Pnas Science Sessions

Bo Wang and Chunpeng Xu describe how fossilized katydids provide insight into the role of insect sounds in the Mesozoic.

Tom McGrath describes how the neural network AlphaZero taught itself how to play chess without observing a human game.

Orit Peleg, Golnar Fard and Francisco López Jiménez explain how honeybees overcome geometric constraints to construct honeycombs.

Taylor Hersh explores how patterns of clicks produced by sperm whales suggest the exchange of cultural information between the whales.

Researchers discuss what animal soundscapes can tell us about the health of ecosystems.

Daniel Cusworth discusses combining aircraft-based and satellite-based measurement to identify methane emission point sources.

Syee Weldeab describes what researchers can learn from ancient global warming about the risks posed by ocean floor methane hydrates.

Ling Zhu and David B. Grusky explore intergenerational factors influencing occupational gender segregation in the United States.

Izzy Gainsburg and Veronica Derricks discuss how patient activation can disrupt implicit bias in physician-patient interactions.

Matilda Gibbons, Lars Chittka and Jonathan Birch discuss the possibility that bumblebees may feel pain.

Researchers explore how misinformation spreads and what can be done to stop it.

Lauren Howe and Alia Crum explore the interactions of societal biases with the placebo effect.

Steve Horvath and Elaine Ostrander explain the usefulness of epigenetic clocks in humans and dogs.

Researchers explore how and when humans first arrived in the Americas.

L. Mahadevan, Petur Bryde, and Suraj Shankar explain the otherworldly sounds of the musical saw.

Guido Friebel discusses the lack of gender parity in academic positions in economics.

Christianne Corbett and Robb Willer explore perceptions of electability of female political candidates.

A feature episode explores recent developments and future research directions in treating cystic fibrosis.

Martijn van de Pol reports that approximately half of the changes in the traits of 60 European bird species can be attributed to rising mean temperatures. 

Brenhin Keller and Kalin McDannell explore the origins of a worldwide gap in the geologic record spanning hundreds of millions to billions of years.