Difference Between Convergent and Divergent Evolution. When considering living organisms, evolution can be defined as the development of differentiated organisms from less differentiated pre-existing organisms over the course of time. There are many sources, which provide evidence to the theory of evolution.
You're apparently differentiating between daycare and preschool, right? Private preschools (about $500 per month for three days per week, 9:00a to 1:00p) typically have a minimum age of 30 months (2.5 years) and potty-trained.
Photo credit: Juan Silva/Getty Images. A preschool is a school for children who are too young for kindergarten. The ages range typically between 2.9 and 3 years old and ending around 5 years old (except for those schools who offer kindergarten for those who don't make the cut off date).