HOW IS BIOLOGY IMPORTANT TO YOU? Biologists do more than simply prod blobs and ask whether they are alive. They live with gorillas and collect fossils and listen to whales. They isolate viruses and grow mushrooms and grind up insects. They read the message encoded in the long molecules of heredity, and count how many times a hummingbird's wings beat each second. Perhaps most importantly, biologists attempt to describe the way in which human beings fit into the whole picture of life on earth. Only by understanding this can we deal appropriately with our own destiny. Life exists on earth in incredible diversity, and we are part of that diversity.
Biology is one of the most interesting of subjects because of its great variety. But not only is it fun, it also is an important subject for you and for everyone, simply because biology will affect your future life in many ways. The knowledge that biologists are gaining is of fundamental importance to our ability to manage the world's resources in a suitable manner, to prevent or cure diseases, and to improve the quality of our lives and those of our children and grandchildren. Biologists are working on many problems that critically affect our lives, and they are intended simply as illustrations of the importance and relevance of the work that is going on. Because the activities of biologists alter our lives in so many ways, an understanding of biology is becoming increasingly necessary for any educated person.
Answer the following questions.
1. What do biologists do?
2. Does life exists on earth in incredible diversity?
3. Why is the knowledge that biologists are gaining important?
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HISTORY OF BIOLOGY
In prehistoric times, people gradually developed a great deal of practical biological knowledge. They learned to grow many kinds of plants and to tame and raise certain animals. In ancient times, people of China, India and the Middle East accumulated further knowledge of plants and animals. For instance, they knew how to use numerous plants as medicines or poisons. The Egyptians learned some anatomy and physiology through embalming their dead.
The ancient Greeks made major advances in biology. Unlike most other people of the time, some Greek thinkers did not believe that gods or spirits caused natural events. Instead, they saw nature as operating according to laws that people could discover. About 400 B.C, a Greek physician named Hippocrates taught that diseases have only natural causes. He also emphasized the relationships among the parts of an organism and between an organism and its environment. Hippocrates is often called the father of modern medicine.
During the 300s B.C, the Greek philosopher Aristotle gathered a vast amount of information about plants and animals. He was one of the first thinkers to classify animals according to their own characteristics rather than according to their usefulness to people. Pliny the Elder, a Roman naturalist who lived during the first 100 years after Christ's birth, also collected many facts about plants and animals. He included the information in his 37-volume Natural History. During the 100s A.D. Galen, a Greek physician, who practiced medicine in Rome, contributed greatly to advances in anatomy and physiology. He gained much of his knowledge from treating injured gladiators and dissecting apes and pigs.
The growth of biological knowledge slowed during the Middle Ages, a 1,000-year period in European history that began in the 400s. However, works by Hippocrates, Aristotle, Galen, and other ancient authorities were collected, preserved, and translated by Arab scholars in the Middle East. The Arabs also made major contributions of their own to biology. The works of the ancient Greek and Arab scientists eventually made their way to Europe. During the Middle Ages the authority of the ancient writers was unquestioned, though their works contained many errors.
From the early 1300s to about 1600s a new spirit of inquiry spread across Western Europe. During this period, called the Renaissance, many anatomists and physiologists began to challenge the authority of the ancient writers. They believed that people should rely on experimentation and observation rather than accept without question the ideas of the ancients.
The, emphasis on observation stimulated the development of a high degree of naturalism and accuracy in biological illustration. During the late 1400s and early 1500s, the great Italian artist Leonardo da Vinci made hundreds of drawings of the human body in which he paid careful attention to detail and proportion. Leonardo based his work on dissections of human corpses. The first scientific textbook on human anatomy was published in 1543. This work, titled On the Fabric of the Human Body, was written by Andreas Vesalius, an anatomist born in what is now Belgium. The book, richly illustrated with exceptionally lifelike drawings of human anatomy, corrected many of Galen's mistaken ideas.
One of the most important discoveries in physiology in the 1600s was made by William Harvey, an English physician. In 1628, Harvey published the results of his experiments showing how blood, pumped by the heart circulates through the body.
During the 1700s Europeans came into increasing contact with distant parts of the world and thereby learned of many unfamiliar plants and animals. Naturalists realized that they needed a classification system that could include those plants and animals. In 1735 the Swedish naturalist Carolus Linnaeus (also called Karl von Linne) published a system of classification in which he grouped organisms according to structural similarities. His system forms the basis of scientific classification used today.
Classifying organisms according to structural similarities stimulated interest in comparative anatomy - the comparison of the anatomical structures of different organisms. The leading comparative anatomist of the late 1700s and early 1800s was Baron Cuvier of France. Cuvier noticed that most kinds of animals have one or another of a very few basic body types. He devised a system of classifying animals according to basic body types that is still used in modified form. Cuvier also applied the methods of comparative anatomy to another field he helped establish, paleontology - the study of prehistoric life.
Answer the following questions.
1.What kind of knowledge did prehistoric people develop?
2.What advances in biology did ancient Greeks make?
3.Why was Hippocrates called the father of medicine?
4.Why was the authority of ancient authors unquestioned in Europe?
5.When did a new spirit of inquiry spread across Western Europe?
6.What was Leonardo da Vinci's contribution to biology?
7.What important discoveries did Harvey make?
8.Whose system of classification of organisms is the basis of classification used today?
9.What other branches of biology can the methods of comparative anatomy be applied to?
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FROM THE HISTORY OF BOTANY
The science of botany traces back to the ancient Greco-Roman world but received its modern impetus in Europe in the 16th century, mainly through the work of various physicians and herbalists. These professionals in seeking plants useful in medicine began seriously to observe plants themselves, as reflected in the woodcuts with which their herbal books were illustrated.
In the 17th century, as a result of the earlier revival of learning and of increased facilities for travel and study n Europe and Asia, many more plants became known, and some botanists turned from medical botany to attempts to name and catalogue all known kinds of plants. The most celebrated early work of this kind was Illustrated Exposition of Plants (1623) by the Swiss scientist Gaspard Bauhin, who listed and described about 6,000 species.
In the 18th century the greatest figure in botany was the Swedish scientist Carolus Linnaeus. His most valuable and lasting contributions were his careful descriptions of approximately 6,000 species arranged in genera (the same arrangement used today), his collation of the species that he knew with the names and descriptions of previous botanists, and his rules of nomenclature. He established binomial nomenclature - i.e., the naming of each species by two words, of which the first is the name of the genus to which it belongs and the second is a qualifying word, usually an adjective.
Even in this early period botany was becoming specialized. While many botanists were occupied only with the classes and names of plants, the foundations of anatomy, morphology and physiology were being laid. The important field of genetics was initiated in the 19th century, principally through the work of the Austrian botanist Gregor Mendel.
Plants were of paramount importance to early man; he depended upon them as sources of food, shelter, clothing, medicine, ornament, tools and magic. Today it is known that in addition to their practical and economic values green plants are indispensable to all life on Earth. Through the process of photosynthesis plants transform energy from the sun into the chemical energy of food, which makes all life possible. A second unique and important capacity of green plants is the formation and release of oxygen as a by-product of photosynthesis. The oxygen of the atmosphere, so absolutely essential to many forms of life, represents the accumulation of over 3,500,000,000 years of photosynthesis by green plants.
Although the many steps in the process of photosynthesis have become fully understood only in recent years, even in prehistoric times man somehow recognized intuitively that some important relation existed between the sun and plants. Such recognition is suggested by the fact that in primitive tribes and early civilizations worship of the sun was often combined with the worship of plants.
Earliest man depended totally upon the natural resources of his environment, which, until he developed methods for hunting, consisted almost completely of plants. The behavior of pre-Stone Age man can be inferred by studying the botany of aboriginal peoples in various parts of the world. Isolated tribal groups in South America, Africa and New Guinea, for example, have extensive knowledge about plants and distinguish hundreds of kinds according to their utility, as edible, poisonous or otherwise important in their culture. They have developed surprisingly sophisticated systems of nomenclature and classification, which approximate the binomial system (i.e., generic and specific names) found in modern biology. The urge to recognize different kinds of plants and to give them names thus seems to be as old as the human race.
In time plants were not only collected by primitive man but also grown by him. This domestication resulted not only in the development of agriculture but also in a greater stability of human populations. From the settling down of agricultural peoples in places where they could depend upon adequate food supplies the first villages and the earliest civilizations came.
Because of the long preoccupation of man with plants a large body of folklore, general information and actual scientific data has accumulated, which has become the basis for the science of botany.
Fundamentally, botany remains a pure science including any research into the life of plants and limited only by man's technical means of satisfying his curiosity. It has often been considered an important part of a liberal education, not only because it is necessary for an understanding of agriculture, horticulture, forestry, pharmacology and other applied arts and sciences, but also because an understanding of plant life is related to life in general.
Because man has always been dependent upon plants and surrounded by them he has woven them into his designs, into the ornamentation of his life, even into his religious symbolism. A Persian carpet and a bedspread from a New England loom both employ conventional designs derived from the forms of flowers. Medieval painters and great masters of the Renaissance represented various revered figures surrounded by roses, lilies, violets and other flowers, which symbolized chastity, martyrdom, humility and other Christian attributes.
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