| NSF Org: |
SMA SBE Office of Multidisciplinary Activities |
| Recipient: |
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| Initial Amendment Date: | July 27, 2019 |
| Latest Amendment Date: | September 3, 2020 |
| Award Number: | 1911857 |
| Award Instrument: | Fellowship Award |
| Program Manager: |
Josie Welkom Miranda
jwmirand@nsf.gov (703)292-7376 SMA SBE Office of Multidisciplinary Activities SBE Directorate for Social, Behavioral and Economic Sciences |
| Start Date: | September 15, 2019 |
| End Date: | February 28, 2022 (Estimated) |
| Total Intended Award Amount: | $148,000.00 |
| Total Awarded Amount to Date: | $175,000.00 |
| Funds Obligated to Date: |
FY 2020 = $27,000.00 |
| History of Investigator: |
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| Recipient Sponsored Research Office: |
Sherman Oaks CA US 91403-2708 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
Los Angeles CA US 90095-8353 |
| Primary Place of
Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): |
(SPRF-FR) SBE Postdoctoral Res, Biological Anthropology, COVID Impacts on Exisiting Act |
| Primary Program Source: |
01002021DB NSF RESEARCH & RELATED ACTIVIT |
| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.075 |
ABSTRACT
This award was provided as part of NSF's Social, Behavioral and Economic Sciences (SBE) Postdoctoral Research Fellowships (SPRF) program and SBE's Biological Anthropology program. The goal of the SPRF program is to prepare promising, early career doctoral-level scientists for scientific careers in academia, industry or private sector, and government. SPRF awards involve two years of training under the sponsorship of established scientists and encourage Postdoctoral Fellows to perform independent research. NSF seeks to promote the participation of scientists from all segments of the scientific community, including those from underrepresented groups, in its research programs and activities; the postdoctoral period is considered to be an important level of professional development in attaining this goal. Each Postdoctoral Fellow must address important scientific questions that advance their respective disciplinary fields. Under the sponsorship of Dr. Jerome Siegel at the University of California, Los Angeles, this postdoctoral fellowship award supports an early career scientist investigating sleep patterns in a modern hunter-gatherer population. Most people find it impossible to start their day without an alarm clock and a cup of coffee, but San hunter-gatherers do not have such amenities. During human evolution, early humans needed to figure out what time they needed to wake up each day and go to sleep each night in order to maximize their reproductive success in the context of a traditional hunter-gatherer lifestyle. The San population lives a similar lifestyle today, with most plant food being collected from wild sources, and all meat coming from hunting wild animals with bow-and-arrow. They live in a remote village where they do not have access to electricity or running water. People spend almost all of their time outside, including sleeping outside, except for when rain is expected.
Earlier work in this and two other similar populations found that sleep duration is 5.7-7.1 hours per night, similar to the typical sleep duration observed in the United States. Sleep is normally initiated several hours after sunset and terminated at the coldest time of the 24-hour day. People sleep one hour longer per night in the winter months than they do in the summer months. These similarities in sleep patterns across three independent populations may be driven by biological adaptations to the natural environment. The follow-up research in this fellowship investigates how ambient conditions affect sleep within the San population. Changes in sleep timing and duration across the year, measured with wrist-worn accelerometers, can be analyzed in tandem with weather data to assess the relative influence of light and temperature on sleep. In addition, using portable EEG monitors, the distribution of REM and non-REM across the night can be assessed and compared between the summer and winter months, when sleep duration differs by about one hour per night. This research will identify the importance of temperature as a predictor of human sleep conditions, and begin to explain why sleep varies across the year in hunter-gatherer populations. These insights are important to better identify how our evolved sleep biology clashes with modern Western conditions, and how that clash may increase the risk of various sleep pathologies. They are also important first steps towards better understanding some of the adaptive challenges that faced early human ancestors as they transitioned from sleeping in trees in tropical climates, like chimpanzees, to the patterns of sleep conditions seen today.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
The Covid-19 pandemic significantly affected the timeline and execution plan for this project; however, Dr. Gandhi Yetish has utilized the award period to engage in productive enterprise in several areas of professional development and still ensure that all research goals are met, albeit approximately 1 year later than initially planned.
Dr. Yetish was able to pivot from performing a study of seasonal sleep in the San hunter-gatherer population of Namibia, which was inaccessible due to Covid-related travel restrictions and safety concerns during the award period, to performing a study of seasonal sleep in the Hadza hunter-gatherer population of Tanzania. This new Hadza data is being analyzed in tandem with limited San data collected from before the award period began so as to best achieve the stated research goals: determining the relative influence of light and temperature in predicting seasonal changes in sleep timing and duration in 2 hunter-gatherer populations living at different latitudes.
He is recording sleep and light with wrist-worn accelerometers (Actiwatch Classics, professional grade devices similar to FitBit), and using several professional grade temperature loggers (Loggernet, Elitech, and Kestrel instruments) to record ambient local weather in Hadza camps in Tanzania.
During the award period, Dr. Yetish became functionally fluent in Swahili at the MS-TCDC school in Usa River, Tanzania. He also trained in Wilderness First Responder skills from the NOLS program to provide any necessary emergency medical intervention during fieldwork in Tanzania.
During the Covid-19 lockdown, when fieldwork was not possible, Dr. Yetish spent extensive time assembling a portfolio of teaching materials to add to his job application package for tenure-track positions. He also invested in career development and learning advanced research methods: professional academic training from the National Center for Faculty Development and Diversity, advanced personal knowledge management from Building a Second Brain, and job search and application skills from the Cheeky Scientist Association.
He also spent considerable time outlining and drafting manuscripts which are currently scheduled to be submitted for publication in 2022. The first manuscript is about the effect of the nighttime sleep environment on sleep timing and nighttime interruptions among Tsimane horticulturalists in Bolivia. The second is about the relationship between reaction time and sleep duration across the year among San hunter-gatherers in Namibia.
Once fieldwork became possible, Dr. Yetish launched a year-long recording of seasonal sleep among Hadza hunter-gatherers in Tanzania. That project is ongoing, and scheduled to finish by February 2023. Dr. Yetish will be supported by Dr. Jerome Siegel of UCLA and his NIH award to complete this data collection protocol, and perform the subsequent analyses and publications.
Conducting this project has been a significant undertaking, especially in the post-Covid era, but is expected to produce numerous insights into the seasonal dynamics of sleep in a small-scale population of contemporary hunter-gatherers. It has also positioned Dr. Yetish to advance to the next stage of his career, equipped with new skills and insights to inform and enhance his own developing research trajectory.
Last Modified: 07/28/2022
Modified by: Gandhi Yetish
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