Squirrel poop drops Ice Age clues + The neuroscience of laughter
Summary
Dr. Tyler Murchie discusses how ancient ground squirrel scat from the Yukon permafrost reveals a detailed snapshot of Ice Age ecosystems, including DNA from mammoths and bison. Later, Dr. Sophie Scott explains new research distinguishing between voluntary social laughter and involuntary laughter, showing they originate in different brain networks. The episode highlights how unexpected sources like poop and brain stimulation mapping provide profound insights into history and human behavior.
Topics discussed
Sponsors: Progressive Insurance and Alienware
Introduction: Ancient ground squirrel poop as a data source
Excavating 700,000-year-old burrows in Yukon permafrost
Lab process: Extracting and sequencing ancient DNA
Findings: Ice Age ecosystem snapshot in squirrel scat
Why poop preserves DNA better than sediment
Challenging assumptions: American cheetahs and squirrel species
Environmental DNA and the value of unsuspecting sources
Sponsor: New York Community Trust
Introduction: The neuroscience of voluntary vs. involuntary laughter
Two brain systems: Volitional motor control vs. emotional response
Methodology: Pre-surgical brain mapping and stimulation
The social importance of laughter and closing remarks
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