Why do some butterflies mimic their neighboring species?
Some butterfly species mimic their neighboring poisonous species to ward off the predators. They often mimic their neighboring species by copying the latter’s colour pattern, along with producing an unpleasant smell and taste.
Birds and other predators that are familiar with the warning patterns or bright colours of the harmful species mistake these imitator butterflies for their harmful counterparts and go away.
One such species of butterflies which is good at mimicking is the Ecuador small postman butterfly, which imitates its equally poisonous rainforest neighbor the Ecuador postman butterfly.
Morse code is a method of transmitting electrical signals that are combinations of long and short sounds, flashes of light or electrical pulses – like a torch that flicks on and off. To understand the messages, the code must be known: the Morse alphabet. Samuel Morse, an American, invented it in 1833. The alphabet consists of dots and dashes: A dot stands for a short signal, a dash for a long one. An S is written as …, an O as - - - . This Means the emergency signal SOS is ‘… - - - …’ – three dots, three dashes, three dots. Amateur radio operators and telegraphy use this Morse code even today.
Blind people read by moving their fingers on raised dots. These can be on metal or plastic or can be pressed out of the paper from below. Different combinations of the dots result in letters, numbers, and punctuation marks. This dotted script was invented by 16-year-old Louis Braille in 1825. He had become blind when he was a small boy. In 1845, William Moon developed another script for the blind. It consists of rounded symbols, which are based on the letters of the alphabets. People who are not born blind and become blind only later in their life find it easier to learn the Moon script as compared to the Braille alphabet.
There are many cipher scripts. Children often write with lemon juice – the writing becomes visible only on ironing the page. During wars, spies think of many complicated systems to communicate. In the Second World War, the Germans bought a special typewriter, called Enigma meaning ‘puzzle’, for typing encoded radio messages. Its keyboard was connected to lamps. If one typed ‘D’, then an ‘A’, the encoded letter, glowed. The receiving radio operator also had an Enigma, which understood these messages.
Many of the early script languages did not use any letters, but used small pictures instead. Around 3500 B.C., the Sumerians in Mesopotamia invented the cuneiform script: Notches were made in wet clay tablets with a wooden handle. The clay tablets then dried and became hard. Initially, there were about 1500 picture – like symbols, from which 800 simplified symbols developed gradually. Many of these small notches put together resulted in a word – just like a picture puzzle of today or the script of the Chinese.
Alphabets are a standardized set of letters, each of which represents a sound that is spoken out loud. The alphabets, unlike the hieroglyphs of the ancient Egyptians or the picture symbols of the Mayans, are not based on a picture system. The English alphabet has 26 letters; out of which six are vowels. The Arabic alphabet has more letters and is also read in a different way: from right to left. In the earliest alphabet that we know, there were letters only for consonants. Starting from 1000 B.C., the Greeks introduced letters for vowels. The word ‘alphabet’ is derived from the first two letters of the Greek alphabet: alpha and beta.
People who have developed a cipher language know how difficult it is to do so. One way is to attach a certain syllable after vowels: such as ‘sche’ after a, ‘blo’ after ‘e’, ‘ning’ after ‘u’, and so on. ‘Apple pie’ then becomes ‘Ascheppleblo pieblo’. If you do not know how to decipher the text, it is almost impossible to understand what is written. In 1941, the Japanese secret service cracked the code used by the Americans, and Japan attacked USA. The Navajo – Indians in the US offered to develop a new radio code from their language, which was understood only by the Navajo at that time. No one was able to decode this till the end of the war.
A computer needs clear instructions, called programs, which are written by programmers. Today, our demands from computers are very high: Process images, compare thousands of medical data, send e-mails, and instruct robots to build a car. Different programming languages were developed over a period of time to meet all these requirements. With some languages, you can write commands to process data in a database, with others, robots can be controlled perfectly.
People who are hearing impaired communicate with the help of gestures – energetic movements of the hand accompanied by a lively facial expression. Like every other language, gestures must also be learnt. While speaking a person may need a lot of words to say ‘shall we cross the bridge’, but a single gesture suffices for the deaf. This language is also used at places where listening is not possible: under water by divers or in space by astronauts.
Almost 900 million people speak Chinese, which is the most widely spoken language of the world. Russian is at the second place followed by English. German, with around 100 million people speaking it, is at the tenth place. Many countries such as Germany or Norway generally speak only one language; in India hundreds of languages are spoken. If a country remains under a foreign influence for too long, native languages can die out. In Wales, which is a part of Great Britain, this almost happened because; barring a few adults, people could speak only English. Schools and radio programmes are now promoting the native language Celtic ‘Welsh’.
On many signs there is a text telling us what to do: ‘Exit’, ‘Diversion’, and ‘Parking’. People who cannot read the text of the signs can understand them through the figure or picture. For instance, the shape of the arrow on the signs for exit helps understand the direction of the exit. Some signs convey information by means of a picture: ‘Pedestrian crossing’ and ‘Play Street’ are some examples. Then there are signs the look the same in all countries, such as the signs for “Main road” and “Give way”. One can always understand a ‘STOP’ sign even if it is written in Arabic!
Both humans and animals communicate a lot through their body postures. A cat, when energy humps its back and its skin ruffles up so that it appears bigger and more dangerous. In this way, it warns its opponent not to come near. Humans frown when in doubt and smile when happy. We use the thumbs up or the thumbs down signs as common gestures of approval or disapproval by extending the thumb upward or downward. We also make use of a universal sign language; we know what an index finger on the lips or a waving hand is trying to tell us. But watch out: signs do not mean the same all over the world – if you make an ‘O’ with the index finger and the thumb, it means ‘okay’ in USA, but at other places it is an insult.
Dogs, bark, growl, and whine. Deer bell, mice squeak. When a bee has detected food, it informs the other bees by a kind of a dance, and whales inform each other by means of the whale song. Their sounds can be heard in water from several hundred kilometres. The communication of the whales has increasingly become difficult, because there are so many other sounds in the oceans now, like those of ships or of oil rigs. In general, animals of the same species communicate with one another without a problem; between species, there could be misunderstandings! For example, a cat purrs with satisfaction, but the dog may think that the cat is snarling at it!
A lot of organs such as lungs, larynx, mouth, pharynx, tongue, teeth, and brain participate in the speaking process. Although animals possess all these organs, their structure is different from that in the humans. For speaking, it is important to properly control the processes involved, mainly breathing. This is done for us by our brain. First the air is inhaled, and then deviated through the larynx from the lungs. The larynx has small muscles called the vocal cords. When the air passes through the stretched elastic vocal folds it causes them to vibrate, producing sound. The teeth, tongue, gums, and lips then form the words.