'Woman the hunter': Studies aim to correct history

When Cara Ocobock was a young child, she often wondered at the images in movies, books, comics and cartoons portraying prehistoric men and women as such: "man the hunter" with spear in hand, accompanied by "woman the gatherer" with a baby strapped to her back and a basket of crop seeds in hand.

"This was what everyone was used to seeing," Ocobock said. "This was the assumption that we've all just had in our minds and that was carried through in our museums of natural history."

Many years later, Ocobock, an assistant professor in the Department of Anthropology and director of the Human Energetics Laboratory at the University of Notre Dame, found herself as a human biologist studying physiology and prehistoric evidence and discovering that many of these conceptions about early women and men weren't quite accurate. The accepted reconstruction of human evolution assumed males were biologically superior, but that interpretation wasn't telling the whole story.

Relying on both physiological and archaeological evidence, Ocobock and her research partner, Sarah Lacy, an anthropologist with expertise in biological archaeology at the University of Delaware, recently published two studies simultaneously in the journal American Anthropologist. Their joint research, coming from these two angles, found that not only did prehistoric women engage in the practice of hunting, but their female anatomy and biology would have made them intrinsically better suited for it.

Of her and her co-author's dual-pronged research, which was the cover story for the November issue of Scientific American, Ocobock said, "Rather than viewing it as a way of erasing or rewriting history, our studies are trying to correct the history that erased women from it."

Female physiology and estrogen, the 'unsung hero of life'

In their physiological study, the two researchers explained that prehistoric females were quite capable of performing the arduous physical task of hunting prey and were likely able to hunt successfully over prolonged periods of time. From a metabolic standpoint, Ocobock explained, the female body is better suited for endurance activity, "which would have been critical in early hunting because they would have had to run the animals down into exhaustion before actually going in for the kill."

Two huge contributors to that enhanced metabolism are hormones -- in this case, estrogen and adiponectin, which are typically present in higher quantities in female bodies than in male. These two hormones play a critical role in enabling the female body to modulate glucose and fat, a function that is key in athletic performance.

Estrogen, in particular, helps regulate fat metabolism by encouraging the body to use its stored fat for energy before using up its carbohydrate stores. "Since fat contains more calories than carbs do, it's a longer, slower burn," Ocobock explained, "which means that the same sustained energy can keep you going longer and can delay fatigue."

Estrogen also protects the body's cells from damage during heat exposure due to extreme physical activity. "Estrogen is really the unsung hero of life, in my mind," Ocobock said. "It is so important for cardiovascular and metabolic health, brain development and injury recovery."

Adiponectin also amplifies fat metabolism while sparing carbohydrate and/or protein metabolism, allowing the body to stay the course during extended periods, especially over great distances. In this way, adiponectin is able to protect the muscles from breaking down and keeps them in better condition for sustained exercise, Ocobock explained.

The female body structure itself is another element Ocobock and Lacy found to be of advantage in terms of endurance and effectiveness for prehistoric hunters. "With the typically wider hip structure of the female, they are able to rotate their hips, lengthening their steps," Ocobock detailed. "The longer steps you can take, the 'cheaper' they are metabolically, and the farther you can get, faster.

"When you look at human physiology this way, you can think of women as the marathon runners versus men as the powerlifters."

Archaeology tells more of the story of 'woman the hunter'

Several archaeological findings indicate prehistoric women not only shared in the resulting injuries of the dangerous business of close-contact hunting, but that it was an activity held in high esteem and valued by them. "We have constructed Neandertal hunting as an up-close-and-personal style of hunting," Ocobock said, "meaning that hunters would often have to get up underneath their prey in order to kill them. As such, we find that both males and females have the same resulting injuries when we look at their fossil records."

Ocobock described those traumatic injuries as being similar to those received by modern-day rodeo clowns -- injuries to the head and chest where they were kicked by the animal, or to the limbs where they were bitten or received a fracture. "We find these patterns and rates of wear and tear equally in both women and men," she said. "So they were both participating in ambush-style hunting of large game animals."

Second, Ocobock said, there is evidence of early female hunters in the Holocene period in Peru where females were buried with hunting weapons. "You don't often get buried with something unless it was important to you or was something that you used frequently in your life.

"Furthermore, we have no reason to believe that prehistoric women abandoned their hunting while pregnant, breastfeeding or carrying children," Ocobock added, "nor do we see in the deep past any indication that a strict sexual division of labor existed."

The bottom line, Ocobock noted, was that "hunting belonged to everyone, not just to males," especially in prehistoric societies where survival was an all-hands-on-deck activity. "There weren't enough people living in groups to be specialized in different tasks. Everyone had to be a generalist to survive."

Fighting bias

"This revelation is especially important in the current political moment of our society where sex and gender are in a spotlight," Ocobock said. "And I want people to be able to change these ideas of female physical inferiority that have been around for so long."

When talking about reconstructing the past in order to better understand it -- and to conduct "good science" -- Ocobock said scientists have to be extremely careful about how modern-day bias can seep into one's interpretations of the past. She cautioned that researchers have to be aware of their own biases and make sure they are asking the proper questions so the questions don't lead them down the road of looking for what it is they want to see.

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Spear thrower weapon use by prehistoric females equalized the division of labor while hunting

A new study led by Archaeologist Michelle Bebber, Ph.D., an assistant professor in Kent State University's Department of Anthropology, has demonstrated that the atlatl (i.e. spear thrower) functions as an "equalizer," a finding which supports women's potential active role as prehistoric hunters.

Bebber co-authored an article "Atlatl use equalizes female and male projectile weapon velocity" which was published in the journal Nature: Scientific Reports. Her co-authors include Metin I. Eren and Dexter Zirkle (a recent Ph.D. graduate) also in the Department of Anthropology at Kent State, Briggs Buchanan of University of Tulsa, and Robert Walker of the University of Missouri.

The atlatl is a handheld, rod-shaped device that employs leverage to launch a dart, and represents a major human technological innovation used in hunting and warfare since the Stone Age. The first javelins are at least hundreds of thousands of years old; the first atlatls are likely at least tens of thousands of years old.

"One hypothesis for forager atlatl adoption over its presumed predecessor, the thrown javelin, is that a diverse array of people could achieve equal performance results, thereby facilitating inclusive participation of more people in hunting activities," Bebber said.

Bebber's study tested this hypothesis via a systematic assessment of 2,160 weapon launch events by 108 people, all novices, (many of which were Kent State students) who used both javelins and atlatls. The results are consistent with the "atlatl equalizer hypothesis," showing that the atlatl not only increases the velocity of projectile weapons relative to thrown javelins, but that the atlatl equalizes the velocity of female- and male-launched projectiles.

"This result indicates that a javelin to atlatl transition would have promoted a unification, rather than division, of labor," Bebber said. "Our results suggest that female and male interments with atlatl weaponry should be interpreted similarly, and in some archaeological contexts females could have been the atlatl's inventor."

"Many people tend to view women in the past as passive and that only males were hunters, but increasingly that does not seem to be the case," Bebber said. "Indeed, and perhaps most importantly, there seems to be a growing consilience among different fields -- archaeology, ethnography, and now modern experiments -- that women were likely active and successful hunters of game, big and small."

Since 2019, every semester Bebber takes her class outside to use the atlatl. She noticed that females picked it up very easily and could launch darts as far as the males with little effort.

"Often males became frustrated because they were trying too hard and attempting to use their strength to launch the darts," Bebber said. "However, since the atlatl functions as a simple lever, it reduces the advantage of male's generally greater muscle strength."

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Tooth enamel provides clues to hunter-gatherer lifestyle of Neanderthals

A study by an international team of researchers, led by the University of Southampton, has given an intriguing glimpse of the hunting habits and diets of Neanderthals and other humans living in western Europe.

The scientists examined chemical properties locked inside tooth enamel to piece together how pre-historic people lived off the land around the Almonda Cave system, near Torres Novas in central Portugal almost 100 thousand years ago.

Their findings, published in the journal PNAS, show Neanderthals in the region were hunting fairly large animals across wide tracts of land, whereas humans living in the same location tens of thousands of years later survived on smaller creatures in an area half the size.

Strontium isotopes in rocks gradually change over millions of years because of radioactive processes. This means they vary from place to place depending on the age of the underlying geology. As rocks weather, the isotopic 'fingerprints' are passed into plants via sediments, and make their way along the food chain -- eventually passing into tooth enamel.

In this study, archaeologists used a technique which laser samples enamel and makes thousands of individual strontium isotope measurements along the growth of a tooth crown. Samples were taken from two Neanderthals, dating back about 95,000 years, and from a more recent human who lived about 13,000 years ago, during the Magdalenian period.

The scientists also looked at isotopes in the tooth enamel of animals found in the cave system. Alongside strontium, they measured oxygen isotopes, which vary seasonally from summer to winter. This enabled them to establish not only where the animals ranged across the landscape, but in which seasons they were available for hunting.

The team showed that the Neanderthals, who were targeting large animals, could have hunted wild goat in the summer, whereas horses, red deer and an extinct form of rhinoceros were available all year round within about 30km of the cave. The Magdalenian individual showed a different pattern of subsistence, with seasonal movement of about 20km from the Almonda caves to the banks of the Tagus River, and a diet which included rabbits, red deer, wild goat and freshwater fish.

The researchers approximated the territory of the two different human groups, revealing contrasting results. The Neanderthals obtained their food over approximately 600 km2, whereas the Magdalenian individuals occupied a much smaller territory of about 300 km2.

Lead author, Dr Bethan Linscott who conducted the research while at the University of Southampton and who now works at the University of Oxford said: "Tooth enamel forms incrementally, and so represents a time series that records the geological origin of the food an individual ate.

"Using laser ablation, we can measure the variation of strontium isotopes over the two or three years it takes for the enamel to form. By comparing the strontium isotopes in the teeth with sediments collected at different locations in the region, we were able to map the movements of the Neanderthals and the Magdalenian individual. The geology around the Almonda caves is highly variable, making it possible to spot movement of just a few kms."

Co-author, Professor Alistair Pike of the University of Southampton, who supervised the research said: "This study shows just how much science has changed our understanding of archaeology in the past decade. Previously, the lives and behaviours of past individuals was limited to what we could infer from marks on their bones or the artefacts they used. Now, using the chemistry of bones and teeth, we can begin to reconstruct individual life histories, even as far back as the Neanderthals."

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Hunting in savanna-like landscapes may have poured jet fuel on brain evolution

African savanna

Ever wonder how land animals like humans evolved to become smarter than their aquatic ancestors? You can thank the ground you walk on.

Northwestern University researchers recently discovered that complex landscapes -- dotted with trees, bushes, boulders and knolls -- might have helped land-dwelling animals evolve higher intelligence than their aquatic ancestors.

Compared to the vast emptiness of open water, land is rife with obstacles and occlusions. By providing prey with spaces to hide and predators with cover for sneak attacks, the habitats possible on land may have helped give rise to planning strategies -- rather than those based on habit -- for many of those animals.

But the researchers found that planning did not give our ancestors the upper hand in all landscapes. The researchers' simulations show there is a Goldilocks level of barriers -- not too few and not too many -- to a predator's perception, in which the advantage of planning really shines. In simple landscapes like open ground or packed landscapes like dense jungle, there was no advantage.

"All animals -- on land or in water -- had the same amount of time to evolve, so why do land animals have most of the smarts?" asked Northwestern's Malcolm MacIver, who led the study. "Our work shows that it's not just about what's in the head but also about what's in the environment."

And, no, dolphins and whales do not fall into the category of less intelligent sea creatures. Both are land mammals that recently (evolutionarily speaking) returned to water.

The paper will be published June 16 in the journal Nature Communications.

It is the latest in a series of studies conducted by MacIver that advance a theory of how land animals evolved the ability to plan. In a follow-up study now underway with Dan Dombeck, a professor of neurobiology at Northwestern, MacIver will put the predictions generated by this computational study to the test through experiments with small animals in a robotic reconfigurable environment.

MacIver is a professor of biomedical and mechanical engineering in Northwestern's McCormick School of Engineering and a professor of neurobiology in the Weinberg College of Arts and Sciences. Ugurcan Mugan, a Ph.D. candidate in MacIver's laboratory, is the paper's first author.

Simulating survival

In previous work, MacIver showed that when animals started invading land 385 million years ago, they gained the ability to see around a hundred times farther than they could in water. MacIver hypothesized that being a predator or a prey in the context of being able to see so much farther might require more brain power than hunting through empty, open water. However, the supercomputer simulations for the new study (35 years of calculations on a single PC) revealed that although seeing farther is necessary to advantage planning, it's not sufficient. Instead, only a combination of long-range vision and landscapes with a mix of open areas and more densely vegetated zones resulted in a clear win for planning.

"We speculated that moving onto land poured jet fuel on the evolution of the brain as it may have advantaged the hardest cognitive operation there is: Envisioning the future," MacIver said. "It could explain why we can go out for seafood, but seafood can't go out for us."

To test this hypothesis, MacIver and his team developed computational simulations to test the survival rates of prey being actively hunted by a predator under two different decision-making strategies: Habit-based (automatic, such as entering a password that you have memorized) and plan-based (imagining several scenarios and selecting the best one). The team created a simple, open world without visual barriers to simulate an aquatic world. Then, they added objects of varying densities to simulate land.

Survival of the smartest

"When defining complex cognition, we made a distinction between habit-based action and planning," MacIver said. "The important thing about habit is that it is inflexible and outcome independent. That's why you keep entering your old password for a while after changing it. In planning, you have to imagine different futures and choose the best potential outcome."

In the simple aquatic and terrestrial environments examined in the study, survival rate was low both for prey that used habit-based actions and those that had the capability to plan. The same was true of highly packed environments, such as coral reefs and dense rainforests.

"In those simple open or highly packed environments, there is no benefit to planning," MacIver said. "In the open aquatic environments, you just need to run in the opposite direction and hope for the best. While in the highly packed environments, there are only a few paths to take, and you are not able to strategize because you can't see far. In these environments, we found that planning does not improve your chances of survival."

The Goldilocks landscape

When patches of vegetation and topography are interspersed with wide open areas similar to a savanna, however, simulations showed that planning results in a huge survival payoff compared to habit-based movements. Because planning increases the chance of survival, evolution would have selected for the brain circuitry that allowed animals to imagine future scenarios, evaluate them and then enact one.

"With patchy landscapes, there is an interplay of transparent and opaque regions of space and long-range vision, which means that your movement can hide or reveal your presence to an adversary," MacIver said. "Terra firma becomes a chess board. With every movement, you have a chance to unfurl a strategy.

"Interestingly," he noted, "when we split off from life in the trees with chimpanzees nearly seven million years ago and quickly quadrupled in brain size, paleoecology studies point to our having invaded patchy landscapes, similar to those our study highlights, as giving the biggest payoff for strategic thinking."

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Neanderthals practiced close-range hunting 120,000 years ago

Estimated impact angle shown in relation to a standing fallow deer for the hunting lesion observed in the pelvis of an extinct fallow deer killed by Neanderthals 120,000 years ago on a lakeshore close to current-day Halle in Germany.

An international team of scientists reports the oldest unambiguous hunting lesions documented in the history of humankind. The lesions were found on skeletons of two large-sized extinct fallow deer killed by Neandertals about 120,000 years ago around the shores of a small lake (Neumark-Nord 1) near present-day Halle in the eastern part of Germany. The study was led by Professor Sabine Gaudzinski-Windheuser of the Department of Ancient Studies at Johannes Gutenberg University Mainz (JGU) and was now published in the journal Nature Ecology and Evolution.

The study constitutes a significant step forward in our knowledge of the Neandertal niche. It demonstrates how Neandertals obtained their prey, first and foremost in terms of their much debated hunting equipment while also shedding light on their hunting skills.

With an innovative experimental ballistic setup including state-of-the-art motion-sensor technology, the researchers were able to reproduce the specific form of one of the lesions. The results prove the use of a wooden thrusting spear that was impacted with low velocity. This suggests that Neandertals approached animals very closely and thrusted rather than threw their spears at the animals, most likely from an underhand thrusting angle. Such a confrontational way of hunting required careful planning and concealment as well as close cooperation between individual hunters.

The lake where the hunts took place was surrounded by a close canopy forest, a type of environment deemed particularly challenging for hunter-gatherers, even modern human ones. Interestingly, the excavations in the Neumark-Nord area have yielded tens of thousands of bones of large mammals, including red and fallow deer, horses, and bovids, as well as thousands of lithic artefacts from this uniquely rich Last Interglacial lake landscape, attesting to the success of Neandertal survival in forested environments.

"Although hominins most likely started hunting with weapons more than 500,000 years ago, actual evidence on how wooden spear-like objects like those found at Clacton-on-Sea in England as well as in Schöningen and Lehringen in German were used was absent prior to the identification of the Neumark-Nord hunting lesions," stated Gaudzinski-Windheuser. "As far as spear use is concerned, we now finally have the crime scene fitting to the proverbial smoking gun."

From Science Daily