Reindeer Herder Total Energy Expenditure…Reindeer Herders Work Hard!

I am excited to share our new publication about Reindeer Herder total energy expenditure (TEE, kcal/day)! This work is the result of a collaboration with Dr. Päivi Soppela, Dr. Minna Turunen, Ville Stenbäck, Dr. Karl-Heinz Herzig, Dr. Rebecca Rimbach, and Dr. Herman Pontzer. We measured how many calories the reindeer herders in sub-Arctic Finland expend and consumed during an exceptionally busy time of year…the autumn herd roundup. We also included some pilot data from a much less busy time in the spring.

The herd round up consists of collecting reindeer from their summer pastures either on foot or with the aid of all-terrain vehicles, motorbikes, snowmobiles, or helicopters. During this time, herders count the number of reindeer, separate the animals to be left alive from those to be slaughtered, mark calves with the owner’s earmarks, and return any wayward reindeer to their proper owners.

A picture of the 2019 autumn herd round up. Photo taken by Dr. Minna Turunen.

Here are some of the key findings:

Herders are very active during the annual herd roundup!

We measured TEE using two methods: the gold standard doubly labeled water technique and the flex-heart rate method. During the herd roundup, herders expended a mean of 4183 ± 949 kcal/day with female TEE ranging from 2898-3887 kcal/day and male TEE ranging from 3463-5853 kcal/day. There was no significant difference between the two methods.

Herder total energy expenditure by sex and measurement method

Herders eat way fewer calories than they burn during the roundup, and their diet is relatively high in fat.

Females consumed 883-2195 kcal/day and males consumed from 854-3638 kcal/day, which is well under the number of calories they were burning each day. Diet information was collected via diet diaries, and this can be a rather inaccurate estimate of calories consumed. However, even if herders underreported calories by as much as 20%, they still would have expended ~1000 kcal more than they were consuming each day during the herd roundup. The herders’ diet consisted of a greater proportion of protein and fat than is recommended by the World Health Organization (WHO).

Herder diet composition (right) compared to WHO recommendations (left)

Herders expend a similar number of calories to farming economy populations like the Aymara speaking peoples and Shuar…at least during the herd roundup.

We compared the herder total energy expenditure to that of hunter-gatherers, farming economy populations, and market economy populations. Herder TEE was significantly higher than hunter gatherer and market economy populations, but very similar to that of the farming populations. However, herder TEE was much lower during the spring pilot study, though May is a particularly less busy time of the herder year.

Log TEE vs. Log Body Mass Regression. The herd roundup is represented in bold red and the herder spring pilot study in bold black.
TEE residuals for each of the comparative populations

Given exposure to extreme cold in addition to high physical activity levels, one might expect herder TEE to be significantly higher than, rather than equivalent to, equatorial farming economy populations with similar activity levels but a potentially reduced thermoregulatory burden. There are several potential explanations for the similar energy expenditure among the herders and the farming economy populations, all of which highlight how local ecologies and biologies likely play an important role in shaping energy expenditure.

  1. Herders are very good and very experienced at mitigating cold stress – using technology, alternating tasks, and eating warming foods, for example.
  2. The herders’ high levels of physical activity may help reduce the cost of trying to stay warm in their cold climate.
  3. The farming economy populations are also known to carry a high parasitic burden (though cold climate populations have their fair share of such burdens, too, though not to the degree of equatorial populations). This high parasitic burden can raise energy expenditure in the way that the need to keep warm may raise energy expenditure among the herders.

What’s Next?

Well, we are applying for funding in hopes of expanding TEE measurements across seasons to get a better, more detailed view of energy expenditure across the herder work year. We would also like to expand the number of participants, and begin to look at the impact of climate change on reindeer herder TEE and other physiological measures.

Sexism in Sports

I recently had two articles come out in Sapiens revolving around the theme of sexism in sports. The first article tackles some of the myths and misconceptions regarding sex differences in athletic performance. The second article takes a look at how sexism is still prevalent in the Olympic Games with a particular focus on natural testosterone level policing among some women athletes and briefly touches on trans-athlete inclusion.

Both of these articles were born out of my experience researching and teaching exercise physiology and the anthropology of sports. And both of these articles attracted some less than pleasant and incredibly misinformed responses.

Responses to the sex differences articles ranged from genuine curiosity and a place from wanting to learn to outright calling me a liar. Many struggle to accept that testosterone is not the end all be all of sports performance. Others cannot fathom that women may potentially have an athletic advantage in some sports. I think what frustrates me the most with these responses is that many of these folks seem to have not fully read the article nor attempt to read the extensive supporting information provided in text.

Furthermore, one of the critical points of this article was that women are woefully underrepresented in exercise physiology research both as research participants and researchers. I state clearly that everything we currently know about women’s athletic performance could be wrong as the current research just isn’t there to make many solid claims . Pushing the physiological work aside for a moment, it is also incredibly difficult to determine if the advantages men do have are actually due to better performance capability or just better opportunity, training, and exposure at a young age – a topic I did not have time to go into with this article.

As for the second article, current responses seem to come from those who are anti-trans inclusion in sports. They claim that it is unfair for trans athletes (particularly trans women) to compete with cis-gendered athletes. One individual responded to my article by linking to this twitter post claiming that Laurel Hubbard (trans-woman athletes competing in Olympic Weightlifting for New Zealand) knocked Nini Manumua out from Olympic competition. However, if this commenter had scrolled just a little further down that thread, she would have seen a strong argument that Manumua would have struggled to qualify regardless of Hubbard’s success. This is equivalent of saying “If the other team didn’t score so many points, we would have one!”

There is also the argument that there are only two distinct biological sexes. This is just patently wrong. You can have a read of this wonderful article lead by Zachary DuBois.

These and other anti-trans athlete arguments are false alarms. You can read why in my article linked above. Or here. Or listen to it here. The idea that trans-gender women are going to dominate sports is not based in reality, it is based in fear and bias.

I also highly recommend a couple of films for folks who may not want to read some of the articles but would like to hear from the trans-athlete perspective: Transformer and Changing the Game.

Dare To Be Human

I recently had the opportunity to be on the Dare To Be Human podcast that is hosted by Kat Koppett and Livia Walker who I was fortunate enough to get to know and befriend during my time in Albany, NY. They are a part of the Mop Co Improv Theatre, where my husband did improv for almost three years. They were also essential to the improv and anxiety study I conducted with colleagues.

I thought this interview was going to revolve entirely around that study, but it didn’t! It was perhaps one of the most wonderfully wide-ranging interviews I have ever been a part of. I touch on a number of topics that are near and dear to my heart, and I am so grateful to Kat and Livia for giving me the time and space to discuss them.

Have a listen here – I hope you enjoy!

Rock and a Cold Place: Neanderthal Biocultural Cold Adaptations

Comparison of a female Neanderthal to a female anatomically modern human. Illustration by Morgan Zepf

My review paper on Neanderthal biocultural adaptation to cold (email me for a copy), written with the amazing Dr. Sarah Lacy and Alexandra Niclou, came out today!

This paper was born out of a poster (link to file below) I and Alex made for a special American Association of Physical Anthropology poster session held to celebrate Dr. Erik Trinkaus‘ career. It was a wonderful session that gathered together all of his students.

A picture of Dr. Erik Trinkaus and many of his students. A truly wonderful celebration of his career and impact on the field.

For this poster, we wanted to talk about the different mechanisms that may have been utilized by Neanderthals to survive and thrive in cold climates. While making this poster, we realized that there was no paper that brought together the anatomical, physiological, and cultural evidence of Neanderthal cold climate adaptations. So, we decided to write one! We brought my friend, colleague Sarah Lacy in on this as Neanderthals are her area of expertise, and we got to work!

This paper puts in one place the variety of different cold climate adaptations Neanderthals may have had. Furthermore, we identify ten different areas we think should be the focus of future research.

I adore this paper for many reasons:
1. This paper provided the opportunity to collaborate and write with two brilliant women who I adore. Writing with them was a joy, and we worked incredibly well together.
2. The the image of Neanderthals and Anatomically Modern Humans depicts females…such a rare thing. This figure was also drawn by an undergraduate student of mine, Morgan Zepf.
3. It has an awesome reference list! The original draft had 275 references, but had to cut that down to 100 to fit the journal guidelines.
4. This will be a great paper to use in undergraduate classes!
5. We hope this paper will guide and inspire future dissertations.
6. I started writing this review on my Spring Break 2020 where I went to a cabin in the middle of no where and just wrote. When I emerged from this writing retreat, the entire world had gone on lock down due to the COVID-19 pandemic. This paper will always hold an odd place in my memory because of that.

Encouraging Creativity, Critical Thinking, & Transferrable Skills

I have a new paper out in the Teaching and Learning Anthropology Journal!

In this article, I discuss why I have my students do creative assignments – they encourage students to think critically and deeply about a topic, they learn how to communicate across a variety of platforms, and they develop highly sought after transferrable skills. I present two assignments: Evolutionary Forces Infographic and Primate Podcast/YouTube Video. For each, I provide details on assignment goals, guidelines, resources, and assessment.

I also present examples of student work (with their permission, of course) and potential assignment modifications. However, I must say, it delights me beyond belief to be able to highlight the excellent work my students have done. Their receptivity of these unusual assignments is key to success and key to their learning.

You can find more creative assignments and examples of student work here.

American Journal of Human Biology Editor’s Choice

As I have posted about the article before, I won’t go into details, you can find those here. However, I am delighted and proud to share that my article with collaborators Dr. Minna Turunen, Dr. Päivi Soppela, Ville Stenbäck, and Dr. Karl-Heinz Herzig was selected as the Editor’s Choice article for the 32(6) issue of the American Journal of Human Biology.

A photo Minna took was also selected to be the issue cover photo!

COVID-19 Impact on Gym Lifters

This was our recruitment poster

Back in May during one of the many peaks of the COVID-19 pandemic and stay at home orders, I was feeling useless. I felt the need to contribute and help. I also was personally feeling terrible since I wasn’t able to maintain my powerlifting routine. I decided to combine the two.

I got in touch with my friend and colleague, Dr. Katie Rose Hejtmanek, and we put together an online survey looking at gathering information on how the stay at home orders affected exercise routines. Furthermore, we wanted to find out how the changes in routine also affected perceived physical and mental well being.

We quickly got over 500 survey respondents, and it became very clear that folks who almost exclusively used gyms before the pandemic faired the worst during the stay at home orders. We have not published these results yet, but wanted to put something together in hopes of getting results back as quickly as possible to out participants as well as providing some techniques for coping.

Here is the infographic we created based on the preliminary analysis.

Thanks to all who participated!

Organized Adult Play and Stress Reduction: Testing the Absorption Hypothesis in a Comedy Improv Theater

Published in: Adaptive Human Behavior and Physiology, Published online 18 September 2020

https://link.springer.com/article/10.1007/s40750-020-00147-z

Can the stress relieving aspects of going to church be replaced by joining another type of group activity involving belief, training, and focus? A team led by Notre Dame anthropologist Cara Ocobock tested the “absorption hypothesis” in two comedy improv troupes at a theater in upstate New York.

Improv comedy requires a dedicated group of people who practice multiple times a week for performances and have the focus and fleetness of mind to riff together on themes that amuse and provoke live audiences. The study was inspired by Ocobock’s husband, a member of one of the troupes, and previous work by University of Alabama co-author Christopher Lynn. Lynn had studied Pentecostals congregations in upstate New York and found members with more experience speaking in tongues had generally lower stress.

The improv study is exploratory because they had a limited number of participants, but their goal was to combine Lynn’s previous approach with one taken from another anthropologist, Stanford’s Tanya Luhrmann, who has studied other Christian Charismatics (Charismatic religion refers to manifestations of “gifts” from God, such as speaking in tongues, which involves God speaking through a person). 

Luhrmann coined the “absorption hypothesis” in her work, suggesting that Charismatics who are most successful at talking with God share a belief that they can, practice or train to do so, and have a better than average ability to become psychologically absorbed in the process.

In non-religious behavior, group play behaviors are known to be highly absorptive as well, and have the potential to reduce distress and anxiety. As such, Ocobock and Lynn designed this study in collaboration with the improv players, many of whom believe improv practices help them alleviate anxiety in their daily lives. Study team members Mallika Sarma and Lee Gettler, also from Notre Dame, conducted the analysis of saliva samples collected in a rigorous protocol over performance, rehearsal, and non-improv days.

The amount of improv experience (though the range of experience was limited in this study) was not a factor, suggesting that comedy improv is not quite analogous to active church membership. However, improvisors may experience stress reduction associated with the absorption involved in adult play.

New grant!

I and my colleagues, Drs. Scott Maddux and Libby Cowgill, have just been awarded an NSF collaborative grant for our project “Experimental testing of thermoregulatory principles: Re-evaluating ecogeographic rules in living humans“.

We will be building a climate chamber down at UNTHSC over the next year, and then begin collecting data. Below is the public abstract for our project.

Human anatomy varies widely around the world but claims that certain physical features are beneficial in particular climates have rarely been experimentally tested. This research will evaluate how differences in head, trunk, and limb anatomy influence the ability of human subjects to regulate their internal body temperature when exposed to different climatic conditions in an environmental test chamber. This collaborative project will thus experimentally test long-held assumptions regarding climatic patterning of human body form. The investigators will share the results of this project through academic publications, STEM outreach activities, public talks, and interviews on a nationally recognized podcast. Graduate, undergraduate, and medical students will be trained in data collection and analysis through participation in this research, and field trip demonstrations of the project equipment and methods will be used to expose economically disadvantaged Texas high school students to potential careers in science and medicine. This project will also produce high-quality, whole body CT scans which will be made readily available to other researchers through an online data archive. Finally, this research will shed light on issues important to both the broader scientific community and the general public, including the significance of human biological diversity and the potential implications of global climate change.

This research will experimentally test proposed relationships between thermoregulatory benefits and environmentally-patterned variation in human anatomy. While climatic pressures are widely cited as contributing to global variation in human head shape, torso dimensions, limb proportions, and overall body size, specific links between physical features and body function in different climatic conditions have not been experimentally established. Furthermore, studies of adaptation to climate have historically focused on separate regions of the body (e.g. braincase, nose, torso, upper limb, lower limb), with minimal attention to how these different anatomical structures interact with one another to function as a whole. To remedy this, the research uses state-of-the-art technologies, including computed tomography imaging and an environmental chamber, to measure the physiological responses of physically diverse living participants exposed to controlled environmental conditions simulating three global climate extremes (hot-dry, hot-humid, cold-dry). Validation of proposed thermoregulatory benefits of specific body forms is essential for guiding future research on climatic adaptation. Further, by employing a
whole-body approach, this study will clarify the role of different anatomical regions in overall thermoregulatory function. In sum, this study will explicitly link hard and soft tissue morphology to physiological outcomes, permitting more confident assessment of climatic adaptation in both modern populations and the fossil record.