People have shared stories about giants for thousands of years, from the Cyclops of Greek mythology to the biblical Goliath. But are they just tall tales, or did giants really walk the earth?
If you consider a nearly 9-foot-tall human to be a giant, then yes. Robert Wadlow, the tallest man in history, grew to 8 feet, 11 inches (2.72 meters) before he died at the age of 22 in 1940, according to Guinness Book of Records.
Wadlow was well above the current Average height of men in the US about 5 feet, 9 inches (1.75 m) and even taller than some interpretations biblical descriptions of Goliath. Yet there was nothing magical about Wadlow. As with most true giants, his stature resulted from a medical condition.
“Most [giant] patients have a growth hormone problem,” Márta Korbonitsová, professor of endocrinology at Queen Mary University of London, told Live Science. “Robert Wadlow had that.
Korbonits noted that the main cause of gigantism is increased levels of growth hormone produced by the pituitary gland in the brain. These high levels are usually caused by a benign tumor. One of the reasons we’re unlikely to see another person as tall as Wadlow again is that doctors can now remove the tumor and use drugs to stop growth because gigantism and tumor threaten a person’s health.
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Other conditions can cause people to be extraordinarily tall. These include Marfan syndrome, a genetic disorder that causes bones to grow longer, Korbonits explained.
However, some people grow to extreme heights without a known medical condition; include the former tallest man in the world, Bao Xishun, who stands 7 feet, 9 inches (2.36 m)—a giant without gigantism. They likely have a set of genetic variants that predispose them to tall stature, Korbonits said.
Although it is easier for researchers to study giants living in modern times, extremely tall people have probably always been around. The the oldest known case of gigantism comes from the alleged remains of an ancient Egyptian pharaoh who was about 6 feet, 1.6 inches (1.87 m), while Korbonits’ research found that many in real life irish giants inherited a gene mutation from a human who lived 2500 years ago.
“We’ve had these diseases for as long as humanity has existed, so there’s no reason why you wouldn’t have these giants in ancient Egypt or any other time in human history,” Korbonits said.
Genetics combine with environmental factors such as diet early in life determine the height, with populations often increasing over time as civilization advances. However, it is not always a linear trend.
Pavel Grasgruberresearcher from Masaryk University in Brno, told Live Science that some male skeletons from the late phase of the mammoth-hunting Gravettian culture from 29,000 years ago stand out for their extraordinary height and even helped inspire giant myths. The tallest of these seven skeletons, excavated in the Grimaldi cave system in Italy at the turn of the 19th and 20th centuries, is estimated to stand 6 feet, 5 inches (1.96 m).
“Consider that at the time these skeletons were found, the standard for male height in Europe was under 170 cm. [5 feet, 7 inches]!” Grasgruber said in an email. “No wonder these people must have seemed like ‘giants’ to scientists at the time.”
The researchers do not know if the tall remains represented the Gravettian population. Grasgruber nevertheless noted that tall males were typical of early Paleolithic populations in France and the historical region of Moravia (today’s Czech Republic) and reached heights that modern industrialized nations only reached in the mid-20th century.
“The reason for this good physical condition of early Paleolithic hunters was the low population density and the abundance of game in the form of mammoths and other large mammals,” Grasgruber said.