While the functional elements of MEMS are miniaturized structures, sensors, actuators, and microelectronics, the most notable (and perhaps most interesting) elements are the microsensors and microactuators.
The horse (Equus caballus) has made many dramatic and significant journeys. During the Pleistocene (Ice Age), more than 20,000 years ago, wild horses that had evolved in America migrated to the Old World, Eurasia and Africa. More than 6,000 year ago in the Volga basin of eastern Europe horses were domesticated and in the subsequent millennia spread to other parts of Asia, Europe, and Africa.
The basic story line goes like this: as the woodlands of North America gave way to grassy plains, the tiny proto-horses of the Eocene epoch (about 50 million years ago) gradually evolved single, large toes on their feet, more sophisticated teeth, larger sizes and the ability to run at a clip, culminating in the modern horse genus Equus.