Introduction

Science is a process of discovery through which we build our understandings of the natural world. Science refers to both the process building knowledge and the body of knowledge produced through this process. Scientists work in many different ways, but all science relies on testing ideas by figuring out what expectations are generated by an idea and making observations to find out whether those expectations hold true. Science is defined by the following characteristics:

• Science focuses exclusively on the natural world. Science does not deal with supernatural questions.
• Science does not deal with moral/ethical questions. We use science to explain the observations we make about the natural world. How we interpret that information and what we choose to do with it is beyond the scope of science. In other words, science does not tell us how to use scientific knowledge.
• Science relies on testing and ruling out incorrect ideas. In science, we never prove anything to be true, we can only disprove all alternative explanations and repeatedly fail to disprove the correct explanation.
• Science is ongoing and tentative. Science is continually refining and expanding our knowledge of the universe, and as it does, it leads to new questions for future investigation. Science will never be “finished.” Accepted scientific ideas are reliable because they have been subjected to rigorous testing, but as new evidence is acquired and new perspectives emerge, these ideas can be revised.

Science is a way of learning about what is in the natural world, how the natural world works, and how the natural world got to be the way it is. It is not simply a collection of facts; rather, it is a path to understanding.

Here are some examples of questions that can be answered using science:

• What is the optimum humidity for the growth and proliferation of the giant puffball fungus (Calvatia gigantea)? If you want to learn more about this cool fungus, visit the following link: https://www.nps.gov/articles/species-spotlight-puffballs.htm
• Are birds attracted to other birds of a specific coloration?
• What virus causes a certain disease in a population of sheep?
• What dose of the antibiotic amoxicillin is optimal for treating pneumonia in an 80 year old?

It is important to note that science does not apply to every aspect of the human experience. Science only deals with explaining natural phenomena; it cannot be applied to answering moral, spiritual, or supernatural questions. Here are some examples of questions that CANNOT be answered using science:

• How mean is the Grinch compared to Santa Claus?
• Where do ghosts live?
• How ethical is it to genetically engineer human embryos? To learn more about designer babies, visit the following link: https://www.nature.com/articles/d41586-019-00673-1
• What is the effect of fairies on Texan woodland ecosystems?

Take some time to reflect on each of these questions in order to understand why they can or cannot be answered through the use of science.

 Because this is a biology class, we will be focusing on questions that can be answered scientifically. A scientific question is one that can be answered by using the process of science (testing hypotheses, making observations about the natural world, designing experiments).

Sometimes you will directly make observations yourself about the natural world that lead you to ask scientific questions, other times you might hear or read something that leads you to ask a question. Regardless of how you make your initial observation, you will want to do research about your topic before you start setting up an experiment. When you’re learning about a topic, it’s important to use credible sources of information.

Methods of Scientific Investigation

Curiosity and inquiry are the driving forces for the development of science. Scientists seek to understand the world and the way it operates. Two main pathways of scientific study are descriptive science and hypothesis-based science. Descriptive (or discovery) science aims to observe, explore, and discover, while hypothesis-based science begins with a specific question or problem and a potential answer or solution that can be tested. The boundary between these two forms of study is often blurred, because most scientific endeavors combine both approaches. Observations lead to questions, questions lead to forming a hypothesis as a possible answer to those questions, and then the hypothesis is tested. Thus, descriptive science and hypothesis-based science are in continuous dialogue.

Formulating and Testing Hypotheses

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 (Figure 1.1)  (1561–1626), who set up inductive methods for scientific inquiry.

The scientific process typically starts with an observation (often a problem to be solved) that leads to a question. Let’s think about a simple problem that starts with an observation and apply the scientific method to solve the problem. One Monday morning, a student arrives at class and quickly discovers that the classroom is too warm. That is an observation that also describes a problem: the classroom is too warm. The student then asks a question: “Why is the classroom so warm?”

Recall that a hypothesis is a suggested explanation that can be tested. To solve a problem, several hypotheses may be proposed. For example, one hypothesis might be, “The classroom is warm because no one turned on the air conditioning.” But there could be other responses to the question, and therefore other hypotheses may be proposed. A second hypothesis might be, “The classroom is warm because there is a power failure, and so the air conditioning doesn’t work.”

Hypotheses can be used to generate a prediction about the world. For example, the prediction for the first hypothesis might be, “If the student turns on the air conditioning, then the classroom will no longer be too warm.”

A hypothesis must be testable to ensure that it is valid. For example, a hypothesis that depends on what a bear thinks is not testable, because it can never be known what a bear thinks. It should also be falsifiable, meaning that it can be disproven by experimental results. An example of an unfalsifiable hypothesis is “Botticelli’s Birth of Venus is beautiful.” There is no experiment that might show this statement to be false.

To test a hypothesis, a researcher will conduct one or more experiments designed to eliminate one or more of the hypotheses. It is particularly important to note that a hypothesis can be disproven, or eliminated, but it can never be proven. Science does not deal in proofs like mathematics. If an experiment fails to disprove a hypothesis, then we find support for that explanation, but this is not to say that down the road a better explanation will not be found, or a more carefully designed experiment will be found to falsify the hypothesis.

Testing Hypotheses with Experiments

Often hypotheses ask whether one factor causes or affects an outcome of interest. A common way to test a causal hypotheses is a controlled experimental design. An independent variable (sometimes called a predictor) is the variable that the researcher predicts might cause or affect a specific outcome. The researcher will systemically vary the independent variable. The dependent variable (sometimes called the outcome) is the factor that the researcher predicts will be affected by the independent variable. In a controlled experiment, the researcher attempts to create conditions where the only difference between experimental conditions is the independent variable. They hold all other conditions and features constant throughout the experiment. These features that the researcher intentionally holds constant throughout the experiment to be controls. A control often takes form of being a part of the experiment where no independent variable is applied in order to see what would happen in the absence of any experimental manipulation.

In the example that follows, see if you can identify the independent variable, dependent variable, and controls. A researcher might conduct an experiment to test the hypothesis that phosphate limits the growth of algae in freshwater ponds. A series of artificial ponds are filled with water and half of them are treated by adding phosphate each week, while the other half are treated by adding a salt that is known not to be used by algae.

The independent variable here is the phosphate (or lack of phosphate), the experimental or treatment cases are the ponds with added phosphate and the control ponds are those with something inert added, such as the salt. Just adding something is also a control against the possibility that adding extra matter to the pond has an effect. If the treated ponds show lesser growth of algae, then we have found support for our hypothesis. If they do not, then we reject our hypothesis. Be aware that rejecting one hypothesis does not determine whether or not the other hypotheses can be accepted; it simply eliminates one hypothesis that is not valid.

In practice, the scientific method is not as rigid and structured as it might at first appear. Sometimes an experiment leads to conclusions that favor a change in approach; often, an experiment brings entirely new scientific questions to the puzzle. Many times, science does not operate in a linear fashion; instead, scientists continually draw inferences and make generalizations, finding patterns as their research proceeds.

Please refer to this link to gain an appreciation for why the scientific method is not truly the basic and in some senses, boring process as it is communicated to be in many scientific textbooks. Pay particular attention to the illustrated flowcharts.

Observations vs. Inferences

The scientific process typically starts with an observation (often a problem to be solved) that leads to a question. An observation is perceiving and recording information about a natural phenomenon using the senses or scientific instruments. In other words, an observation is a noticing of a fact. In contrast, an inference is a conclusion that one draws based on the observation. An inference is a conclusion that is drawn based on logical reasoning and the evidence that is observed.

For example, an arctic ecology researcher studying the behavior and dietary tendencies of polar bears in Greenland could observe that polar bears consume meat exclusively and have a particular jaw morphology. The researcher could infer that the jaw morphology had evolved to optimize effectiveness in consuming meat in response to selective pressures. The diet and jaw morphology are observed, but the causal relationship between them is an inference.

The tentative nature of science

The process of science involves systematically attempting to rule out hypotheses. As we rule out alternative explanations and consistently fail to rule out one explanation, we become more confident in the explanation we cannot disprove. However, we always retain skepticism and open to new ideas or alternative explanations. It is never possible to reach 100% certainty in a particular hypothesis. Science is ongoing, meaning it is continually refining and expanding our knowledge of the universe, and as it does, it leads to new questions for future investigation. Science will never be “finished.” As we learn new things and create new technologies that enable new types of data collection, we uncover new data that can overturn hypotheses we previously thought were accurate. As we build more and more evidence supporting a particular hypothesis, that hypothesis becomes provisionally accepted as our understanding of that particular natural phenomenon. When a set of interrelated hypotheses gain sufficient support, they become a theory. However, scientists must remain open to new ideas and follow the data. Even theories like gravity would be overturned if we uncovered data that disproved it.

Science is a social endeavor

Scientists must share their findings in order for other researchers to expand and build upon their discoveries. Collaboration with other scientists—when planning, conducting, and analyzing results—is important for scientific research. For this reason, important aspects of a scientist’s work are communicating with peers and disseminating results to peers. Scientists often share results by presenting them at a scientific meeting or conference, but this approach can reach only the select few who are present.

Scientists also publish their work so other scientists can learn about what they found, have the opportunity to reproduce their experiments, and to build on the findings. These publications are typically in the form of peer reviewed articles in scientific journals. Scientific articles typically go through a peer review process before they are published in a scientific journal. The peers who are reviewing the article are other experts in the specific field about which the paper is written. Before it is published, they review it to ensure the study was conducted with sound scientific methods and logic. This allows other scientists to critique experimental design, data, and conclusions before that information is published in a scientific journal. The peer review process of helps to ensure that the research in a scientific paper is original, significant, logical, and thorough.

Grant proposals, which are requests for research funding, are also subject to peer review. This helps funding agencies, such as the National Science Foundation and National Institutes for Health, ensure they are spending their limited funds to invest in the best science possible.

References

Adapted from Clark, M.A., Douglas, M., and Choi, J. (2018). Biology 2e. OpenStax. Retrieved from https://openstax.org/books/biology-2e/pages/1-introduction

Adapted from Bartee, L., Shriner, W., and Creech C. (n.d.) Principles of Biology. Pressbooks. Retrieved from

https://openoregon.pressbooks.pub/mhccmajorsbio/chapter/using-credible-sources/

Molnar, C., & Gair, J. (2015). Concepts of Biology – 1st Canadian Edition. BCcampus. Retrieved from https://opentextbc.ca/biology/