Dolphins and Orcas Collaborate in Salmon Hunt, Five Genetic Clusters in Mental Health, and Cosmic Ecology from Supernovae

Summary

In this episode, New Scientist explores an unusual alliance in the Pacific where dolphins and northern resident orcas cooperate to hunt Chinook salmon, with dolphins snatching the leftovers as orcas bring catch to the surface. The show then delves into a landmark genetics study that collapses 14 mental health conditions into five underlying genetic groups, offering a new lens on diagnosis and biology while noting the overlap among conditions. It also introduces cosmic ecology, a concept suggesting that the way supernovae seed planetary systems with elements can influence the formation of Earth like worlds, widening where habitable planets might arise. Finally, the program highlights intriguing space findings from the James Webb Space Telescope and discussions about black hole stars.

Interspecies Cooperation in the Pacific

The segment on marine mammals describes how certain northern resident orcas in Vancouver Island interact with dolphins to hunt salmon, particularly Chinook salmon which can reach a meter in length. Researchers used video tags mounted on the whales to observe the feeding sequence: the dolphins locate prey using echolocation on the dark seafloor while the orcas execute the capture, and then surface where the dolphins feed on the scraps and on the fish guts that are thrown around during the process. The dynamic is complex, with debates about whether the dolphins gain a real foraging advantage or merely use the orcas as protection from other threats. The discussion also touches on whale culture and the existence of different orca ecotypes, including the mammal eating “angry teenagers” that roam the oceans, as well as the potential for variation in behavior across populations.

Five Genetic Clusters in Psychiatric Disorders

The genetics discussion centers on a study analyzing genetic variants across more than a million people. It finds that 14 mental health conditions cluster into five groups based on underlying biology. Overlaps between conditions are common and challenge neat diagnostic boundaries. The study emphasizes risk factors rather than determinism and notes that many variants have modest effect sizes, with environmental and lifestyle factors shaping outcomes. The interviewees discuss how this reshapes thinking about conditions like schizophrenia, bipolar disorder, depression, PTSD, anxiety, ADHD, autism, OCD, and eating disorders, and what this means for classification schemes like the DSM. The conversation also covers the biology behind these clusters, highlighting oligodendrocytes and excitatory neurons as potential avenues for understanding brain function in these disorders.

Cosmic Ecology and the Origins of Habitable Worlds

The cosmic ecology discussion proposes that the distribution of life supporting elements in the galaxy is influenced by supernova events. Modeling work suggests a two step process where initial elements produced in a supernova are complemented by cosmic ray interactions that generate other elements, matching signatures seen in meteorites. This framework implies that Earth like planets could form in a broader range of galactic environments than previously thought, not necessarily requiring proximity to a recent supernova. The segment also covers Cassiopeia A observations that reveal odd numbered elements such as potassium and chlorine, which are important for life as we know it. The potential implications for future missions, including the Habitable Worlds Observatory slated for the late 2030s to 2040s, are highlighted as a way to search for planets with life supporting element balances.

Space Discoveries and The Next Frontier

In the final space segment, the panel discusses emerging ideas around black hole stars, a concept where a black hole powers a giant gas structure rather than fusion. A JWST related discovery shows compact, red galaxies and hints of these objects in the early universe. The experts emphasize that this is a developing area, with a high degree of confidence but still questions about lifetimes and connections to supermassive black holes. The discussion underscores how these lines of inquiry could inform future observations and guide our search for life beyond Earth.