The lines are blurring, any which way you look. Thanks to the incredible pace of scientific progress, the very definition of what it means to be'human' is becoming an increasingly open question. In a world where living beings like genetically edited babies and human-animal hybrids are made to exist, the questions aren't only ethical, two biomedical experts argue in a new paper - they're legal, too. The legal definition of what a'human' being is has to adapt or expand somehow, they say, to recognise and protect whatever level of humanity, altered or otherwise, these lab-made life-forms actually possess. "Bioscientific advances are nibbling away at classical legal boundaries that form the bedrock of the normative structures on which societies are based," authors Bartha Maria Knoppers and Henry Greely write in their new policy forum paper.