Olympic athletes may benefit from today's sports drinks and high-tech training, but their gymnastics or wrestling performance probably pales in comparison to what early human ancestors could have pulled off.
That's because we Homo sapiens have followed an evolutionary track away from sheer body strength and toward the lean, mean endurance qualities of a long-distance runner.
"The chimp-like ancestor was like a power athlete," said Dan Lieberman, a biological anthropologist at Harvard University. "Much stronger and faster than humans, but they had no endurance."
Neanderthals, who coexisted with Homo sapiens until roughly 20,000 years ago, may have also posed a challenge to modern humans in terms of power. However, many experts agree that early Homo sapiens were not much different from the burly Neanderthals — the biggest evolutionary change had already taken place roughly 2 million years ago when human ancestors became serious runners.
So in a hypothetical competition, if you wanted to bet on modern Olympic athletes besting earlier humans, choose the endurance events such as the triathalon or soccer. Otherwise the power sports would belong to human ancestors, and for good reason.
The power athletes
For instance, before 2 million years ago, the earliest human ancestors such as Australopithecus afarensis (represented in part by the famed "Lucy" fossil) had just come down from the trees in an evolutionary sense. Their bodies still reflected chimp features such as longer arms and a stronger upper body built for fighting and swinging through the trees.
"A big male chimp weighs about 50 kilos [110 pounds], yet could easily rip the arm off someone," Lieberman noted. "You would never want to arm wrestle a chimpanzee."
The build of Australopithecus unsurprisingly continued the ape trend toward male-male physical competition, said David Carrier, a biologist at the University of Utah. The smaller human ancestor would have had an advantage in fighting sports such as wrestling, especially if the size advantage of modern humans was removed.
The same physical advantages would have extended to other Olympic sports as well.
"The Australopiths would really excel at gymnastics and diving because of the greater upper body strength, longer arms," Carrier told LiveScience. "Their short stature and low body mass would also have greatly increased their ability to do flips and spins because of the low rotational inertia of their body."
Yet when it came to running, Australopithecus found itself in an awkward position of having just learned to walk comfortably on two legs.
"Australopithecus represented a biped on the ground with much more climbing ability and without striding locomotion," said Ian Tattersall, anthropologist and curator for the American Museum of Natural History in New York City. "Running would have been possible, but probably not as efficient."
The most dangerous game
The ability to run for long distances changed human athleticism — as well as history — and came around the 2-million year mark, allowing human ancestors such as Homo erectus to hunt seriously for the first time.
Early hunters only had sharpened wooden sticks and clubs, which meant that success in catching and killing prey relied on the difference between human marathon running and animal sprinting.
"Most human sports that we value the most (with exception of power sports) involve this incredible ability to run or do aerobic capacity," Lieberman said. "That's really rare. Very few animals adapted for endurance."
Lions can run about twice as fast as the fastest Olympic sprinters over short distances to catch their prey. Early humans relied instead upon tiring their prey by running them down to exhaustion, combining a springy step with sweat glands all over the body that prevented overheating.
Modern Olympic marathoners could take full advantage of their running to beat early human ancestors such as Australopithecus in a long-distance race. Even contemporary people who still rely on persistence hunting without long-range weapons can run with equal ease, such as the Tarahumara of northern Mexico.
"Kids on lunch break will go run ten miles," Lieberman noted. "The Tarahumara used to run deer down to exhaustion."
A caveman can do it
The long-running Homo sapiens may seem very different from its relative the Neanderthal, which overlapped with prehistoric humans on Earth until it vanished about 20,000 years ago. But experts say that the similarity is greater than previously thought, and that our modern perceptions have become skewed by modern living.
"If you compare [Neanderthals] to yourself or most people probably living in mechanized urban areas, the Neanderthals would appear very strong," said Erik Trinkaus, a physical anthropologist at Washington University in St. Louis. "However, if you compared them to early modern humans, the Neanderthals and early humans would not appear very different."
Trinkaus said that prehistoric humans would have developed similar or greater strength due to their hunter-gatherer lifestyle, a view that he has gradually come to embrace during his professional career.
"Going to the gym, going on a bike ride, even most Olympic training doesn't do the same thing as having the same serious level of lifting, walking that people have done in the past," Trinkaus explained.
Some debate still exists as to whether the main physiological differences made a difference, such as wider-spaced hips making Neanderthals less efficient at long-distance running. But for the most part, other experts agree that even some humans today likely resemble Neanderthals in physical terms.
"Neanderthals were somewhat shorter and stockier than the average sapiens, but there are modern humans with the same proportions," Carrier said. Lieberman described Neanderthals as "basically like robust early humans."
Both Homo sapiens and Neanderthals certainly shared a definitive advantage over the earlier Australopithecus — males and females became much more equal in body strength and size. Modern Olympic athletes have increasingly embraced that trend.
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