INTRODUCTION A male robin feeds an earthworm to his unfledged young Scientists who study birds are known as ornithologists Mike Truchon Shutterstock com
INTRODUCTION ife has existed on Earth for billions of years always changing and adapt ing New forms of life have evolved as old ones have become extinct From the first simplest organisms Earth has given rise to mil lions of species Some are familiar the various kinds of plants and animals that we know but many more are so tiny or so rare that they are known only to a handful of specialists Scientists who study living organisms are biologists Within that broad definition are dozens of subspecialties Some biologists study a certain category of life while oth ers focus on the patterns that connect all life forms Biologists look at the big picture environments and organisms as well as the tiny building blocks of cells and molecules Although there has been life on Earth for a long time it was not always here In its first billion years Earth was a planet made up only of inanimate substances such as minerals and gases The mysteries surrounding how life first came to exist are some of the most fascinating in the field of biology Equally fascinating are the questions concerning how life forms have adapted or failed to adapt to their envi ronments Why are some plants carnivorous Why did the dodo bird become extinct Why are some bacteria deadly to humans but cause
BIOLOGY UNDERSTANDING LIVING MATTER no harm to other animals Why do humans have blood but trees have sap How do some species survive in extreme temperatures Life is not only infinitely variable but also incred ibly tenacious Although individual organisms within a species die and even an entire spe cies may become extinct die out life itself SurVVes As recently as a few centuries ago people had little idea how life initially began nor did they understand exactly how it worked They had neither the tools nor the vocabulary to accurately observe and describe the incredible complexity of living organisms The tireless work of several influential scientists helped change that by offering explanations to how and why species change over time and by developing systems to categorize an eventual torrent of biological information The study of biology is vast encompass ing an understanding of what defines life and how life works and how it continues to change The following pages examine the discipline of biology as a whole They not only look at the fundamentals of biologi cal processes and how species relate to each other and the environment but also explore the important discoveries that have influ enced biology over the centuries and how the 10
INTRODUCTION different disciplines within biology interact with each other As the body of knowledge grows biolo gists can provide insights that help in other fields such as medicine anthropology and even history As environmental issues become more pressing biology can inform the debate about how these problems arose and how to find solutions Biologists have answered some of the questions of how life works but many questions remain and new ones constantly arise Indeed perhaps the most intriguing questions to consider are those that have not yet been asked 11
