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.
According to developmental studies (and don't ask me why age 5 is an overlap, I am not the one whom created these): 1  Newborn 0-3 months. 2  Infant 4-12 months. 3  Toddler 13 months to 35 months.  Preschooler 3-5 1  yrs. Kindergartener 5-6 yrs (I included this because it is good to know.)