Primates originated in cold environments, not the tropics:
It is easy to see why scientists had assumed primates evolved in warm and wet climates. Most primates today live in the tropics, and most primate fossils have been unearthed there too.
But when the scientists behind the new study used fossil spore and pollen data from early primate fossil environs to predict the climate, they discovered that the locations were not tropical at the time. Primates actually originated in North America (again, going against what scientists had once believed, partly as there are no primates in North America today).
Some primates even colonized Arctic regions. These early primates may have survived seasonally cold temperatures and a consequent lack of food by living much like species of mouse lemur and dwarf lemur do today: by slowing down their metabolism and even hibernating.
Challenging and changeable conditions are likely to have favored primates that moved around a lot in search of food and better habitat. The primate species that are with us today are descended from these highly mobile ancestors. Those less able to move didn’t leave any descendants alive today.