Excerpts from 'Everything has a History'
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Haldane’s books are the best for communicating science to a layperson. He wrote almost 300 brilliant articles on popular science for ordinary workers, many of which were later collated into books such as ‘Everything has a History’, ‘Science in Everyday Life’ and ‘On Being the Right Size’. Here are two chapters from ‘Everything has a History’.
How Bees Communicate:
Eight years ago, I gave an account in ‘The Daily Worker’ of the early work of Von Frisch and others on the language of bees. In July 1947, I was at the London Zoo with Professor Hadorn of Zurich. We watched bees coming into the glass-fronted hive laden with pollen of different colours in the bags on their legs. He was able, by watching them, to tell me from what direction they had come, and roughly from what distance. So will you be, after reading this article.
The facts previously known were these. When a bee has found a rich source of pollen or honey, she comes back to the hive, and before handing it over to the other workers whose job it is to store it in the comb, she does a peculiar “dance”. During the dance other bees touch her with their antennae, so that they know what smell is associated with the kind of food in question. They then fly off to visit flowers of the same kind, or dishes of sugar water impregnated with the same smell, for example of peppermint.
When the flower or the sugar-water is placed within fifty yards of the hive, bees fly out in all directions to visit flowers or dishes with the same smell. But when they are placed at distances over about a hundred yards, they not merely fly out in the right direction, but for the right distance. As some of them arrive before the original finder has unloaded her honey or pollen, it is clear that she must have told them in which direction to go, and how far.
Von Frisch has discovered how the information is conveyed. If the food is within fifty yards, the finder always dances round and round. If it is more than a hundred the dance is quite different. She goes forward in a certain direction for an inch or two, waggling her abdomen, then runs back without any “dancing” and repeats the dance again and again. The more she has found, and the sweeter the sugar-water, the longer the dance lasts and therefore the more other bees are able to learn what smell is associated with food, and the more go to look for it.
If the finder dances the round dance they go out in all directions, but not for further than a hundred yards. The other kind of dance gives them the direction. The dances are generally carried out on the comb, but sometimes on the landing stage in front of a hive. If it is horizontal, the dancer moves in the direction of the food, and the other bees fly out in the direction of her dance.
If, however, the surface of the comb is vertical, something much odder happens. As the day goes on, the dancer moves in different directions after coming from the same place. Supposing the food is south-west from the hive, then at 9 a.m. the dancer moves horizontally to the left, at noon she moves at forty-five degrees upwards, at 3 p.m. vertically upwards, and so on. In fact, a dance upwards means that the food is in the same direction as the sun, a dance to the right that it is to the right of the sun, and so on. It is most remarkable that bees know the direction of the sun, even in cloudy weather. The distance is given by the rhythm of the dance. Food only 150 yards away elicits a dance with 40 tailwags a minute. This number sinks to 20 when the food is half a mile away and to only 8 at a distance of two miles.
Von Frisch believes that the same language is used by scouts which go out from a swarm of bees and come back to tell it where they have found a place suitable for a new hive. But this is uncertain, for swarming is rare, whereas hundreds of observations can be made every summer day in an ordinary hive.
Besides the dances, the bees have at least one other “word”, namely a sweet smell which they make when they have found rich food, and which attracts other bees to the place.
These observations seem to have a great philosophical importance. It is often said that animal “language” is a mere expression of the emotions, and cannot convey statements of fact. But it is clear that the bees can tell each other not merely that they have found food, but where they have found it. It is true that the bees’ language seems to be inborn, and not learned like ours. It is like that of the young lady in Shaw’s ‘Back to Methusaleh’ who emerges from an egg talking perfect Shavian English. However, some birds have to learn a good deal of their language. It is also clear that bees have an amazing sense of direction. If a hive is turned round the dancer moves over the comb in a carved path as if she had a compass needle in her head. Perhaps she has some kind of magnetic sense which we lack. Her perception of rhythm must also be superior to our own.
A reader may well ask whether it is not possible that Von Frisch is pulling our legs, or at least letting his imagination run away with him, and has invented the amazing story. The answer is that although he made some mistakes in his interpretations of dancing, most of his earlier work has not only been confirmed but applied in practice by Gubin, Komarov and others in the Soviet Union, as well as by Von Frisch himself in Germany and Australia.
Red clover is normally fertilised by bumble bees, and does not set seed without fertilisation. Bumble bees are not common enough to fertilise an area of an acre or more of red clover. And ordinary bees prefer other flowers as their probosces are not long enough to get all the nectar of a red clover flower. The following method is therefore used. Beehives are brought near to the clover fields. Glasses containing sugar water and red clover blossoms are placed among the clover. Bees soon find them and come back to dance. Their comrades fall for the propaganda and search for flowers with the correct smell. A few of them find the sugar-water. The majority search the clover flowers. They do not find much nectar there, but in their searches they carry pollen from one flower to another. Enough of them find sugar-water to keep up the stream of propaganda in the hive.
The system rather reminds me of the football pools where a few people win large prizes, but the vast majority merely enrich the organisers of the pools and keep the postal workers busy. Economically it pays the seedsmen. For an expenditure of about twelve pounds of sugar per acre over five weeks Von Frisch got an increased yield of 36 pounds of clover seed per acre. As a pound of clover seed cost as much as 16 pounds of sugar this was a good bargain, except perhaps for the bees.
Possibly an even bigger return could be got by inducing bees to visit orchards. It is important that the bees visiting prepared sugar-water should, if possible, perch on fruit blossom and also suck up juice into which blossom has been crushed to give it the right scent. I do not know whether we shall be able to learn the language of ants, and get them to clean our kitchen floors instead of raiding our sugar. But I am quite sure that research on these subjects will tell us things which we need to know, not only about animals, but about human societies.
Some Queer Beasts
I visit the London Zoo fairly constantly, but I suppose my taste in animals is rather different from most readers’. Still they may be interested in a scientist’s tastes, even if they don’t share them.
If I had to pick the most striking animal on show, I think my vote would go to a small fish called the mud-skipper. It lives in tropical mangrove swamps, and spends most of its time out of the water. At any rate those in the Zoo aquarium do so. The mud-skipper has fins, but at least one pair of them have a joint like an ankle, which enables it to use them for a clumsy kind of hopping on land. Its eyes bulge out of its head, and even move up and down like a frog’s. Have you ever watched a frog eating? It has no complete roof to its mouth, so its eyes move up and down when it eats. In fact it uses its eyes to help it to push food down its throat.
I like the mud-skipper because he is trying to do what our ancestors did when they came out of the water in Devonian times. He is obviously a fish, and some of his near relatives are quite typical fish. But he has turned one pair of fins into passable limbs. He gives one an idea of what the first ancestors of the land vertebrates were like. If any critics of evolution think that fish could not have come out of water and become amphibians, you can show them the mud-skipper. Fortunately for him, he does not know that he is about three hundred million years late in his attempts to colonise the land from the water.
A fish which is interesting from a very different point of view is the Cichild from the lake of Galilee. Not only is it almost certainly a fish of one of the kinds which the twelve apostles caught, but it was probably involved in a miracle. These fish have remarkable breeding habits. A pair of them scoop a hole in which the female lays her eggs. The male picks them up, and carries them round in his mouth for a week or more until some time after they have hatched. As these fish also generally use their mouth to remove stones from the hole where the eggs are laid, they would be quite likely to pick up a small coin if one were lying on the bottom. Now on one occasion the apostles are reported to have had no money to pay a tax, and to have got it by hooking a fish with a “penny” in its mouth. It seems likely that this fish was caught while making a nest.
My favourite house at the Zoo is what is called the Temporary Rodent House. It contains a number of rodents, which surpass all the other seventeen living orders of mammals both in numbers of individuals and of species. I should explain that the class of mammals, that is to say warm-blooded hairy animals which suckle their young, is divided into thirty-two orders, such as elephants, whales and porpoises, bats, and carnivores, which include cats, dogs, bears, weasels and so on. Fourteen of these orders are extinct.
But this house contains representatives of three orders which are not generally known. The hyrax looks rather like a guinea pig until you look at its feet carefully, or better, dissect it. It then turns out to be nearer to hoofed animals such as pigs. Actually it is fairly like the ancestral forms of many different mammalian orders about the time when the last of the chalk was being formed. But it has evolved much less than most of the others.
Then there are the sloth and the tree ant-eater, representing the order called Xenarthra, or edentates, which originated in South America and of which a few members have got to Central and North America. This order also includes giant sloths about as large as elephants, and armadillos six feet long. The ant-eater has no teeth at all, the sloth has very few and simple ones, and a very much worse temperature control than most mammals.
Finally there is the South African aardvark, the sole survivor of an order called the Tubulidentata. It has a nose like a pig’s, ears like a rabbit’s, and is possibly the champion digger of the world. It not only lives in a burrow, but gets its food by excavating white ants’ nests. Whereas the mole chooses soft earth in which to hunt worms, the aardvark works in hard and dry soil, and does it very well. If its den had not got a stout cement floor, it would be out of sight in a few minutes.
The same house contains several galagos, which are small lemurs not unlike one of the forms ancestral to men and monkeys. Unfortunately they do not like light, and to see them at their best you must visit the Zoo at night, which will not be possible till we have more coal. But in the night time they are astonishingly active and graceful.
Naturally I don’t expect other readers to share my tastes. I like to see a set of animals which illustrate the various possibilities of evolution, some of which have only rarely been taken. Of course some of the invertebrates have done much odder things, for example the hermit crabs which live in coiled shells, and have their bellies bent side ways to fit them, or the barnacles, which start life swimming about like little shrimps, and then glue their heads onto rocks and live by kicking food into their mouths with their back legs.
Every mode of life has its corresponding structure, and palaeontologists have a big task in trying to puzzle out how extinct animals lived from a study of their bones and teeth. On the whole they are pretty successful, but in one or two cases it is very hard to see how the animals worked. Perhaps it had some soft part of which we know nothing, like the chameleon’s tongue, which he can shoot out for a foot or so to catch flies.
Some vocations are equally queer. If you haven’t seen an aardvark you may find it hard to believe that there is such a beast. And if we didn’t know there were such people as stock-brokers and tick-tack men we might not credit their existence either. Perhaps both may become extinct within a comparatively short time, I even venture to hope within my own lifetime. After all we manage without druids, rain-makers, augurs, exorcists, and quite a number of other professions which have been considered important enough in the past. It might be worth while keeping a few members of these professions if they were as odd looking as ant-eaters or mud-skippers. But their lives have not modified their structure. So let them go, provided we can keep the aardvark.
J B S Haldane was on the editorial board of ‘The Daily Worker’. JBS used to say that every self-respecting worker should understand the nature of his/her work and the scientific principles underlying it. Consequently, he wrote these science articles for workers. The articles bear the lucid style and clarity of concepts. Haldane was not only a brilliant scientist but also a great science fiction writer. We have included two of his short stories, ‘Rats’ and ‘My Friend Mr. Leaky’ in the Stories section of Pitara.
2601 words |
26 minutes
Readability:
Grade 7 (12-13 year old children)
Based on Flesch–Kincaid readability scores
Filed under: planet earth
Tags: #dancers, #science, #dance, #sugar
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