Peripheral (Vagal) Nerves regulating Heart Rate ( https://pubmed.ncbi.nlm.nih.gov/31028266/ ) How often do you stop and feel your heart?   I don’t mean symbolically.  I mean, how often do you have a conscious sensory experience of that space behind your sternum, atop your diaphragm, between your lungs? And does that sensory field – whatever its origin – inform your emotions, motivations, decisions?  Does your heart-sense inhere somehow in your sense of self? Clearly a heart can function...

Fin Whale (painting) from science writer Darren Naish Suppose you arrive at a fancy pool party , and everyone is casually filling their mouths with whole bottle of wine before taking a gulp. After a silent prayer for their livers, you can't help but wondering " Could I accomplish the same depraved feat?" To engulf so much wine, you guess that you'd need supremely elastic jowls.  And after swallowing, you’d ideally like your face to return to its original shape.   Thankfully such parties...

Shoulder as modified gill arch, Andrew Gillis 2016 The world's first shoulder was a wrinkle   in an embryo's neck, floating in the oceans...