This week on Lost in Science, Claire dives headfirst into the evolutionary echidna-and-egg conundrum: which came first — the placental mammal or the mammalian egg of our humble monotreme cousins? 

Then Stu explores fascinating new research into how artificial intelligence might help bring people back from conspiracy theories — not by arguing louder, but by engaging directly with the evidence that convinced them in the first place. Can AI help untangle deeply held beliefs?