Problem Statement : evolution of life ....single cell life like ameoba , algae...and human the most evoluted form rationalize how digestion works. Arrguments: understanding the digestive system in ameoba ....rationalizing the same with how human digestive system works analyzing the role of light or vitamin D. Note: The above problem statement having been encountered in various scenarios and detailed in various 'Proof of concepts' as mentioned in 'http://uk.geocities.com/ravivenkatus/projects.pdf' ....apply appropriate 'use-case' modeling and arrive at a workable and feasible solution both commercially and techinically viable. -------------------------------------------------------------------------------------------------------------------------------------------------------------