1.1 The study of life Read Online
Viewed from space, Earth offers no clues about the diversity of life forms that reside there. The first forms of life on Earth are thought to have been microorganisms that existed for billions of years in the ocean before plants and animals appeared. The mammals, birds, and flowers so familiar to us are all relatively recent, originating 130 to 200 million years ago. Humans have inhabited this planet for only the last 2.5 million years, and only in the last 200,000 years have humans started looking like we do today.
This introductory course in biology starts at the microscopic level, with molecules and cells. Before we get into the specifics of cell structure and behavior, however, lets take a cursory glance at the field of biology more generally. Though biology as we know it today is a relatively new field, we have been studying living things since the beginning of recorded history. The invention of the microscope was the turning point in the history of biology; it paved the way for scientists to discover bacteria and other tiny organisms and ultimately led to the modern cell theory of biology. You will notice that, unlike the core program courses you took in chemistry and physics, introductory biology does not have many mathematical laws and rules and does not require much math. Instead, you will learn a great number of new terms and concepts that will help you describe life at the smallest level. Over the course of this semester, you will recognize the ways in which the tiniest of molecules are involved in the way we go about our everyday lives. Note that this course is an alternative to BIO101B, and that you may choose to take either BIO101A or BIO101B in order to learn about molecular and cellular biology. These courses cover the same material but in a slightly different way.