This week South Korea announced they will be adjusting the Civilian Controlled Zone that borders the demilitarised area between North and South Korea. The reshuffle will allow thousands of civilians to be able to move with more freedoms, but for the Unexpected Elements team, it’s sparked a conversation about scientific borders, boundaries, lines and barriers.

First up, a look at the Wallace Line, an obscure ecological border in Indonesia that marks the boundary between Asian tigers and Australian kangaroos with Dr Ian McFadden from Queen Mary University. We learn about the blood-brain barrier, could new ‘shuttle’ technologies help deliver vital new medicines that could help with Alzheimer’s?

Plus, why conflict causes the cost of flights to rise, and one scientist’s attempt to map underground fungi networks.

All that, plus many more Unexpected Elements.

Presenter: Marnie Chesterton, with Candice Bailey and Paul Adepoju