Benjamin Franklin, one of America's Founding Fathers, was not only a statesman but a scientist as well. He fabricated, among other things, the lightning arrester and the bifocal spectacles. While waiting to present his ambassadorial credentials, in 1774, to the British Crown (in vain, since the Crown still held America to be its colony), he dropped a spoonful of olive oil on the water surface of Clapham Common, and seeing it uniformly covering the entire surface (half an acre) of the water, suggested that this would be an efficient way to calm choppy and troubled waters.
He noted that the oil surface was extremely thin and widely spread, giving rise to prismatic colours. Agnes Pockels, who repeated this experiment in 1890, was able to estimate the thickness of each molecule of olive oil (remarkably correctly) to be millionth of a millimetre. He is also credited with having made the statement “Man is a tool-making animal.”
Had he been alive today, he would have gladly withdrawn this pronouncement. Increasingly, we are realizing that even “lesser” animals such as the monkey and the crow are sapient; they can make tools to serve a given purpose. Chimpanzees, our ancestors, use thin twigs of plants to ease out termites off their mounds and eat them. Until recently, this ability was thought to be in the sole domain of us, primates and at best mammals. But this hubris has also been broken a few years ago. It now appears that birds and bees too make tools!
That the common bird, the crow, can make a tool for a purpose was shown a few years ago by scientists in England. They had placed a piece of meat in a small vessel (a mini-bucket with an erect handle) and placed the vessel in a tall glass cylinder. The crow could see the meat but could not reach for it.
The scientists had placed a thin piece of metal wire nearby. The crow, torn with the desire to eat the meat, took the wire in mouth, found a place where it could bend the end like a hockey stick and eased out the bucket off the glass jar and ate the meat!
You can see the entire drama by going on to Google, and asking for YouTube and Tool-making crows. After watching this, an admiring viewer dryly remarks: “The average 4-year-old (human child) will stick their hand in these and their hand will most likely get stuck, and then there will be lots of screaming and crying for mommy.”
In fact, accessing “crow makes tools” gives us a variety of instances of brainy behaviour by the common (shall we say sapient) crow. In one such instance, crows in Japan are seen to drop walnuts (and similar nuts with thick shells) on the road, wait for cars to pass over and crack the shell, and carry away the nuts.
Tool making by animals goes even further in time, in evolution. In this week's “Science Now”, Rebecca Kessler describes tool making by fish in water! She reports how one professional diver Scott Gardner in the Australian Great barrier Reef heard an odd cracking sound. It was being made by a one-foot-long black spot tusk fish, which was holding a clam in its mouth and whacking it against a rock. As it cracked open, it swallowed the clam and swam on.
This too can be seen by accessing Google, and asking for Rebecca Kessler and tool by fish. Another fish, this one called archer fish, uses a different strategy. It uses water itself as a tool. It is seen to jet off streams of water at prey on coast, and as the prey is immobilized thus, comes over and dines of it.
Go even lower in evolution to the beetles. One particular beetle called the Papuan weevil has legs that turn inwards and outwards, and has circular threads within, which it uses to trap and eat the prey — the earliest natural chopsticks, if you will.
But by far the most stunning example of tool making comes from a spider described by the Australian scientist Greg Alchin. He described thus: As night falls, this spider comes out, selects a site and starts manufacturing a hand weapon — a silk ribbon net. This is to be thrown over its kill to immobilize and eat it.” This strategy appears remarkably similar to the Roman Retiarius gladiators, who did the same to their opponents. The spider is thus named the Retiarius spider.
Given all this, we need to ask the question: what constitutes a tool? A tool is made for a purpose. And if the purpose is changed, will the tool be accordingly modified or will a new tool be made? Put in another way, are these ‘tools' of the spider or weevil hard-wired into their genes and thus the physiology?
A tool is made for a purpose; if the purpose changes, will the tool be accordingly modified, or a new tool made? These latter require a mind to think and make judgements. It is no longer just instinct, but intelligence. Are the spider and insect capable of this; are they sapient? Clearly the crow and the monkey are. How far in ancestry or back in evolution can we trace thinking or sapience?