Biology

Observations

Making Sense of the World through Observations

The true heart of science isn’t a bunch of facts — it’s the method that scientists use to gather those facts. Science is about exploring the natural world, making observations using the five senses, and attempting to make sense of16 Part I: Biology Basics those observations.

Scientists, including biologists, use two main approaches when trying to make sense of the natural world:

✓ Discovery science: When scientists seek out and observe living things, they’re engaging in discovery science, studying the natural world and looking for patterns that lead to new, tentative explanations of how things work (these explanations are called hypotheses). If a biologist doesn’t want to disturb an organism’s habitat, he or she may use observation to find out how a certain animal lives in its natural environment. Making useful scientific observations involves writing detailed notes about the routine of the animal for a long period of time (usually years) to be sure that the observations are accurate.
Many of the animals and plants you’re familiar with were first identified during a huge wave of discovery science that took place in the 1800s. Scientists called naturalists traveled the world drawing and describing every new living thing they could find. Discovery science continues today as biologists attempt to identify all the tiniest residents of planet Earth (bacteria and viruses) and explore the oceans to see the strange and fabulous creatures that lurk in its depths.

✓ Hypothesis-based science: When scientists test their understanding of the world through experimentation, they’re engaging in hypothesis-based science, which usually calls for following some variation of a process called the scientific method (see the next section for more on this). Modern biologists are using hypothesis-based science to try and understand many things, including the causes and potential cures of human diseases and how DNA controls the structure and function of living things.
Hypothesis-based science can be a bit more complex than discovery science, which is why we spend the next two sections introducing you to two important elements of hypothesis-based science: scientific method and experiment design.
Introducing the scientific method
The scientific method is basically a plan that scientists follow while performing scientific experiments and writing up the results. It allows experiments to be duplicated and results to be communicated uniformly.

Here’s the general process of the scientific method:

1. First, make observations and come up with questions.
The scientific method starts when scientists notice something and ask questions like “What’s that?” or “How does it work?” just like a child might when he sees something new.

2. Then form a hypothesis.
Much like Sherlock Holmes, scientists piece together clues to try and come up with the most likely hypothesis (explanation) for a set of observations. This hypothesis represents scientists’ thinking about possible answers to their questions. Say, for example, a marine biologist is exploring some rocks along a beach and finds a new worm-shaped creature he has never seen before. His hypothesis is therefore that the creature is some kind of worm.
One important point about a scientific hypothesis is that it must be testable, or falsifiable. In other words, it has to be an idea that you can support or reject by exploring the situation further using your five senses.

3. Next, make predictions and design experiments to test the idea(s).
Predictions set up the framework for an experiment to test a hypothesis, and they’re typically written as “if . . . then” statements. In the preceding worm example, the marine biologist predicts that if the creature is a worm, then its internal structures should look like those in other worms he has studied.

4. Test the idea(s) through experimentation.
Scientists must design their experiments carefully in order to test just one idea at a time (we explain how to set up a good experiment in the later “Designing experiments” section). As they conduct their experiments, scientists make observations using their five senses and record these observations as their results or data. Continuing with the worm example, the marine biologist tests his hypothesis by dissecting the wormlike creature, examining its internal parts carefully with the assistance of a microscope, and making detailed drawings of its internal structures.

5. Then make conclusions about the findings. Scientists interpret the results of their experiments through deductive reasoning, using their specific observations to test their general hypothesis. When making deductive conclusions, scientists consider their original hypothesis and ask whether it could still be true in light of the new information gathered during the experiment. If so, the hypothesis can remain as a possible explanation for how things work. If not, scientists reject the hypothesis and try to come up with an alternate explanation (a new hypothesis) that could explain what they’ve seen. In the earlier worm example, the marine biologist discovers that the internal structures of the wormlike creature look very similar to another type of worm he’s familiar with. He can therefore conclude that the new animal is likely a relative of that other type of worm.

6. Finally, communicate the conclusions with other scientists.
Communication is a huge part of science. Without it, discoveries can’t be passed on, and old conclusions can’t be tested with new experiments. When scientists complete some work, they write a paper that explains exactly what they did, what they saw, and what they concluded. Then they submit that paper to a scientific journal in their field. Scientists also present their work to other scientists at meetings, including those sponsored by scientific societies. In addition to sponsoring meetings, these societies support their respective disciplines by printing scientific journals and providing assistance to teachers and students in the field.