What does neil degrasse tyson use as a metaphor for how we are born into a universe of mystery?

Neil Degrasse Tyson used the phrase “like an abandoned baby” when he describes how the people are born into a universe of mystery.  He uses this phrase in order to give a fact that we don’t have a definite or certain origin, just like and abandoned child.

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.

cell division is not regulated in tumor cells.