Life has many different levels of organization, from the atom to complex organisms, to whole populations and ecosystems. The biological sciences look at life on one or more of these levels—at anything that is or has been alive. The field of biology also looks at the effects of surroundings on living things. People who study biology learn how living things work, how they relate to one another, and how they evolved. Studying biology teaches you to ask questions, judge evidence, and solve problems. Because living things vary greatly in how they live and where they came from, the field of biology is divided into many different specialty areas.
Most biologists are researchers of one type or another. Many teach and conduct studies at colleges and universities. Industry employs research biologists in such areas as biotechnology (the use of biological systems to produce new goods and services), drug development, and food processing. Non-research careers involving biology can be found in medicine, education, and environmental protection. Biology is the basic background needed for doing many things that are good for society: fighting disease through the creation of new medicines, developing conservation measures to protect animals and the environment, breeding better crops, evaluating food and drug safety, and even inventing support systems for life in space.
Biology did not develop as a science until the last few centuries B.C., when science began to be separated from religion, particularly with regard to medicine. Hippocrates, known as the father of medicine, greatly influenced this development, but it was Aristotle, a student of Plato, who established observation and analysis as biology's basic tools.
Throughout human history, discoveries in biology have profoundly affected daily life and the overall quality of living. From the third century B.C. to the second century A.D., agriculture and medicine were the main areas to benefit from biological studies. During the Middle Ages, Arab scientists applied what they learned from Greek discoveries to medicine. The Renaissance saw the rediscovery of Greek culture, which led to rapid advances in Italy, France, and Spain. There, during the 15th and 16th centuries, Leonardo da Vinci and Michelangelo became skilled anatomists while looking for perfection in art. In the mid-16th century, Andreas Vesalius introduced dissection as a teaching aid, creating detailed anatomical diagrams that became standards for future medical illustrations. In the 17th century, William Harvey introduced experimentation while studying the human circulatory system, which marked the beginning of understanding mammalian body systems.
Since that time, discoveries in biology have occurred at a fast and furious pace. Louis Pasteur developed vaccines and the field of immunology to prevent disease. Matthias Schleiden and Theodor Schwann correctly named the cell as the fundamental unit of all organisms. Gregor Mendel discovered the principles of heredity through his study of peas. While the 19th century saw many advances in cell study, the 20th century was dominated by studies and breakthroughs in biochemistry and molecular biology. In 1944, Oswald Avery and a team of scientists isolated and identified DNA (deoxyribonucleic acid) as the transmitter of genetic information. In 1953, James Watson and Francis Crick unraveled the complex structure of DNA to predict how it can carry the genetic code for all living matter. In 2003, the Human Genome Project completed a final map of the human genome, which identified all genes in human DNA and determined the sequence of its 3 billion chemical base pairs. The accomplishment marked a major advance in biology.
Recent advances and trends in biotechnology, such as improved cloning techniques, better understanding of human DNA, and new avenues of drug research will shape the future of life sciences.