Functionally, that is.
In other words, what is the purpose of the collarbone? Does it serve a function or is it a vestige we owe to our ancestors who walked on all fours and brachiated in trees?
I like to think of the collarbone as the shoulder’s flying buttress.
But I’m like that.
It keeps your shoulders away from your neck for one thing…
Mine has broken a few times, though I’m not sure I’d call that a function.
It stabilizes the shoulder, and aids in abduction, and internal and external rotation. Among other movements. Without it, the shoulder would be even more likely to dislocate, and would not have the strength or range. Fuse the acromio-clavicular joint, and you get reduced motion also, but improved strength, or at least force, along certain axes.
Qadgop, MD
It also provides a lovely adornment to the female form. One that does not decline with age.
A friend of mine has a partially artificial collarbone (i.e., her left side is artificial, right is not). When she had her first surgery, she knew it had failed because her rib cage was sagging.
And now the artificial one’s resonant frequency gets hit when she goes on car trips. Owwwch.
So it also supports the rib cage. At least partially.
Bravo! I love collarbones.
My nominee for best clavicles: Counselor Troy from Star Trek TNG.
You mean I was right? 
Indeed, Marina Sirtis is one kalê Hellênikê gynê.
Dave Marinaccio, author of All I Really Need to Know I Learned from Watching Star Trek, accused TNG of dressing Deanna Troi in a “boob uniform” to “reveal her ample cleavage.” But I would say that her [http://www.sirtis.co.uk/images/troi/sirtisdt106.jpg"]décolleté look was really designed to make the most of her luscious clavicle.
Actually, I think our 4-legged cousins don’t need it as much. In cats (housecats at least), it’s a floating bone, barely more than a half-toothpick-looking sliver. Therefore, cats’ front legs are attached to their torso only by tendons and/or ligaments - no bone-to-bone attachment.
As an aside, my daughter broke her right collarbone as she was being born! How’s that for an early injury!?