Evolution of fighters

As a result of sporting events, martial arts training, information sharing, and modern kinesiology, the understanding of the combat-effectiveness of various strategies has been greatly improved. UFC commentator Joe Rogan has claimed that martial arts have evolved more in the ten years following 1993 than in the preceding 700 years.[22]
The early years of the sport saw a wide variety of traditional styles—everything from sumo to kickboxing— and the continual evolution of the sport has gradually eliminated less effective techniques and "pure" styles, usually because specialized fighters were lacking in skills to deal with broader techniques.
In the early 1990s, three styles stood out for their effectiveness in competition: Brazilian Jiu-Jitsu, amateur wrestling and shoot wrestling. This may be attributable in part to the grappling emphasis of the aforementioned styles, which, perhaps due to the scarcity of mixed martial arts competitions prior to the early 90s, had been neglected by most practitioners of striking-based arts.
Fighters who combined amateur wrestling with striking techniques dominated the standing portion of a fight, whilst Brazilian Jiu-Jitsu stylists had a distinct advantage on the ground: those unfamiliar with submission grappling proved to be unprepared to deal with its submission techniques. Shoot wrestling practitioners offered a balance of amateur wrestling ability and catch wrestling based submissions, resulting in a generally well-rounded set of skills. The shoot wrestlers were especially successful in Japan, where this style initially dominated others.
As competitions became more and more common, those with a base in striking became more competitive as they acquainted themselves with takedowns and submission holds, leading to notable upsets against the then dominant grapplers. Subsequently, those from the varying grappling styles learned from each other's strengths and shortcomings, and added striking techniques to their arsenal. This overall development of increased cross-training resulted in the fighters becoming increasingly multi-dimensional and well-rounded in their skills. One of the first fighters to be considered the prototype for mixed martial arts was UFC middleweight champion, Frank Shamrock. "During his reign atop the sport in the late 1990s he was the prototype — he could strike with the best strikers; he could grapple with the best grapplers; his endurance was second to none."[23]

http://en.wikipedia.org/wiki/Mixed_martial_arts