What is Biology?

Philosophy of science is a vibrant area of philosophical discourse, which attempts to reason about the way we can come to know more about the universe through science and its methods. Philosophy of biology works to test biological practices and concepts for logical soundness, both as a kind of system of checks and balances and a method of perpetuating new ways of thinking about what biology is and what it ought to be like. Because it is so foundational, philosophy should spill out of any good description of what biology is and of what science is. One reason for this is students must fully grasp what science is before they understand what biology is, so it is only natural to begin our discussion of what biology is, what its theories are like, and what biologists do with a focus on philosophy of science and biology. However, it is important to realize that philosophy of biology is distinct from biology itself.


First, and foremost, biology is a science. Science is simply any study of how the world works reasoned out using naturalistic explanations. The highest goal of science is knowledge, so science can be thought of as the quest for knowledge, which may also be viewed as an innate part of the human experience. Often, our concept of science is synonymous with our understanding of scientific methods. And in the real world, the concepts lay people have about biology are based upon the relationship between what they know about biologists and their work.


If science is a way of seeking out answers to our questions about ourselves and the world around us, then how is this accomplished by biologists? Biology, like other sciences, is based on the idea of inquiry. Campbell and Reece (2007) define this as “the heart of science… a search for information and explanation, often focusing on specific questions.” If science is inquiry and inquiry is the quest for knowledge about the world and explanations of this knowledge, then it follows that the work of biologists must be centered upon observation and explanation; indeed, this is the case.

Observations are made by using our human senses to record qualitative (non-numerical) and quantitative (numerical) information about the world around us. We call this information, which are in essence facts about how the world is, data, which scientists use to make explanations about the natural world. Biologists make diverse observations from the color of fish fins to the size of neurons. Conclusions based on observations are drawn by a type of logic known as inductive reasoning, which is used to make generalizations from scientific data we gather. Explanations of generalizations based on facts represent the next logical step in scientific inquiry. After gathering facts and making generalizations, biologists and other scientists often develop hypotheses, which are educated guesses about specific questions making predictions that can be tested using another important scientific method, the experiment. Hypothesis-based science makes the jump from generalizations to understanding specific interactions, forces, structures, and so on, responsible for biological phenomena by using deductive reasoning (deduction), which creates a logical flow oppositely oriented with respect to inductive reasoning discussed above. In other words, deduction is the process by which we make the transfer from generalizations to specific results. This process allows scientists to draw the testable predictions integral to hypothesis-based science.


Here, it is important to emphasize that the straightforward scientific method of primary education (observation, hypothesis, prediction, test, etc.) in science represents only one description of the order of scientific methods. Many times in their career—even during one experiment or project (set of experiments)—biologists may use different methods or different ordering of research priorities to answer biological questions. In fact, some biologists never even conduct experiments, because in many cases they would be biologically harmful and or morally unacceptable!Another way to begin thinking about biology as a science might be to ask, what real world forces or tools are responsible for the advancement of science, of biology? An important point might be how the breadth of biological inquiry, not unlike other fields of science, has always been intimately linked with technological and theoretical advances. Many of these have been perpetuated by workers in the field of biology, however many important innovations in biology owe themselves to advances in other fields of science. Technological and theoretical advances are important because they detail the options available to biologists in terms of method and concepts upon which their inquiry is based. Thus, technology and theoretical improvement lead to better solutions of biological problems, including more rigorous tests of better equipped hypotheses. So, we see that it would be unrealistic to view biological science and other disciplines of scientific study as mutually exclusive entities. In his book, The Creation, E. O. Wilson (2006) notes,

“The ongoing explosive growth of knowledge, especially in thesciences, has resulted in a convergence of disciplines and created the reality,not just the rhetoric, of inter-disciplinary studies. Biology, for example, istoday a swiftly evolving kaleidoscope of hybrid subdisciplines… As aconsequence, what was once perceived as an epistemo-logical divide between thegreat branches of learning is now emerging from the academic fog as somethingfar different and much more interesting: a wide middle domain of mostlyunexplored phenomena open to a cooperative approach from both sides of theformer divide.”

Biology is continually advancing in new directions fueled by technology and theory, but a proportion of biological advances must always be attributed to the momentum generated by this middle domain and by the academy as a whole, resulting from the more generally intertwined nature of fields of science. For example, and a specific one at that, as chemical experiments reveal more about pieces of biological phenomena, biologists are better informed about their studies and therefore their work is accelerated.But if academia, if all of science is intertwined in this way, what features of biology distinguish it from other realms of science? Is there a point where the other sciences end and biology begins? There are minimally two approaches to solving this problem for the novice, explaining what makes biology similar to other fields of science then venturing on to its uniqueness, or explaining away what biology is not and should not be. Alternatively, one might go directly into the big picture of what biology really is beyond formal distinctions about science and its philosophy, then focus in on its more specific attributes. Now that we have discussed what science is and how biologists conduct scientific investigations, I will take the first step toward accomplishing the end of this alternative goal.


In simplest terms, biology is the study of life. More precisely, modern biological science represents a multi-faceted discipline exploring the complexity of living things, their history, their interactions with each other and their environments across fine (microscopic) and broad spatial (global) and temporal (historical) scales. Biology is divided into many specialty areas of research, which include, but are not limited to, cell biology, genetics, anatomy and physiology, ecology, systematics, and evolutionary biology. An educated view of what biology is best approached by a top-down approach. So, before we go any further, we should begin with the big picture.The earth is our home, our place in the universe, the only life-bearing planet of its kind known to humanity. Much of the earth’s mass is composed of rocky and molten geophysical components, yet a thin film of life surrounds the globe at its surface. The biosphere is the name given to all the places on earth sustaining living things. Notice this concept does not include the whole planet necessarily, but we do know that most of the earth’s surface is habitable. The biosphere, in turn may be subdivided into ecosystems composed of communities, which are groups of populations. Populations are a little tricky to define, but the traditional definition is that of all the individuals of a particular species in one place at one time. Populations are subdivided into individual creatures which are all engaged in a fight to survive and reproduce in an often changing environment.

Figure 1. Hierarchical organization of biological systems from molecules to the biosphere (http://www.mie.utoronto.ca/labs/lcdlab/biopic/fig/1.9.jpg).


But biological organization goes further still. Based on years of study, we know that individuals are composed of organ systems or tissue layers that are in reality groups of specialized cells, fundamental units of biological structure and function. Some organisms are actually single cells, while others are multicellular. At the level of the cell, a whole new universe of biological interactions open up. Using different imaging techniques, including microscopy and histological sectioning, we observe that cells are composed of many different cellular features, many of them specific to the type of cell in question. So, we see that organic, biological nature can be studied by the biologist at a number of different levels of naturally occurring hierarchical organization (Fig. 1). Differences in levels of organization chosen for study by biologists are responsible for the subdivisions of biological science mentioned above. From this short discussion, we see that biology covers an enormous range of living phenomena and that biologists have an immense amount of living material available to work with.


There is a level of biological organization that I have failed to mention. I will address this level after briefly digressing to discuss a familiar phrase that you might hear in an introductory biology class. One way of viewing the relationship between biology and the other sciences is captured in the familiar axiom, “All biology is chemistry, all chemistry is physics, and all physics is mathematics.” This phrase may be interpreted in a variety of contexts. Many, including myself, consider it a gross and sometimes unhelpful oversimplification. It does, however, have a few interesting things to say about biology and science which cannot be doubted. First, it brings an important biological paradox to light, namely that at smaller scales all biological entities are composed of non-living chemical substances. It is very important that the student recognizes the biotic (living) and abiotic (non-living) levels of biological organization: below the cellular and organelle levels, life breaks down into chemical constituents, which can be further subdivided on the basis of their structure and function as they relate to one another and the rest of the biosphere (more later). Second, it highlights the important link between natural and physical sciences. Third, it notes the connection of all sciences with what some (mostly physical scientists, statisticians, and mathematicians!) consider the most basic and inescapable truth of the universe, mathematics. Ultimately, standing alone, this phrase fails in helping us understand what biology really is, but it does offer a great road map for rounding out our knowledge of hierarchical biological organization as I have shown—by including biochemical substances.


Campbell and Reece (2007) list eleven themes that unify biology (p.27), including (1) the cell as the basic unit of structure and function; (2) the idea that the continuity of life depends on the inheritance of hereditary information encoded in the form of specific nucleotide sequences of deoxyribonucleic acid (DNA) molecules; (3) the interconnected facts (a) that biological systems are more than the sum of their parts, (b) that the biosphere shows a hierarchical kind of organization, and (c) new properties emerge as we travel up the hierarchical structure of living things which were not apparent at lower levels; (4) the ubiquity of regulation in biological systems, where we find that feedback mechanisms and other forms of regulation attempt to maintain stable physiological or chemical states; (5) the idea that living things are important parts of their environment, interact with it, exchange energy with it, and thus change their environments; (6) two related ideas that (a) living things place energetic demands on their environments as a function of the caloric costs of their metabolism involved in the work organisms carry out from sub-cellular to organismal levels and that similarly (b) energy flows through the biosphere from the sun to producers and on to consumers, and this energy leaves ecosystems and organisms in the form of heat energy; (7) while a great phenotypic diversity is seen in the biosphere, (a) the great variety of biological forms and their interactions arise from a much less diverse (similar) pool of genes and (b) all living things arose from a single common ancestor some billions of years ago; (8) evolution is the unifying fact of all biology which explains the unity and diversity we observe in the living world; (9) structure and function are intimately linked throughout the hierarchical organization of biological systems; (10) as I have focused upon thus far, biology is inherently scientific, thus based on inquiry and subject to the methods and philosophy of science; and, finally, (11) biology is not disconnected from other fields of inquiry, but has important applications and implications for individuals, society, other sciences, technological innovation, human societies, and the planet at large.


HERE: I'M SKIPPING BASIC CHEMISTRY, BIOCHEMISTRY, AND RELATIONSHIPS BETWEEN THESE VARIABLES AND THE FITNESS OF THE NATURAL ENVIRONMENTS OF THE EARTH FOR SUSTAINING LIFE. NOTE: The cell, genetics, and mechanisms of organic evolution will comprise the focus of the following discussion.See "References" Link for more information about sources and extra reading materials (If not on sidebar, it's coming).