Relating to a body part that has become small and lost its use because of evolutionary change. (American Heritage Science Dictionary )
I've been intrigued by vestigial organs, ever since I was plagued with a bad low back pain, several decades ago, which continues. And as is my habit, I plagued all my doctor friends with questions.
Turns out, that we all have a tailbone, left over from the days, when we had more swinging lifestyles in jungles, and enjoyed swiping other people with tails, not to mention hanging from branches and so on with the help of tails. I had often wondered why a bone was there, when a tail looked so fleshy and pliable, and was amazed to know that inside a tail, there were structures similar to vertebrae in our backs. By and by , as we became bipeds with celebrated celebral cortexes, used our front(upper) limbs to fight and balance, the tails vanished, and what remained was , only the place to which they were attached, the tailbone.
Remember the time you tried to hold on to the floor platform edge of a moving crowded doubledecker bus as you tried to jump and climb in, and were pulled in by some good Samaritans ?
Well, if you only had not lost the Palmar Grasp reflex......
Babies have it. You hold out your finger , and their own fingers curl around it to hold tight. Even their toes curl in when you make them sit. This is an ancient leftover reflex, from the time of our monkey ancestors. Baby monkeys, clutched their mothers at the belly with both hands and feet, leaving the mother's both hands free, to navigate her movement away from danger. Human babies have this reflex till abut six months, after which it disappears and becomes vestigial.
Having done several leaps into moving trains and buses, and yearned for a grip at the edge of the surface, I am just wondering if this "palmar grasp" thing can stop being vestigial and come back.
Wisdom teeth are supposed to be a vestigial throwback to the times when we nicely chewed all our vegetables, straight off the trees, without the benefit of butter and pressure cookers. Many people wonder why they are called wisdom teeth. What can you say when sometimes wisdom also looks like it is becoming vestigial ? Today these are often removed, with additional trouble. You are damned if you remove them and damned if you don't.
Remember the last time you got goosebumps ? This is also a vestigial reflex. Our ancestors were hairy folks, and under stress, the hair would stand up , and form a layer of protection, besides forming an insulating warming layer. This would also make the animal look larger to a predator. Today we have evolved with not as much hair, and we mess around cosmetically, with what is left of it. But the body skin never forgets, and so the next time you get goosebumps after hearing a scary story, be grateful to your ancestors....
There are also some muscles in the ears which are vestigial. Macaque and other monkeys, have these muscles highly developed, and they are able to move their ears voluntarily at will, to hear dangerous sounds better. We too have these muscles, but they are useless. (You might think it is better to turn your ears instead of a big head to hear what others are surreptitiously saying about you, but no .)
Though it seems some folks with practice are able to move their ears at will. But then this inability is compensated by our ability to move our head in a horizontal plane, which is not so in most monkeys. I've often thought we lazy humans, with our refusal to listen to wise people, simply lost out on this ear moving ability.
Having delved into the past, I naturally worry how we will evolve into the future.
For one thing , we will definitely have uneven limbs, with one hand shorter . Why ?
Decades and centuries, of constantly walking around with your hand to the ear, continuously talking into the phone, will harm the musculature of the upper limb. Whatever skirts the outer edge of the elbow will kind of wear out. And whatever covers the inside edge of the elbow will be squished into oblivion. All with the permanently bent upper limb.
I am simply amazed at the people I see, on their way home from work, one hand on their bag, the other stuck to their ear, one behind the other, walking in an involuntary rhythm, constantly talking to someone on the phone. Watch them on escalators, food courts in malls, buses etc. As a "side" evolution, it may not be unwise to presume, that certain neck muscles habituated to fixing eyes on monitors and chin muscles habituated to adjusting and speaking into hands free microphones, may also decide to gracefully end their utility.
And now that we are such an advanced race, it makes sense to think of mental evolution.
The first thing that I anticipate is the enlargement of the parietal lobe of our brains , which is just above our foreheads, and contributes to the understanding and processing of numerics, and quantities.
Notice how the human race as represented in India, now refuses to count in anything less than crores. There is an entire set of folks, with such developed parietal lobes, that they have amazing understanding about numbers and money, and how they can make both, by hook or by crook. The current stream of corruption scams this year is just a beginning. Not for nothing, does the figure of ET, the extraterrestrial creature get designed with a big head.
Something else in danger of going vestigial is the rods in our eyes. There are rods and cones inside our eyes, that convey to the brain a sense of dark-and-light, and color, respectively via the optic nerve .
I can only talk about the Indian side of things, and suffice it to say, that given the national aversion to anything dark, like a complexion, the rods in our eyes will soon become vestigial rods. Given the tendency of our brains to develop neuroplasticity, I presume that the cones will then takeover that job of the rods, and will be able to show the dark in all its hues and colors, instead of black and white. The occipital lobe in the cortex at the back of the head that deals with vision issues, will simply bulge with all the overwork.
So stay tuned to see folks with huge foreheads and lumps at the back of their heads. It is clear that hairstyles will have to change, Though the possibility of beauty standards drastically changing cannot be denied.
I know there is a brain area that processes thoughts and reasoning. I just wonder what part of the brain allows thoughtlessness. That and the area that controls violent emotions will be the next to enlarge with overuse.
And so sometime , say in 2050, a Google image search (if it still exists then on screens) will show folks like us when someone searches on vestigial brains . With what they will call small parietal lobes, excessive rods in the eyes, equal length of upper limbs, and , maybe, just maybe, we being described as the last of the peaceful tribes.
One of our greatest scientists, whose brain was preserved and studied, Albert Einstein, Nobel Prize winner in Physics in 1921, who died in 1955, could actually see the connection between technology and evolution then when he said:
“It has become appallingly obvious that our technology has exceeded our humanity.”
I think he had something else besides rods and cones in his eyes.