Experts developed a method of calculating the height and body mass of humans from small fossil bones , some no bigger than toes . Researchers found early man ranged from 4 ft 8 inches to almost 6 ft . It has been said ancestors left Africa as a result of developing longer legs . But this study suggests that there may have been another driving force . Experts also claim regional conditions may be to blame for diverse shapes . This suggests body size is not a fixed characteristic of a species . It is the first study in 20 years to compare the body size of humans who lived between 1.5 million and 2.5 million years ago .
Experts developed a method of calculating the height and body mass of individuals from small fossil fragments , some no bigger than toes . Researchers found early man ranged from 4ft 8 inches to almost 6ft . It has been said ancestors left Africa as a result of developing longer legs . But this study suggests that there may have been another driving force . Experts also claim regional conditions may be to blame for diverse shapes . This suggests body size is not a fixed characteristic of a species . It is the first study in 20 years to compare the body size of humans who lived between 1.5 million and 2.5 million years ago .