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.
Mixed-age groupings: In a mixed-age preschool class of 2.5-5 year-olds, no more than four children between the ages of 30 months and 36 months may be enrolled and the ratios within group size for the predominant age group apply. If infants or toddlers are in a mixed-age group, the ratio for the youngest child applies. For a group of 10 children, in a Toddler/Two group with ages 12 months to 28 months, there must be 3 teaching staff to meet.