Sunday, October 22, 2023

 

What do new moms and roaches have in common?


Both undergo amazing transformations to prepare for babies


Peer-Reviewed Publication

UNIVERSITY OF CINCINNATI




Researchers are studying the dramatic physical transformation that some insects undergo to give birth to live young.

This includes suppressing their immune systems to accommodate babies, which is something some insects and people have in common. Understanding how these systems work can help improve treatments for fibromyalgia and other immune disorders.

Biologists at the University of Cincinnati were part of an international team examining the complex structural and physiological changes that take place in Hawaii’s beetle-mimic cockroaches, which give birth to live young.

“It’s not just immunology,” co-author and UC College of Arts and Sciences Professor Joshua Benoit said.

Biologists see similar changes in the insect’s trachea, its immune system and the outer layer of its exoskeleton called a cuticle, which transforms to make room for the babies.

The study was published in the journal iScience.

Cockroach mothers not only incubate their babies until they are the equivalent size of a 2-year-old human toddler, but they also feed them a milk-like nutrient they produce through secretory glands.

Nature has devised a myriad of reproductive strategies across the animal kingdom, said Bertrand Fouks, a postdoctoral fellow at the University of Muenster and the study’s lead author. From birds and reptiles to fish, lots of animals lay eggs. In mammals, egg laying is limited to echidnas, sometimes known as spiny anteaters, and the platypus.

“The beetle-mimic cockroach is one of the rare insects which has developed a complex structure to host the growing embryo similar to placenta in mammals, which made it a perfect model to investigate the evolution of live-birth,” Fouks said.

Beetle-mimic cockroaches have big advantages compared to those that hatch from eggs, Benoit said. Tinier babies that hatch from eggs are exposed to the elements where they’re vulnerable to far more parasites and predators and must immediately find food on their own.

“The class of predators really narrows when you give birth to live young,” Benoit said.

But live births require a far bigger parental commitment.

“It’s a pretty big investment. They can produce 10 juveniles per reproductive cycle compared to 70 to 150 eggs for other roaches,” Benoit said. “So their strategy is to produce fewer higher-quality individuals compared to more individuals with less investment.”

Researchers sequenced the genome of the Pacific beetle-mimic cockroach, the only roach that gives birth to live young. They performed comparative analysis with tsetse flies and aphids, which do likewise, to unravel the genomic basis underlying this transition from laying eggs to birthing babies.

They found that the biological changes that allow beetle mimic cockroaches to give birth to live young are similar to those found in aphids and tsetse flies, demonstrating convergent evolution, Benoit said.

Whether it’s a cow, a lizard or a roach, all undergo remarkably similar urinary and genital organ remodeling, enhanced heart development and altered immunity to accommodate their growing babies, the study found.

Researchers are interested in the link between our immune system and pregnancy. Women are less susceptible to infectious diseases but are far more likely than men to have autoimmune disorders such as lupus.

Benoit said some genes dealing with the immune system are down-regulated (the process of reducing or suppressing a response to a stimulus) during pregnancy. That can explain why some women who suffer from autoimmune disorders might see symptoms go away during pregnancy.

Benoit said they see similar effects in the cockroaches.

“These changes may facilitate structural and physiological changes to accommodate developing young and protect them from the mother’s immune system,” he said.

Study links school redistricting to higher rates of firearm violence in urban communities


In areas that had some type of school redistricting, the firearm incident rate increased almost 11% compared with areas that had no school redistricting


Reports and Proceedings

AMERICAN COLLEGE OF SURGEONS

Infographic School Redistricting & Firearm Violence 

IMAGE: 

ADJUSTMENTS IN SCHOOL BOUNDARIES AND OTHER FORMS OF SCHOOL REDISTRICTING HAVE BEEN LINKED TO SPIKES IN SHOOTING-RELATED INJURIES IN URBAN AREAS, ACCORDING TO NEW STUDY RESULTS BEING PRESENTED AT THE AMERICAN COLLEGE OF SURGEONS (ACS) CLINICAL CONGRESS 2023.

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CREDIT: AMERICAN COLLEGE OF SURGEONS




Key takeaways 

  • This is the first study to examine the impact of school redistricting on firearm violence in urban communities, examining data from 63,000 urban census tracts. 
  • Any school redistricting event was associated with a 10.6% higher firearm incidence rate compared with communities that had no redistricting, and school boundary adjustments were associated with a 21.3% increase. 
  • In areas that had a school redistricting event, firearm violence increased 14% in the year the redistricting occurred over the previous year. 

BOSTON (October 20, 2023): Adjustments in school boundaries and other forms of school redistricting have been linked to spikes in shooting-related injuries in urban areas, according to new study results being presented at the American College of Surgeons (ACS) Clinical Congress 2023. 

Sarabeth Spitzer, MD, MPH, a general surgery resident at Brigham and Women’s Hospital in Boston, presented the study results looking at school redistricting data, firearm injury incident data, and community-level sociodemographic data for 63,000 urban census tracts on a year-to-year basis from 2014 through the 2019-2020 school year. The study used data from the National Center for Education Statistics, Gun Violence Archive, and the American Community Survey.  

Key findings  

  • Among the studied census tracts, 5,665, or 1.5% of all tracts, had some type of school redistricting event.  
  • After adjusting for community characteristics, such as sociodemographic data, any school redistricting was associated with a 10.6% higher firearm incidence rate compared to communities that did not redistrict schools. 
  • School boundary adjustments specifically were associated with a 21.3% increase in firearm injury incidence rate. 

Observations on study results  

While the evidence linking social disruptions and community violence has been well vetted, this is the first study looking at school redistricting specifically, Dr. Spitzer said. Along with the existing evidence surrounding social disruptions, anecdotal evidence from teachers reporting that they noticed a spike in violence in the process of school redistricting provided rationale for the study, she said.  

Dr. Spitzer explained how the study defined school redistricting: “School redistricting, at its most basic level, is when there are changes to where kids go to school based on their home address,” she said. “This happens for various reasons, often due to resource distribution in a community.”  

Different types of redistricting exist, which the study doesn’t specify, but they include combining or rearranging school districts and changing boundaries. 

“Only a few kids are affected, but the resulting impact is that there is social destabilization in some way because, as everyone who has attended middle school and high school knows, you get to know the community that you’re a part of and there are social hierarchies that exist and a known quantity of the people in your area,” she said. “When you have this shuffling of school districts, it means that there are new social interactions and new hierarchies that need to be formed. And you have a disruption as a result of that.” 

These disruptions not only impact children, but parents, as well, who may have to change work routines, and neighbors that families might rely on to watch out for their children, she said. 

The study compared firearm incidents in census tracts for the year a school redistricting event occurred compared with the prior year. “We saw that in the year with a redistricting event, there was a 14% increase in firearm violence compared to the year prior,” Dr. Spitzer said. 

This means policymakers could target resources, such as sending in counselors and expanding training in the ACS STOP THE BLEED® program, to address firearm violence in areas that undergo school redistricting, she added. The ACS STOP THE BLEED® program provides training to anyone to save a life in a bleeding emergency. It has trained more than 3 million people. The ACS operates the program under a license granted by the Department of Defense. 

Dr. Spitzer acknowledged the study data predate the COVID-19 pandemic. “We would love to have more recent data, but, if anything, what we saw in the pandemic was a huge spike in firearm violence,” she said. “We think that part of that is actually due to social destabilization.” Future research, hopefully, would draw on more recent data to investigate the relationship between school redistricting and firearm violence post-pandemic, she said.  

Study coauthors are Tanujit Dey, PhD; Ali Salim, MD, FACS; and Molly P. Jarman, PhD; of Brigham and Women’s Hospital. 

Citation: Spitzer S, et al. School Redistricting’s Impact on Firearm Injury: A Study in Community Disruption, Scientific Forum, American College of Surgeons (ACS) Clinical Congress 2023.  

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About the American College of Surgeons 

The American College of Surgeons is a scientific and educational organization of surgeons that was founded in 1913 to raise the standards of surgical practice and improve the quality of care for all surgical patients. The College is dedicated to the ethical and competent practice of surgery. Its achievements have significantly influenced the course of scientific surgery in America and have established it as an important advocate for all surgical patients. The College has approximately 90,000 members and is the largest organization of surgeons in the world. "FACS" designates that a surgeon is a Fellow of the American College of Surgeons.

 

East Los Angeles program to remove tattoos may help reduce traumatic injuries

By removing tattoos in exchange for community service and science education, the program helps individuals reduce their exposure to violence, build a new identity, and gain employment

Reports and Proceedings

AMERICAN COLLEGE OF SURGEONS

East Los Angeles Program to Remove Tattoos May Help Reduce Traumatic Injuries 

IMAGE: 

DR. DAMON H. CLARK PERFORMS TATTOO REMOVAL ON A CLIENT.

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CREDIT: AMERICAN COLLEGE OF SURGEONS

Key Takeaways 

  • Tattoos, especially those related to gangs and sex work, can make individuals targets for violence. 

  • Tattoos may also make it more difficult for individuals to make changes in their lives, including finding a job or joining the military. 

  • Nearly nine out of 10 of the program’s clients (88%) desired tattoo removal to transition to a healthier life, and more than eight of 10 clients (81%) reported success in achieving their goals after tattoo removal. 

BOSTON (October 20, 2023): Tattoo removal may help to reduce violence and trauma in East Los Angeles, according to study results being presented at the American College of Surgeons (ACS) Clinical Congress 2023. 

Interpersonal violence is a leading cause of traumatic injury in the United States.*  Tattoos identified with gangs or sex work can make individuals a target for violence, according to a study led by Damon H. Clark, MD, FACS, a general surgeon and assistant professor of clinical surgery at Keck School of Medicine of USC in Los Angeles. In addition, disparities in substance abuse, poverty, education, community safety, and employment opportunity underlie individual risk for exposure to violence, the authors note. 

The study showed that removing those tattoos, in exchange for community service and science education, may help these individuals reduce their exposure to violence, build a new identity, and gain employment. Individuals with gang-related tattoos often have a harder time getting jobs or joining the military, which does not allow recruits to have tattoos on certain exposed areas of their bodies, such as face, neck, or hands, Dr. Clark said. Even compared with other American cities, tattoos are a particularly significant part of the Los Angeles culture, he said. 

“Violence can come from rival gang members or even from police, who may act in a more heightened, urgent, and aggressive way when they see someone with a gang tattoo,” Dr. Clark said. “Tattoo removal helps protect individuals and is part of the healing process, helping them get a new identity and job opportunities.” 

Removing the tattoos can help individuals break away from a former life and establish a new identity, helping to prevent relapse, and also may prevent suicide, which is part of the trauma that the program is trying to prevent, Dr. Clark said. 

“A lot of clients who come to get tattoos removed were sex workers,” Dr. Clark said. “They get the tattoo removed to move on with their life emotionally and physically.” 

Removing a tattoo typically costs between $200 and $500 per session. Removing a tattoo done by a professional can require six to eight sessions. However, more than half of the clients get their tattoos from amateurs, often while incarcerated. In prison, for example, tattoo artists use improvised ink, such as paint scrapes, pen ink or pencil lead, and improvised tattoo machines. These tattoos are often more difficult to remove, and may require 15 to 20 sessions, he said. 

The program’s “fee” is for clients to do five hours of community service for each session, which could consist of school attendance, volunteering at a church or non-profit, or attending an Alcoholics Anonymous or Narcotics Anonymous meeting. In addition to Dr. Clark, general surgery residents, emergency department residents, and medical students do the removal procedures. The program, which has just one room and one laser, now has about 300 clients undergoing tattoo removal. 

Besides tattoo removal and community service, the program exposes the clients to education, particularly in science, such as biology and healthcare-related subjects. Sometimes, mentorship and substance use disorder counseling are also provided when appropriate. 

One of the earliest clients of the program, which started in 2016, was a high school dropout when he began getting his gang-related tattoos removed, Dr. Clark said. After going through the program, the client finished high school, attended a four-year college, and is now a Secret Service agent in Washington, D.C. 

“Violence is a medical problem and is a big cost on our country, our hospitals, and our productivity,” Dr. Clark said. “If we treat it as a disease instead of a social problem, we'd be better off.” 

Study details

Surgeons and doctoral students from Keck School of Medicine partnered with Soledad Enrichment Action (SEA) to perform laser tattoo removal in exchange for community service. Clients completed a voluntary, anonymous survey regarding tattoo acquisition and motivation for removal. Medical students and faculty also taught life skills, violence intervention, science, and mindfulness enrichment courses.  

Key findings 

As part of the study, 26 individuals (46% female, 54% male) reported full removal of 35 tattoos after 208 total sessions. Clients performed more than 17,265 hours of community service. 

The researchers found: 

  • 88% of the clients desired tattoo removal to transition to a healthier life.  

  • 81% of the clients reported success in achieving their goals with tattoo removal, including escaping gang affiliation and improving job prospects. 

  • Students of enrichment courses ranked interest in biology 4.5 out of 10 prior to enrichment and 8.6 after.  

Other study authors include Helena Bugacov, PhD, and Anaar E. Siletz, MD, PhD, Keck School of Medicine, and Michael Massa, EdD, Central Juvenile Hall High School. 

The study authors have no disclosures. 

Citation: Clark DH, et al. A Multipronged Approach to Primary Prevention of Trauma in East Los Angeles, Scientific Forum, American College of Surgeons (ACS) Clinical Congress 2023. 


A client's neck tattoo before treatment.

________________________  

* Sumner SA, Mercy JA, Dahlberg LL, Hillis SD, Klevens J, Houry D. Violence in the United States. JAMA. 2015;314: 478.  

# # # 

About the American College of Surgeons 

The American College of Surgeons is a scientific and educational organization of surgeons that was founded in 1913 to raise the standards of surgical practice and improve the quality of care for all surgical patients. The College is dedicated to the ethical and competent practice of surgery. Its achievements have significantly influenced the course of scientific surgery in America and have established it as an important advocate for all surgical patients. The College has approximately 90,000 members and is the largest organization of surgeons in the world. “FACS” designates that a surgeon is a Fellow of the American College of Surgeons.

 

Reliable patient education materials on breast cancer are difficult to access


Research reveals that many educational materials have a negative tone and may not adequately address the unique needs of breast cancer patients


Reports and Proceedings

AMERICAN COLLEGE OF SURGEONS




Key Takeaways 

  • Women with breast cancer, who are making complex decisions about treatment options during an already stressful time, may turn to the wide variety of materials available online, which are not always from data-driven sources. 

  • Researchers found that educational materials often vary in quality, can have a negative tone, and are written above the sixth-grade reading level recommended by the National Institutes of Health. 

BOSTON (October 20, 2023): Women with breast cancer must often make complex decisions about surgery and treatment options during an already stressful time in their lives, and many of these women may turn to the wide variety of materials available online. New research presented at the American College of Surgeons (ACS) Clinical Congress 2023 has found that reliable educational materials about breast surgery are not only difficult to assess but are also presented at much higher reading levels than recommended. 

Two studies, presented at the Scientific Forum of the annual ACS Clinical Congress, held in Boston, Massachusetts, October 22-25, shed light on the need to develop more accessible materials for women with breast cancer, which is the most common non-skin cancer diagnosed in women in the United States. 

“In breast surgery, there are a lot of decisions patients have to make, and sometimes giving a choice to a patient can be really overwhelming, especially if there’s not a one-size-fits-all solution,” said co-author Emily Palmquist, MD, a breast surgeon at the University of Washington Medical Center and an assistant professor in the department of general surgery at the University of Washington School of Medicine. “As much as we as surgeons try to educate patients, there is limited time and patients can only absorb so much in a visit. Some patients may turn to other resources online, such as blogs and non-validated sources that they may find easier to read and understand, which raises concern about the accuracy of materials patients may be accessing.” 

Dr. Palmquist was part of a group of researchers from the University of Washington who reviewed English-language patient education materials describing breast-conserving surgery, mastectomy, and lymph node surgery from National Cancer Institute-designated Comprehensive Cancer Center (NCI-CCC) websites. Readability was assessed using five validated assessment scales: the Flesch-Kincaid Grade Level, Gunning-Fog Index, Coleman-Liau Index, Simple Measures of Gobbledygook Index, and Automated Readability Index. These validated scales use parameters such as word count and sentence difficulty to assess readability.  

The team found that patient education materials were publicly available on 78% of NCI-CCC websites, but the average readability score of these materials – defined as the grade level required to understand the written content – was 11.6 (range 10.1-13.9) across five scales, which is higher than National Institutes of Health (NIH) recommendations and also above national literacy levels in the U.S., where 19% of U.S. adults possess low literacy skills

“Breast surgeons are often one of the first providers that patients meet when they are diagnosed. Even if we do a fantastic job at patient education in our eyes, patients often return home not having asked the questions that they might have asked when they were in a more comfortable environment,” said first author Sarah Brennan, a fourth-year medical student at the University of Washington. Brennan was inspired to lead the project after rotating at a large county hospital in Washington that treated many vulnerable patients. 

“Many patients may turn to the wide variety of resources available online. I think these findings highlight the importance of making sure the resources that are coming from cancer centers are meeting the needs of patients,” she said. 

Study coauthors include Claire L. Buchanan, MD, FACS; Kristine E. Calhoun, MD, FACS; Sara H. Javid, MD, FACS; and Meghan R. Flanagan, MD, FACS. 

Evaluating the Vast Landscape of Online Materials 

In another study that will also be presented at the Scientific Forum, researchers from Crozer-Chester Medical Center in Upland, Pennsylvania, evaluated the wide variety of materials available online about breast surgery from accredited organizations or foundations. 

The researchers input the search phrase “breast cancer surgery” and “mastectomy” into the three most popular search engines (Google, Yahoo, Bing) and analyzed 108 unique resources for 1) readability, 2) bias, 3) quality, and 4) tone using validated tools that help analyze the quality and tone of information as well as the overall reading level. 

The researchers found that most website content exceeded the recommended sixth-grade reading level (most were on average at the 10th grade reading level) and had information deemed either of fair or poor quality, with websites on breast cancer surgery scoring below average for quality evaluation. At least 2-3 sentences per website had stigmatizing language. 

“In addition, most of the tones that were prominent were negative in character. Fear, analytical, tentative, and sadness were the four most prominent tones,” said lead author Praveen Satarasinghe, MD, MBA, a third-year resident physician in general surgery at Crozer-Chester Medical Center. Dr. Satarasinghe leveraged his background in data analytics to design the research study. 

“It’s surprising that for such a delicate topic like breast cancer, the first piece of information a patient may see online is filled with a negative tone,” he added. “In the future, it will be interesting to see how we can shift the resources to capture a positive tone to impact patients who want to seek treatment for breast cancer. I think by going into the details, we can see that there’s clearly a problem that needs to be addressed.” 

“This study highlights the need to provide educational services on a more accessible level for all patients,” added senior author Chantal Reyna, MD, FACS, FSSO, section chief of breast surgical oncology at Loyola University in Chicago. Dr. Reyna previously served as chief of breast surgery and medical director of the Crozer Health Breast Program. “Our focus needs to be on making sure that there is ease of readability in the materials we hand out, and that the tone of the materials doesn’t enhance that fear that many patients may experience in an already stressful time.” 

Study coauthors include Daniel Kim, MD and Jandie Posner, DO. 

Citations:  

  • Brennan S, et al. Breast Surgery Patient Education Materials: Who Are We Educating?, Scientific Forum, American College of Surgeons (ACS) Clinical Congress 2023.  

  • Satarasinghe P, et al. Evaluating Online Information about Breast Cancer Surgery to Improve Quality, Scientific Forum, American College of Surgeons (ACS) Clinical Congress 2023.  

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About the American College of Surgeons 

The American College of Surgeons is a scientific and educational organization of surgeons that was founded in 1913 to raise the standards of surgical practice and improve the quality of care for all surgical patients. The College is dedicated to the ethical and competent practice of surgery. Its achievements have significantly influenced the course of scientific surgery in America and have established it as an important advocate for all surgical patients. The College has approximately 90,000 members and is the largest organization of surgeons in the world. “FACS” designates that a surgeon is a Fellow of the American College of Surgeons.

 

COVID-19-related jail decarceration did not affect crime in California


Peer-Reviewed Publication

CRIME AND JUSTICE RESEARCH ALLIANCE




Since 2011, California has significantly reformed its criminal justice system, reducing the size of its prison population, with no effect on violent crime and only marginal impacts on property crime statewide. The COVID-19 pandemic furthered decarceration as the state reduced state prison and jail populations to slow the spread of the virus. Concerns emerged that releases under the auspices of COVID mitigation harmed public safety. A new study explored this notion and found no consistent relation between COVID-19-related jail decarceration and violent or property crime at the county level in the state.

The study, by researchers at the University of California (UC) Irvine and the University of Arizona, is published in the Journal of Contemporary Criminal Justice. Their work is promoted by the Crime and Justice Research Alliance, which is funded by the National Criminal Justice Association.

            “California’s efforts to reduce overcrowding as a way to limit the spread of COVID-19 reduced the correctional population more severely and abruptly than any of the state’s previous decarceration reforms,” according to Charis E. Kubrin, professor of criminology, law, and society at UC Irvine, who led the study. “Concerns about what impact these actions would have on crime rates were widespread, and although violent and property crime in large cities declined during the pandemic, homicide and car theft rose significantly.”

            Because these increases mirrored national trends, it was unclear whether California’s pandemic-related decarceration efforts were responsible. In this study, researchers sought to determine whether COVID-19 jail downsizing measures were related to crime trends in the state, estimating the effect of the measure on crime in the state’s 58 counties and isolating the impact of decarceration on crime from other shocks affecting the state as a whole. They examined monthly average daily jail population counts from January 2013 to December 2021, and county-level monthly crime data during the same period; COVID-19 decarceration occurred from January through December 2020.

            The study did not find a consistent relation between COVID-19 jail decarceration and crime at the county level, suggesting that downsizing, on average, did not drive crime increases statewide.

            Among the study’s limitations, the authors note that because they used a synthetic control adaptation, the treated and synthetic series did not reflect the fully treated and completely untreated versions of county crime rates that are generally produced via synthetic controls. The authors also note they measured COVID-19 mitigation efforts only from March through December 2020—a relatively short period—in order to minimize the effects of crime associated with summer 2020 protests following the murders of Breonna Taylor, George Floyd, Jacob Blake, and others.

            “These limitations reveal how challenging it is to identify decarceration’s potential effect from any one factor during one of the most dynamic and challenging periods the state, as well as the country as a whole, experienced,” notes Bradley J. Bartos, assistant professor of government and public policy at the University of Arizona, who coauthored the study. “Nonetheless, our findings offer insights that can inform future criminal justice innovations.”

 

Challenging prehistoric gender roles: Research finds that women were hunters, too


Team discovered little evidence to support the idea that roles were assigned specifically to each sex


Peer-Reviewed Publication

UNIVERSITY OF DELAWARE



It’s a familiar story to many of us: In prehistoric times, men were hunters and women were gatherers. Women were not physically capable of hunting because their anatomy was different from men. And because men were hunters, they drove human evolution.

But that story’s not true, according to research by University of Delaware anthropology professor Sarah Lacy, which was recently published in Scientific American and in two papers in the journal American Anthropologist

Lacy and her colleague Cara Ocobock from the University of Notre Dame examined the division of labor according to sex during the Paleolithic era, approximately 2.5 million to 12,000 years ago. Through a review of current archaeological evidence and literature, they found little evidence to support the idea that roles were assigned specifically to each sex. The team also looked at female physiology and found that women were not only physically capable of being hunters, but that there is little evidence to support that they were not hunting.

Lacy is a biological anthropologist who studies the health of early humans, and Ocobock is a physiologist who makes analogies between modern day and the fossil record. Friends in graduate school, they collaborated after “complaining about a number of papers that had come out that used this default null hypothesis that cavemen had strong gendered division of labor, the males hunt, females gather things. We were like, ‘Why is that the default? We have so much evidence that that's not the case,’” Lacy said.

The researchers found examples of equality for both sexes in ancient tools, diet, art, burials and anatomy. 

“People found things in the past and they just automatically gendered them male and didn't acknowledge the fact that everyone we found in the past has these markers, whether in their bones or in stone tools that are being placed in their burials. We can't really tell who made what, right? We can't say, ‘Oh, only males flintknap,’ because there's no signature left on the stone tool that tells us who made it,” Lacy said, referring to the method by which stone tools were made. “But from what evidence we do have, there appears to be almost no sex differences in roles.” 

The team also examined the question of whether anatomical and physiological differences between men and women prevented women from hunting. They found that men have an advantage over women in activities requiring speed and power, such as sprinting and throwing, but that women have an advantage over men in activities requiring endurance, such as running. Both sets of activities were essential to hunting in ancient times.

The team highlighted the role of the hormone estrogen, which is more prominent in women than men, as a key component in conferring that advantage. Estrogen can increase fat metabolism, which gives muscles a longer-lasting energy source and can regulate muscle breakdown, preventing muscles from wearing down. Scientists have traced estrogen receptors, proteins that direct the hormone to the right place in the body, back to 600 million years ago

“When we take a deeper look at the anatomy and the modern physiology and then actually look at the skeletal remains of ancient people, there's no difference in trauma patterns between males and females, because they're doing the same activities,” Lacy said.

During the Paleolithic era, most people lived in small groups. To Lacy, the idea that only part of the group would hunt didn’t make sense. 

“You live in such a small society. You have to be really, really flexible,” she said. “Everyone has to be able to pick up any role at any time. It just seems like the obvious thing, but people weren't taking it that way.” 

Man the Hunter

The theory of men as hunters and women as gatherers first gained notoriety in 1968, when anthropologists Richard B. Lee and Irven DeVore published Man the Hunter, a collection of scholarly papers presented at a symposium in 1966. The authors made the case that hunting advanced human evolution by adding meat to prehistoric diets, contributing to the growth of bigger brains, compared to our primate cousins. The authors assumed all hunters were male. 

Lacy points to that gender bias by previous scholars as a reason why the concept became widely accepted in academia, eventually spreading to popular culture. Television cartoons, feature films, museum exhibits and textbooks reinforced the idea. When female scholars published research to the contrary, their work was largely ignored or devalued.

“There were women who were publishing about this in the ’70s, ’80s and ’90s, but their work kept getting relegated to, ‘Oh, that's a feminist critique or a feminist approach,’” Lacy said. “This was before any of the work on genetics and a lot of the work on physiology and the role of estrogen had come out. We wanted to both lift back up the arguments that they had already made and add to it all the new stuff.” 

Lacy said the “man the hunter” theory continues to influence the discipline. While she acknowledges that much more research needs to be done about the lives of prehistoric people — especially women — she hopes her view that labor was divided among both sexes will become the default approach for research in the future. 

For 3 million years, males and females both participated in subsistence gathering for their communities, and dependence on meat and hunting was driven by both sexes, Lacy said.

“It's not something that only men did and that therefore male behavior drove evolution,” she said. “What we take as de facto gender roles today are not inherent, do not characterize our ancestors. We were a very egalitarian species for millions of years in many ways.”