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Biology LibreTexts

1: Introduction to Biology

  • Page ID
    24831
  • Biology is the study of living organisms, including their physical structure (from cells to whole individuals), chemical processes (such as metabolism), physiology, and development. This is a very broad definition because the scope of biology is vast. Biologists may study anything from the microscopic view of a cell to ecosystems and the whole living planet. Listening to the daily news, you will quickly realize how many aspects of biology are discussed every day. For example, recent news topics include Escherichia coli outbreaks in spinach and Salmonella contamination in peanut butter. Other subjects include efforts toward finding a cure for AIDS, Alzheimer’s disease, and cancer. On a global scale, many researchers are committed to finding ways to protect the planet, solve environmental issues, and reduce the effects of climate change. All of these diverse endeavors are related to different facets of the discipline of biology.

    What does the study of biology share with other scientific disciplines? Science (from the Latin scientia, meaning “knowledge”) can be defined as knowledge that covers general truths or the operation of general laws, especially when acquired and tested by the scientific method. It becomes clear from this definition that the application of the scientific method plays a major role in science. The scientific method is a method of research with defined steps that include experiments and careful observation.

    • 1.1: The Scientific Method
      Biologists study the living world by posing questions about it and seeking science-based responses. This approach is common to other sciences as well and is often referred to as the scientific method. The scientific method was used even in ancient times, but it was first documented by England’s Sir Francis Bacon (1561–1626), who set up inductive methods for scientific inquiry. The scientific method is not exclusively used by biologists but can be applied to almost all fields of study as a logica
    • 1.2 What is Ecology?
      Ecology is the study of how organisms interact with each other and with the physical environment in which they live. It is a large field of study and incorporates research at many spatial and temporal scales. Examples of ecological research include impacts of climatic change on species range distributions, patterns of infectious disease outbreaks, the effect of nutrient availability on ecosystem function, etc. In his 1911 book My First Summer in the Sierra, John Muir famously wrote ‘when we try
    • 1.3 What is Evolution?
      At its simplest, evolution is any change in heritable traits in a population of organisms across generations. These changes may be the result of natural selection, genetic drift, mutation, etc – processes that we will consider in depth later in the course. All populations experience evolutionary change, as influenced by their environment, their interactions with other organisms, and random chance. Like ecology, we can consider evolution at different scales.
    • 1.4 Linking Ecology and Evolution
      In 1973, evolutionary biologist Theodosius Dobzhansky wrote a now-famous essay titled Nothing in Biology Makes Sense Except in the Light of Evolution. In this essay, Dobzhansky argued that evolution is the underlying unifying theme for all of biological study and that understanding life on earth necessarily requires considering evolutionary processes and impacts. The title of this essay became a famous quote highlighting the foundational importance of evolution to all biological concepts and pro