Found only on a few islets off New Zealand, this small lizard like animal is a living fossil. It has remained almost totally unchanged from related forms that existed 200 million years ago, when dinosaurs roamed the Earth.
However, the tuatara?s actual claim to fame lies elsewhere. Like a very small number of animals such as the sea lamprey and some species of frogs, it possesses a cleft-like opening on top of its skull consisting of a lens and a retina connected by nerves to the brain.
Illustration/
Kasbekar Pratimkumar
This unique ?third eye? invisible only in young tuataras which have a translucent patch at the top centre of the skull. After four to six months, it becomes covered with opaque scales and pigment. Its purpose is so far unknown.
But the interesting point is that this photoreceptor is, in reality, a vastly modified pineal gland which is a gland found even in higher mammals such as man. Does this mean we all have the remnants or beginnings of a third eye too?
Historically, a least, it would seem so. Interest in a third eye can be traced back to the Cyclops in Homer?s Odyssey, the Sister Three?Eyes in the Grimms? fairy tales, and to our very own third eye of enlightenment.
Also, even as early as in the fourth century BC Herophilus, the Greek anatomist, believed that the pineal gland was a sphincter which regulated the flow of thought and aided visual acuity, while Rene Descartes was of the opinion that it functioned as a valve mediating between the body and soul. Closer to our own times, the crafty Lobsang Rampa made his millions peddling an aroused pineal eye.
But is there any basis for all this in fact? Yes, quite a lot. The first serious study for instance, reported in the American Anatomical Memoirs in 1919, established beyond doubt that the pineal organ had definitely evolved from a central light sensitive spot that could still be seen in some primitive reptiles.
Nevertheless until 1959 this pea-sized endocrine gland embedded deep in the depths of the brain was only thought to be a useless vestigial appendage left over from earlier times because its functions were not dearly understood.
In that same year, however, researchers at Yale University discovered that the pineal gland produced a hormone called melatonin and that it responded by an indirect route via the sympathetic part of the autonomic nervous system to quantitative changes in outside light to secrete appropriate amounts of the hormone.
Thereafter, what happens is again part mystery. In birds, for example, these ?eyes? may help in synchronising their internal biological clock as marked by the cycle of day and night and in lizards it could aid body heat regulation. But since in humans neither function is necessary, various other hypotheses have been put forward.
One such postulated function is the pineal?s possible role in the regulation of sexual matters through the interaction with light.
More recently it has been suggested that melatonin might be beneficial in the treatment and avoidance of jet lag. It may also reduce the development of some cancerous tumours, and taking it may slow down the ageing process.
However, just how true these claims are is still being debated and studied.
On the other hand, some people have also found an occult connection operating here, claiming that the pineal gland is the seat of all paranormal modes of cognition.
They maintain that a significantly evolved pineal gland, automatically means a spiritually or mystically attuned human being capable of telepathy and clairvoyance ? capable ultimately of unifying with the cosmos.
Is there something in this? Consider for a moment if you will the following argument. Melatonin, the hormone secreted by the pineal gland is actually synthesised in the pineal from serotonin and serotonin occurs abundantly in nature. It?s found for instance in dates, bananas and plums, but it?s nowhere more common than in a species of wild fig growing in the tropics.
These are those huge sprawling trees with familiar hanging roots we call the peepal or bo. It?s also called the bodhi tree.
Sitting cross-legged under one such tree more than 2,500 years ago, the Buddha gained enlightenment. Could he see something we didn?t?
Source: http://ww1.mid-day.com/columns/mukul_sh ... 135748.htm
