Of what evolutionary value could it be for seals to be able to balance things on their noses?
I am no marine biologist but I can think of plenty of ways that a good sense of balance, coordination, and spatial intelligence would be very helpful in catching fish and penguins and evading Orcas. This doesn’t seem that mysterious to me.
The same as for bears to ride bicycles, or dogs to do backflips, or tigers to leap through flaming hoops. Just because an animal is capable of being trained to do something, doesn’t mean that specific act has to be of evolutionary significance.
Have you noticed that every time the seal balances a ball, honks a horn, claps his flippers, etc. someone gives it a fish? That’s all the value it needs!
Theirs or ours?
I’ve seen nature shows where a swimming seal will poke his snout up through a small hole in the ice to draw a breath. So there’s the evolutionary advantage to having the skeletal and muscular structure to be able to bend their head back and point their nose straight up.
The ability to balance things on their nose is presumably just a learned skill rather than a variation on some inherent trait.
To nit-pick, performing “seals” are actually sea lions, which occur in tropical, temperate, and subarctic waters and don’t usually encounter much sea-ice. True seals are the ones that make breathing holes in ice.
What evolutionary value is there in humans being able to ride unicycles, or play trombones?
Pretty sure they use the hairs on their nose to actually balance a ball.
Chicks dig musicians.
Musicians, sure. Not trombone players, though.
As for humans …
What do you call a trombonist who just broke up with his girlfriend?
Colibri and Lanzy are both right - the ‘seals’ seen balancing balls in circuses and other shows are usually sea lions, and they’re actually using their thick whiskers (vibrissae) to balance the balls - these vibrissae are unusually thick and able to support weight, hence their use in the trick. They’re also innervated with nerve fibers so they can better serve as sensory apparatus.
In nature, the vibrissae provide sensory information on pressure and flow of water around the sea lion, allowing it to find prey in murky or dark water, and follow the trails of other sea lions and aquatic animals as they move through the water ahead of the sea lion.
I’ve had occasion to post this somewhere in SD before, and I am pleased to repeat: the clarinet is the penis of the orchestra, according to Fellini’s Rehearsal.
I don’t doubt the whiskers play an important sensory role, but the footage I can find of sea lions balancing balls pretty clearly shows them actively balancing the ball by keeping their nose under its centre of mass. If they just perched the ball there on a basket of stiff whiskers, it would not be nearly so impressive an act.
The hot chicks love trombonists on unicycles.
They can keep the ball balanced because the whiskers are surrounding it. As neat as sea lions are, they don’t have human levels of hand/eye (heh!) coordination. Now that I think about it only a few humans would probably be able to balance a ball on their nose. The point of a finger is much easier because you can see where the ball is tumbling to and correct for that in a way you wouldn’t be able to when it’s on your nose because on your nose you’d have trouble seeing which way the ball was going to fall.
Most of the ball’s weight is certainly on the nose, I apologize if my earlier post implied that it was not, but the sea lion is definitely using its vibrissae to support the ball and to tell if the ball is starting to fall in one direction or the other.
Try watching this video: http://www.youtube.com/watch?v=IK-oqZ8g_HU
At about 0:15 and 0:20 you can see the reflected light off the vibrissae, which you’ll notice are erect, not in their resting position, and are surrounding the ball.
For comparison, look at this photo: http://upload.wikimedia.org/wikipedia/en/a/a2/Sea_lion_head.jpg
Those are the vibrissae in their resting position.
From what I’ve seen, they have superior reactions and balance skills compared to the average untrained human - for example, in thisvideo, the animal is jumping around, swimming and leaping whilst keeping the ball balanced. You can see that it is balancing the ball by continually moving under and just beyond the ball as it falls in any particular direction
It sounds like we’re saying pretty much the same thing - I don’t dispute at all that the whiskers are being used to sense the movement of the ball, and are extended so as to lay against the ball. I very much doubt, though, that they are providing any direct mechanical support at all for the weight or position of the ball.