria in the ocean. Interesting factoid: "a milliliter of sea water ... might contain 500,000 of these cells".
Some scientists think that life didn't arise from the primordial soup, but instead required clay, shale or other substrates in order to organize the components of what would then become cells - bacteria, for instance. This new discovery raises some interesting possibilities - could life arise deep in the earth?