Popular perceptions of our ancient human ancestors picture a strict division of labour between the sexes – man the hunter and woman the gatherer. Recent research by Cara Ocobock, a biologist at Notre Dame University, and Sarah Lacy, an anthropologist at the University of Delaware, strongly challenges this picture, offering strong evidence that women were also heavily involved in hunting. Their research was summarised by Tracy DeStazio in, Notre Dame News.
The traditional picture assumed that men were biologically superior to women when it came to hunting big-game, where the animals must be run to exhaustion and then killed at close quarters. This involved chasing animals to a standstill over distances averaging about 13 miles. But, modern biochemistry tells us that, contrary to the stereotype, the female body is better equipped than the male body for such arduous running.
Two hormones, oestrogen and adiponectin, present in the female body in higher concentrations than in males, enhance female muscle metabolism relative to male metabolism, facilitating endurance running. The fuels that power the muscles involved in running are carbohydrates and lipids.
Lipids are considerably more energy-dense than carbohydrates, and oestrogen and adiponectin allow female muscles to extract energy from the fuel mix more efficiently than male muscles, thereby enhancing female athletic performance. They stimulate muscle cells to use stored lipid fuel for energy before using carbohydrate.
Because of the higher energy-density of lipid, female muscle gets a slower, longer “burn”, thereby helping women to run longer before fatigue sets in. Oestrogen also protects body cells from heat damage during extreme exercise and speeds recovery from injury.
Why then do top male marathon runners now clock faster times than top female runners?
The female anatomy also helps long-distance running. Women have wider hips than males and they can rotate them more and so lengthen their steps. With longer steps and leaner energy metabolism, women are better-equipped to travel longer distances faster than men. Female muscles also have a higher proportion of cells (fibres) called slow-twitch fibres, than male muscles, which have a higher proportion of fast-twitch fibres. Slow-twitch fibres are better adapted to endurance running.
Why then do top male marathon runners now clock faster times than top female runners? The male winner of the 2023 Dublin City Marathon clocked two hours, 11 minutes and 51 seconds while the best female time was two hours, 34 minutes and 13 seconds. The answer is that, on average, men have bigger and more powerful muscles than women and consequently have a distinct advantage over women in power events such as weightlifting. The marathon is 26.2 miles long and top athletes run the race at close to maximum power output over the duration. Therefore, men have a small advantage over women at this race length.
However, ultra-marathons (31 miles, 50 miles, 100 miles and longer) are not run at near maximum power outputs over the duration. Women now have the advantage and regularly win these events in mixed fields. For example, Jasmin Paris won the gruelling 268-mile UK Montane Spine Race in 2019, beating 136 others, including 125 men. Her winning time set a brilliant new record of 83 hours, 12 minutes and 23 seconds, smashing the previous record set by a man, Eoin Keith, in 2016 of 95 hours and 17 minutes.
Hunters would regularly suffer substantial injuries, and early human remains, both male and female, equally display these injuries
So, women were physiologically and anatomically better equipped than men to hunt large game – but did they do so? Yes, it certainly seems they did. Hunting large game to exhaustion is only half the battle: the animals must then be killed at close quarters. This is very risky for the hunter because these exhausted animals remain dangerous – they can kick and bite and gore with their horns.
Hunters would regularly suffer substantial injuries, and early human remains, both male and female, equally display these injuries. The injuries seen are very similar to injuries received by present-day rodeo clowns – injuries from kicks to the head and chest and bite and fracture injuries to limbs.
The findings of early women buried with hunting tools also heightens the probability that hunting big animals was an important female activity. In summary, there is no evidence from the deep past that strict division of labour existed on grounds of sex. It appears all adults were involved in hunting, not just men. Anyway, early human groups were too small for subgroups specialised in different tasks to make sense.
William Reville is an emeritus professor of biochemistry at UCC