HELLO, OMNIOLOGY! HAVE NOT HEARD YOUR SHOUTS IN A WHILE!
Maximinus Thrax, The Thracian was Emperor of the Roman Empire from 235 to 238 AD. Every major account of his life remarked on his massive build, gargantuan strength and cruel, barbarous nature. There seems to be some discrepancy about his date of birth. His height was 8'6" tall.
WHILE THIS WOULD BE EXTREMELY TALL EVEN FOR HUMAN GIGANTISM, HE WOULD NOT HAVE BEEN THE TALLEST DOCUMENTED MAN IN HISTORY. OF COURSE, HIS SIZE IS LIKELY TO HAVE BEEN EXAGGERATED, AND THIS IS FURTHER COMPLICATED BY CONVERSION OF HISTORICAL TO MODERN MEASURES.
THERE IS NO EXPLANATION FOR GIANTS IN HUMAN EVOLUTION.
EXCEPT THAT THE EVOLUTION OF GREAT SIZE IS A WELL ESTABLISHED PHENOMENON IN MANY GROUPS. FOR ONE THING, BEING TOO LARGE TO BE HUNTED IS A PRETTY GOOD PROTECTION AGAINST PREDATORS. EVOLUTIONARY GIGANTISM IS PARTICULARLY COMMON FOR NORMALLY SMALL CREATURES ON ISLANDS AND IN THE DEEP SEA.
AS FOR GIGANTISM IN THE SENSE OF BEING ABNORMALLY SIZE, WHILE WE DO NOT UNDERSTAND THE GENETICS WELL, WE KNOW THE PHYSIOLOGICAL CAUSE - EXCESS GROWTH HORMONE - AND SOME GENES THAT ARE LINKED TO SUCH MALFUNCTIONS. USUALLY COMES WITH SEVERE HEALTH PROBLEMS, WITH THESE DRAWBACKS OUTWEIGHING THE PRETTY MARGINAL BENEFITS.
MAN IS SUPPOSED TO HAVE EVOLVED UPWARD FROM TINY LITTLE MONKEYS WITH TINY LITTLE BRAINS.
EVOLUTION IS NOT TELEOLOGICAL!
THE BELIEF THAT "A LARGE BRAIN MEANS HIGHER INTELLIGENCE" PRESENTS A PROBLEM WHEN IT COMES TO GIANTS
IT IS WELL ESTABLISHED THAT THINGS ARE FAR MORE COMPLICATED THAN THAT. FOR THE MOST OBVIOUS, A LARGER OVERALL SIZE GENERALLY MEANS THAT THE ABSOLUTE SIZE OF THE BRAIN IS CORRESPONDINGLY LARGER, TOO. THE RELATIVE SIZE OF THE BRAIN AND EVEN MORE SO THE PROPORTIONS OF THE REGIONS OF THE BRAIN ARE FAR MORE IMPORTANT.