Chapter 1: Science as a Way of Learning: A Guide to the Natural WorldOverview |
Science has great impact on our lives now and stands to have greater impact on them in the future. Science is both a body of knowledge and a means of acquiring knowledge. Biology, a branch of science, is the study of life. The living world is complex and diverse; the theory of evolution explains that complexity and diversity.
1.1 How Does Science Impact the Everyday World?
Science is playing an increasingly important role in the everyday lives of Americans, as evidenced by weekly news regarding such issues as genetically modified food, disease, and the biotech industry.
Americans have an uneven knowledge about science. Almost 80 percent of adult Americans know that the continents are moving about the face of the Earth, for example, but one-quarter thinks the sun goes around the Earth.
Science is a body of knowledge, a collection of unified insights about nature, the evidence for which is an array of facts.
The unified insights of science are known as theories. A theory is a general set of principles, supported by evidence, that explains some aspect of nature.
Science can also be defined as a way of learning: a process of coming to understand the natural world through the testing of hypotheses.
Science works through the scientific method, in which an observation leads to the formulation of a question about the natural world. Then comes a hypothesis—an explanation that has not been proven to be true. The hypothesis may be tested through observation, through a series of experiments, or by statistical means.
Every assertion regarding the natural world is subject to challenge and revision. Results obtained in experiments must be reproducible. Any scientific hypothesis or claim must be falsifiable, meaning open to negation through means of scientific inquiry.
Biology is the study of life. Life is defined by a group of characteristics possessed by living things. Living things can assimilate energy, respond to their environment, maintain a relatively constant internal environment, and possess an inherited information base, encoded in DNA, that allows them to function. Living things can also reproduce, are composed of one or more cells, are evolved from other living things, and are highly organized compared to inanimate objects.
Life is organized in a hierarchical manner, running in increasing complexity from atoms to molecules and then in sequence to organelles, cells, tissues, organs, organisms, populations, communities, and the biosphere.
Until the early nineteenth century, biology was largely a descriptive science, meaning it catalogued and described the Earth’s living things. Beginning about the 1820s, however, life science researchers began to formulate biological theories, such as that life comes only from life and exists only within cells.
Biology’s subject matter—the living world—is notable for its diversity.
Biology’s chief unifying principle is evolution, which can be defined as the gradual modification of populations of living things over time, with this modification sometimes resulting in the development of new species.