Though in an attempt to answer the thread, it's usual that with a stable set of regulations different constructors will "evolve" towards a more similar design and field spread reduces. That's how I interpret the question.
This is a very interesting topic, as one observes the natural evolution of grand prix cars from 1905 through to 2015.
Past evolution in Grand Prix Racing was about chasing performance...
Wire wheels instead of wooden wheels - increased performance
Tubeframe instead of the traditional ladder chassis - increased performance
Disc brakes - performance increase compared to drums on early cars
Independent suspension - performance
Supercharging - performance (remember in those days there was a maximum weight)
Overhead cams - performance
Engine in the middle - performance
Aluminium monocoque instead of tubeframe - performance
Engine as stressed member - performance
Aerodynamic downforce - performance
Ground effects - performance
Sliding skirts - performance
Maturation of turbocharging - performance
Carbon fibre chassis - performance
ABS - performace
Active suspension - performance
Tractional control - performance
Beryllium coated pistons - performance
Increasing rpm of the engines - perfromance
Need I go on?
Hybrid - well it's much heavier and hugely complicated. It seems a matter of regulation NOT the teams chasing performance on their own accord of natural evolution of grand prix racing cars.
Edited by V8 Fireworks, 14 July 2015 - 02:19.