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The Study of Life The Science of Biology 1/34 7/16/2020 The Science of Biology | Boundless Biology Introduction to the Study of Biology
Biology is the study of life and living things through
rigorously-tested and peer-reviewed scienti c research
methods. LEARNING OBJECTIVES Describe the eld of biological science KEY TAKEAWAYS Key Points Biology has evolved as a eld of science
since it was rst studied in ancient
civilizations, although modern biology is
a relatively recent eld.
Science is a process that requires the
testing of ideas using evidence gathered
from the natural world. Science is
iterative in nature and involves critical
thinking, careful data collection, rigorous 2/34 7/16/2020 The Science of Biology | Boundless Biology peer review, and the communication of
results.
Science also refers to the body of
knowledge produced by scienti c
investigation.
Pseudoscience is a belief presented as
scienti c although it is not a product of
scienti c investigation.
Key Terms pseudoscience: Any belief purported to be scienti c or supported by science that
is not a product of scienti c investigation.
science: A process for learning about the natural world that tests ideas using
evidence gathered from nature.
Biology: A natural science concerned with the study of life and living
organisms. The Study of Life Biology is a natural science concerned with the study of
life and living organisms. Modern biology is a vast and
eclectic eld composed of many specialized disciplines
that study the structure, function, growth, distribution,
evolution, or other features of living organisms.
However, despite the broad scope of biology, there are 3/34 7/16/2020 The Science of Biology | Boundless Biology certain general and unifying concepts that govern all
study and research:
the cell is the basic unit of life
genes (consisting of DNA or RNA) are the basic
unit of heredity
evolution accounts for the unity and diversity seen
among living organisms
all organisms survive by consuming and
transforming energy
all organisms maintain a stable internal
environment 4/34 7/16/2020 The Science of Biology | Boundless Biology Biology: The Study of Life: A collection of organisms clockwise from top
left: bacteria, koala, fern, toadstool, tree frog, tarantula. Biological research indicates the rst forms of life on
Earth were microorganisms that existed for billions of
years before the evolution of larger organisms. The
mammals, birds, and owers so familiar to us are all
relatively recent, originating within the last 200 million
years. Modern-appearing humans, Homo sapiens, are a
relatively new species, having inhabited this planet for
only the last 200,000 years (approximately). Stromatolites: Stromatolites, sedimentary accretions formed by the actions
of cyanobacteria, provide fossil evidence of life on Earth about 3.5 billion
years ago. History of Biological Science Although modern biology is a relatively recent
development, sciences related to and included within it 5/34 7/16/2020 The Science of Biology | Boundless Biology have been studied since ancient times. Natural
philosophy was studied as early as the ancient
civilizations of Mesopotamia, Egypt, the Indian
subcontinent, and China. However, the origins of
modern biology and its approach to the study of nature
are most often traced back to ancient Greece. (Biology
is derived from the Greek word “bio” meaning “life” and
the su x “ology” meaning “study of.”)
Advances in microscopy also had a profound impact on
biological thinking. In the early 19th century, a number
of biologists pointed to the central importance of the cell
and in 1838, Schleiden and Schwann began promoting
the now universal ideas of the cell theory. Jean-Baptiste
Lamarck was the rst to present a coherent theory of
evolution, although it was the British naturalist Charles
Darwin who spread the theory of natural selection
throughout the scienti c community. In 1953, the
discovery of the double helical structure of DNA marked
the transition to the era of molecular genetics.
Science and Pseudoscience Science is a process for learning about the natural
world. Most scienti c investigations involve the testing
of potential answers to important research questions.
For example, oncologists ( cancer doctors) are
interested in nding out why some cancers respond well
to chemotherapy while others are una ected. Based on
their growing knowledge of molecular biology, some
doctors suspect a connection between a patient’s 6/34 7/16/2020 The Science of Biology | Boundless Biology genetics and their
response to
chemotherapy. Many
years of research have
produced numerous
scienti c papers
documenting the
evidence for a connection
between cancer,
genetics, and treatment
response. Once
published, scienti c
information is available
for anyone to read, learn
from, or even
question/dispute. This
makes science an Phrenology:
Dr.
Spurzheim’s
divisions of the organs of
phrenology marked externally :
Phrenology is a pseudoscience that
attempted to determine brain
function
and
personality
by
analyzing an individual’s skull. iterative, or cumulative,
process, where previous research is used as the
foundation for new research. Our current understanding
of any issue in the sciences is the culmination of all
previous work.
Pseudoscience is a belief presented as scienti c
although it is not a product of scienti c investigation.
Pseudoscience is often known as fringe or alternative
science. It usually lacks the carefully-controlled and
thoughtfully-interpreted experiments which provide the
foundation of the natural sciences and which contribute
to their advancement. 7/34 7/16/2020 The Science of Biology | Boundless Biology Scienti c Reasoning
Science is knowledge obtained from logical inferences
and deductive experimentation that attempts to
comprehend nature. LEARNING OBJECTIVES Compare and contrast theories and hypotheses KEY TAKEAWAYS Key Points A hypothesis is a
statement/prediction that can be tested
by experimentation.
A theory is an explanation for a set of
observations or phenomena that is
supported by extensive research and that
can be used as the basis for further
research.
Inductive reasoning draws on
observations to infer logical conclusions
based on the evidence.
Deductive reasoning is hypothesis-based
logical reasoning that deduces 8/34 7/16/2020 The Science of Biology | Boundless Biology conclusions from test results.
Key Terms theory: a well-substantiated explanation of some aspect of the natural world
based on knowledge that has been
repeatedly con rmed through
observation and experimentation
hypothesis: a tentative conjecture explaining an observation, phenomenon,
or scienti c problem that can be tested
by further observation, investigation,
and/or experimentation The Process of Science Science (from the Latin scientia, meaning “knowledge”)
can be de ned as knowledge that covers general truths
or the operation of general laws, especially when
acquired and tested by the scienti c method. The steps
of the scienti c method will be examined in detail later,
but one of the most important aspects of this method is
the testing of hypotheses (testable statements) by
means of repeatable experiments. Although using the
scienti c method is inherent to science, it is inadequate
in determining what science is. This is because it is
relatively easy to apply the scienti c method to
disciplines such as physics and chemistry, but when it
comes to disciplines like archaeology,
paleoanthropology, psychology, and geology, the 9/34 7/16/2020 The Science of Biology | Boundless Biology scienti c method becomes less applicable as it
becomes more di cult to repeat experiments.
These areas of study are still sciences, however.
Consider archaeology: even though one cannot perform
repeatable experiments, hypotheses may still be
supported. For instance, an archaeologist can
hypothesize that an ancient culture existed based on
nding a piece of pottery. Further hypotheses could be
made about various characteristics of this culture. These
hypotheses may be found to be plausible (supported by
data) and tentatively accepted, or may be falsi ed and
rejected altogether (due to contradictions from data and
other ndings). A group of related hypotheses, that
have not been disproven, may eventually lead to the
development of a veri ed theory. A theory is a tested
and con rmed explanation for observations or
phenomena that is supported by a large body of
evidence. Science may be better de ned as elds of
study that attempt to comprehend the nature of the
universe.
Scienti c Reasoning One thing is common to all forms of science: an ultimate
goal “to know.” Curiosity and inquiry are the driving
forces for the development of science. Scientists seek
to understand the world and the way it operates. To do
this, they use two methods of logical thinking: inductive
reasoning and deductive reasoning. 10/34 7/16/2020 The Science of Biology | Boundless Biology Inductive reasoning is a
form of logical thinking
that uses related
observations to arrive at
a general conclusion. This
type of reasoning is
common in descriptive
science. A life scientist
such as a biologist makes
observations and records
them. These data can be
Scienti c Reasoning: Scientists
use two types of reasoning,
inductive and deductive, to advance
scienti c knowledge. qualitative or quantitative
and the raw data can be
supplemented with
drawings, pictures, photos, or videos. From many observations, the scientist
can infer conclusions (inductions) based on evidence.
Inductive reasoning involves formulating generalizations
inferred from careful observation and the analysis of a
large amount of data. Brain studies provide an example.
In this type of research, many live brains are observed
while people are doing a speci c activity, such as
viewing images of food. The part of the brain that “lights
up” during this activity is then predicted to be the part
controlling the response to the selected stimulus; in this
case, images of food. The “lighting up” of the various
areas of the brain is caused by excess absorption of
radioactive sugar derivatives by active areas of the
brain. The resultant increase in radioactivity is observed
by a scanner. Then researchers can stimulate that part
of the brain to see if similar responses result. 11/34 7/16/2020 The Science of Biology | Boundless Biology Deductive reasoning or deduction is the type of logic
used in hypothesis-based science. In deductive reason,
the pattern of thinking moves in the opposite direction
as compared to inductive reasoning. Deductive
reasoning is a form of logical thinking that uses a
general principle or law to forecast speci c results. From
those general principles, a scientist can extrapolate and
predict the speci c results that would be valid as long
as the general principles are valid. Studies in climate
change can illustrate this type of reasoning. For
example, scientists may predict that if the climate
becomes warmer in a particular region, then the
distribution of plants and animals should change. These
predictions have been written and tested, and many
such predicted changes have been observed, such as
the modi cation of arable areas for agriculture
correlated with changes in the average temperatures.
Both types of logical thinking are related to the two main
pathways of scienti c study: descriptive science and
hypothesis-based science. Descriptive (or discovery)
science, which is usually inductive, aims to observe,
explore, and discover, while hypothesis-based science,
which is usually deductive, begins with a speci c
question or problem and a potential answer or solution
that can be tested. The boundary between these two
forms of study is often blurred and most scienti c
endeavors combine both approaches. The fuzzy
boundary becomes apparent when thinking about how
easily observation can lead to speci c questions. For 12/34 7/16/2020 The Science of Biology | Boundless Biology example, a gentleman in the 1940s observed that the
burr seeds that stuck to his clothes and his dog’s fur had
a tiny hook structure. Upon closer inspection, he
discovered that the burrs’ gripping device was more
reliable than a zipper. He eventually developed a
company and produced the hook-and-loop fastener
popularly known today as Velcro. Descriptive science
and hypothesis-based science are in continuous
dialogue. A Burr: This fruit attaches to animal fur via the hooks on its surface to
improve distribution. Velcro is an example of a biomimetic invention which
has copied burrs and uses small exible hooks to reversibly attach to u y
surfaces. The Scienti c Method
The scienti c method is a process by which 13/34 7/16/2020 The Science of Biology | Boundless Biology observations are questioned; hypotheses are created
and tested; and the results are analyzed. LEARNING OBJECTIVES Discuss hypotheses and the components of a
scienti c experiment as part of the scienti c
method KEY TAKEAWAYS Key Points In the scienti c method, observations
lead to questions that require answers.
In the scienti c method, the hypothesis is
a testable statement proposed to answer
a question.
In the scienti c method, experiments
(often with controls and variables) are
devised to test hypotheses.
In the scienti c method, analysis of the
results of an experiment will lead to the
hypothesis being accepted or rejected.
Key Terms 14/34 7/16/2020 The Science of Biology | Boundless Biology scienti c method: a way of discovering knowledge based on making falsi able
predictions (hypotheses), testing them,
and developing theories based on
collected data
hypothesis: an educated guess that usually is found in an “if…then…” format
control group: a group that contains every feature of the experimental group
except it is not given the manipulation
that is hypothesized The Scienti c 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 scienti c method. The scienti c
method was used even in ancient times, but it was rst
documented by England’s Sir Francis Bacon (1561–1626)
who set up inductive methods for scienti c inquiry. The
scienti c method can be applied to almost all elds of
study as a logical, rational, problem-solving method.
The scienti c 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 scienti c method to
solve the problem. A teenager notices that his friend is 15/34 7/16/2020 The Science of Biology | Boundless Biology really tall and wonders
why. So his question
might be, “Why is my
friend so tall? ”
Proposing a Hypothesis Recall that a hypothesis is
an educated guess that
can be tested.
Hypotheses often also
include an explanation for
the educated guess. To
solve one problem,
several hypotheses may
be proposed. For
example, the student Sir Francis Bacon: Sir Francis
Bacon (1561–1626) is credited with
being the rst to de ne the scienti c
method. might believe that his
friend is tall because he drinks a lot of milk. So his
hypothesis might be “If a person drinks a lot of milk, then
they will grow to be very tall because milk is good for
your bones.” Generally, hypotheses have the format “If…
then…” Keep in mind that there could be other responses
to the question; therefore, other hypotheses may be
proposed. A second hypothesis might be, “If a person
has tall parents, then they will also be tall, because they
have the genes to be tall. ”
Once a hypothesis has been selected, the student can
make a prediction. A prediction is similar to a hypothesis
but it is truly a guess. For instance, they might predict 16/34 7/16/2020 The Science of Biology | Boundless Biology that their friend is tall
because he drinks a lot of
milk.
Testing a Hypothesis A valid hypothesis must
be testable. It should also
be falsi able, meaning
that it can be disproven
by experimental results.
Importantly, science does
not claim to “prove”
anything because
The Scienti c Method: The
scienti c method consists of a
series of well-de ned steps. If a
hypothesis is not supported by
experimental
data,
a
new
hypothesis can be proposed. scienti c understandings
are always subject to
modi cation with further
information. This step—
openness to disproving
ideas—is what distinguishes sciences from non-sciences. The presence
of the supernatural, for instance, is neither testable nor
falsi able. To test a hypothesis, a researcher will
conduct one or more experiments designed to eliminate
one or more of the hypotheses. Each experiment will
have one or more variables and one or more controls. A
variable is any part of the experiment that can vary or
change during the experiment. The control group
contains every feature of the experimental group except
it is not given the manipulation that is hypothesized. For
example, a control group could be a group of varied 17/34 7/16/2020 The Science of Biology | Boundless Biology teenagers that did not drink milk and they could be
compared to the experimental group, a group of varied
teenagers that did drink milk. Thus, if the results of the
experimental group di er from the control group, the
di erence must be due to the hypothesized
manipulation rather than some outside factor. To test the
rst hypothesis, the student would nd out if drinking
milk a ects height. If drinking milk has no a ect on
height, then there must be another reason for the height
of the friend. To test the second hypothesis, the student
could check whether or not his friend has tall parents.
Each hypothesis should be tested by carrying out
appropriate experiments. 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. Using the scienti c method,
the hypotheses that are inconsistent with experimental
data are rejected.
While this “tallness” example is based on observational
results, other hypotheses and experiments might have
clearer controls. For instance, a student might attend
class on Monday and realize she had di culty
concentrating on the lecture. One hypothesis to explain
this occurrence might be, “If I eat breakfast before class,
then I am better able to pay attention.” The student
could then design an experiment with a control to test
this hypothesis.
The scienti c method may seem too rigid and 18/34 7/16/2020 The Science of Biology | Boundless Biology structured. It is important to keep in mind that although
scientists often follow this sequence, there is exibility.
Many times, science does not operate in a linear
fashion. Instead, scientists continually draw inferences
and make generalizations, nding patterns as their
research proceeds. Scienti c reasoning is more complex
than the scienti c method alone suggests. Basic and Applied Science
Basic science increases the knowledge base of a eld of
research while applied science uses that knowledge to
solve speci c problems. LEARNING OBJECTIVES Di erentiate between basic and applied science KEY TAKEAWAYS Key Points The only goal of basic science research is
to increase the knowledge base of a
particular eld of study.
Applied science uses the knowledge
base supplied by basic science to devise 19/34 7/16/2020 The Science of Biology | Boundless Biology solutions, often technological, to speci c
problems.
The basic science involved in mapping
the human genome is leading to applied
science techniques that will diagnose
and treat genetic diseases.
Key Terms basic science: research done solely to expand the knowledge base
applied science: The discipline dealing with the art or science of applying
scienti c knowledge to practical
problems. Two Types of Science: Basic Science and Applied Science The scienti c community has been debating ...
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