More clearly stated:

• Why do some organisms begin as single cells, grow extremely large and specialized, only to reproduce through single cells?

The answer is broken up into three reasons:

• 1. Starting from a single cell is similar to going back to the drawing board or hitting the restart button. If organisms were to bud off of their parents at full size, they would be carrying some of their parents physical baggage and wear with them.
• 2. It provides a calendar for development. Organisms can strategically reproduce based on convenient times in the season and their life cycle, "knowing" when to start and how long it will take to come to fruition.
• 3. Mutations can be "tested" independently. When a reproductive cell has a mutation, it will grow into an individual that has that mutation in all of its cell, testing that mutations impact on survival.