Chapter 1
INTRODUCTION: THEN THEMES IN THE STUDY OF LIFE
Summary of Chapter 1, BIOLOGY, 10TH ED Campbell, by J.B. Reece et al. 2014.
Biology is the branch of science that deals with living organisms and vital processes.
Biologists study life at many different levels, from molecules to the global.
Some properties of life:
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Order in structure.
Evolutionary adaptation to the environment.
Response to the environment.
Regulation of physiological process causes a constant internal environment.
Energy processing in order to maintain life.
Growth and development is controlled by inherited genes.
Reproduction of their kind.
Evolution accounts
 For the unity and diversity of life.
 For the adaptation of organisms to their environment.
THE UNIFYING THEMES IN BIOLOGY.
1) A hierarchy of organization with novel properties at each level.
Biological organization is hierarchical. There is a hierarchy of structural levels.
At each level of organization, new properties appear (emerge) as a result of the relative simple
interactions of its components.
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This emergent properties were not present in the previous in previous, simpler
organizational levels.
These properties show the hierarchy of structural organization.
The emergent property cannot be reduced to the sum of its components. “The whole is
greater than its components.”
The vertical dimension of life goes from atoms to biosphere. See pages 4 and 5 in your
textbook.
Atoms  molecules  macromolecules → organelles → cells  tissues  organs  organ
systems  organisms  populations  community  ecosystem  biosphere
Atoms are the chemical building blocks of all matter.
Atoms bond to other atoms to form molecules.
Macromolecules are formed by the joining of smaller molecules, e.g. starch is made by millions
of glucose molecules arranged in a specific fashion.
Macromolecules and smaller molecules form minute structures that form part of the cell and
perform a specific function. These structures are called organelles.
Cells are the units of structure and function.
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Unicellular organisms
Multicellular organisms.
Tissues are made of similar cells that make a functional unit.
Organs are a specialized unit made of different tissues that perform a very specific function in
the body.
Organs are organized into organ systems that take care of a major need of the body. E.g.
stomach, intestines and liver work together with other organs in the processing and absorption
of nutrients.
Organ systems perform the major functions for sustaining alive the organism, the living entity.
There are tiers beyond the organism level.
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SPECIES: Organisms of the same kind that are genetically very similar and can breed in
the wild or without human interference, and produce live, fertile offspring.
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POPULATION: A population consists of all the members of a species living in a given
area at the same time.
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BIOLOGICAL COMMUNITY: A biological community is made of all of the populations of
organisms living in a particular area. The functioning of a community is based on energy
transformations.
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ECOSYSTEM: An ecosystem is made of the biological community and its physical, nonliving environment.
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An ecosystem has biotic and abiotic components.
First major process in an ecosystem is the recycling of nutrients.
Second major process is the flow of energy.
BIOSPHERE refers to that part of the Earth planet that is inhabited by organisms.
Ecology studies the interaction between organisms and their biotic and abiotic environment
Emergent properties are characteristics not found at lower levels.
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E. g. density is a characteristic of populations absent in individuals; organs are
absent in tissues.
Emergent properties are due to the arrangement and interaction of parts as complexity
increases.
A combination of components can form a more complex organization called a system. These
components work together to produce a result that the individual parts cannot cause
independently.
The resulting properties and functions are called emergent properties.
The resulting system has to be looked in its entirety in order to see the “emergent properties.”
With each step upward in the hierarchy of biological order, novel properties emerge that were
not present at the simpler levels of organization.
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A protein has properties that are not found in its amino acid components.
Emergent properties reflect a hierarchy of structural organization and the interaction of its
components.
The dilemma of Reductionism
Reductionism: taking a complex system apart into more manageable components in order to
understand how it works. Complex systems can be understood by studying its component parts.
We cannot explain a higher level of order by breaking it down into its components; e. g. a
dissected dog does not function as a dog.
It is practically impossible to understand the complexity of living things by looking at the whole.
We must take it apart into its components and study how they function.
2) Organisms interact with their environment
Organisms exchange matter and energy with their environment.
The environment consists of both living and non-living factors that surround the organism.
Nutrients (matter) are recycled in the environment.
Energy flows in one direction, from light to heat passing through many exchanging steps in
ecosystems formed by producers and consumers.
The flow of energy from a producer to a consumer is never 100%. Some energy is lost at every
step in the form of heat.
ABSTRACT (you can read this article at the CBU library)
Since 65 million years ago (Ma), Earth's climate has undergone a significant and complex evolution, the finer details
of which are now coming to light through investigations of deep-sea sediment cores. This evolution includes gradual
trends of warming and cooling driven by tectonic processes on time scales of 10 5to 107 years, rhythmic or periodic
cycles driven by orbital processes with 104- to 106-year cyclicity, and rare rapid aberrant shifts and extreme climate
transients with durations of 103 to 105 years. Here, recent progress in defining the evolution of global climate over the
Cenozoic Era is reviewed. We focus primarily on the periodic and anomalous components of variability over the early
portion of this era, as constrained by the latest generation of deep-sea isotope records. We also consider how this
improved perspective has led to the recognition of previously unforeseen mechanisms for altering climate.
Trends, Rhythms, and Aberrations in Global Climate 65 Ma to Present
James Zachos, Mark Pagani, Lisa Sloan, Ellen Thomas, Katharina Billups.
Science 27 April 2001, Vol. 292 no. 5517 pp. 686-693
3) Life requires energy transfer and transformation.
The sun is the ultimate source of the energy used by organisms.
Photosynthesis transforms radiant (light) energy into chemical energy that is used by
organisms
Chlorophyll molecules absorb the energy from the sun; electrons move to higher energy levels,
and the process of photosynthesis continues. See Chapter 10.
Photosynthetic organisms are called producers.
Consumers are organisms that feed on producers.
Energy flows through the ecosystem entering as light energy and eventually leaving as heat.
See fig. 1.5 and 1.6.
4) Structure and function are correlated at all levels of organization. See. Fig. 1.7
Biological structures provides information about how it is used, its function.
The function of a structure provides insight about how it is made.
5 ) Cells are the basic unit of structure and function in living organisms.
Details of this topic will be covered in chapters 6 and 7.
Cells are the basic units of structure and function.
A cell is lowest level of organization that can perform all the activities required for life.
The activities of organisms are all based on the activities of cells.
Organelles form part of cells. Cells are the units of structure and function of living things.
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Some organisms are unicellular; they are made of a single cell.
Others are formed by aggregates of billions of cells that perform different tasks in order
to maintain the entire organism alive. These organisms are multicellular.
There are two main types of cells based on their structure:
Prokaryotic cells LACK membrane-bound organelles and membrane-enclosed nucleus.
Eukaryotic cells HAVE membrane-bound organelles and a membrane-enclosed nucleus.
Prokaryotic cells
No nucleus
One DNA
Circular DNA, no free ends
Lack membrane bound organelles
Eukaryotic cells
Nucleus present
Several DNA strands in nucleus
Chromosomes with free ends
Have membrane bound organelles
5) The Cell’s Heritable Information
This topic will covered in chapters 14 to 17.
The continuity of life is based on heritable information in the form of DNA.
DNA = deoxyribonucleic acid
Genes are made of DNA.
Genes are the units of inheritance that transmit information from parents to offspring.
DNA structure
DNA is made of a double helix.
Each strand of the helix is made of four kinds of molecules called nucleotides. See fig. 1.11.
The sequential arrangement of these four nucleotides contain encoded the precise information
of a gene. This arrangement makes the genetic code.
All forms of life employ the same genetic code. The genetic code is universal.
The entire set of genetic information contained in a cell is called the genome. The genome is
found in the chromosomes.
The chromosomes of the two types of cell differ in the way the DNA is organized with
associated proteins.
The part of the eukaryotic cells that is not nucleus is called cytosol. The organelles are found
suspended in the cytosol.
The entire process by which the information in a gene directs the production of a cellular
product is called gene expression.
Research developments that have permitted the systems biology to happen:
1. High-throughput technology that analyzes biological material rapidly and produces
enormous volume of data.
2. Bioinformatics allows the storage, organization, analysis, and integration of the data
produced by high-throughput technology through the use of computers, software and
mathematical models.
6) Feedback mechanisms regulate biological systems.
In feedback regulation, the product or output regulates the very process that produces it.
There are positive and negative feedback mechanisms.
See fig. 1.13.
Key ideas of this section:
1. There is a hierarchy of organization from atoms to organisms. Ecological organization
also shows a hierarchy of complexity. Emergent properties appear with each step
upward in level.
2. Regulatory mechanisms ensure a dynamic balance within certain range of requirements.
3. Organisms are open systems and interact with their surroundings in order to exchange
materials and obtain energy.
4. All organisms must perform work, which requires energy.
5. Cells are the basic unit of structure and function. There are two main types of cells:
prokaryotic and eukaryotic cells.
6. The continuity of life depends on the inheritable information contained in DNA.
7. Feedback mechanisms regulate biological systems.
EVOLUTION ACCOUNTS FOR THE UNITY AND DIVERSITY OF LIFE
1) Diversity and unity: the three domains of life.
Biologists have identified about 1.8 million species.
 5,200 prokaryotes
 100,000 fungi
 290,000 plants
 52,000 vertebrates
 1,000,000 insects
“Here we show that the higher taxonomic classification of species (i.e., the assignment of species to phylum, class, order, family,
and genus) follows a consistent and predictable pattern from which the total number of species in a taxonomic group can be
estimated. This approach was validated against well-known taxa, and when applied to all domains of life, it predicts ~8.7 million
(±1.3 million SE) eukaryotic species globally, of which ~2.2 million (±0.18 million SE) are marine. In spite of 250 years of taxonomic
classification and over 1.2 million species already catalogued in a central database, our results suggest that some 86% of existing
species on Earth and 91% of species in the ocean still await description.”
Mora C, Tittensor DP, Adl S, Simpson AGB, Worm B (2011), How Many Species Are There on Earth and in the Ocean? PLoS
Biol 9(8): e1001127. doi:10.1371/journal.pbio.1001127
http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001127
Grouping of organisms: the basic concept.
Taxonomy is the science of classifying organisms.
The species is basic unit of classification.
Taxonomic classification is hierarchical: each level consists of groups of the previous lower
level.
Species  genus  family  order  class  phylum (division)  kingdom  domains
The broadest unit of classification is the domain.
All living organisms are classified into one of three domains: Bacteria, Archaea and Eukarya.
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Bacteria and Archaea are prokaryotic organisms.
Eukarya is a eukaryotic domain.
Originally the bacteria and the archaea were grouped into one kingdom, Monera or Prokaryota.
More recent evidence suggests that the archaea may be more closely related to eukaryotes
than to bacteria.
There are four kingdoms in the Eukarya: Protista, Fungi, Plantae and Animalia.
Some biologists split the kingdom Protista into several kingdoms.
The fungi, plant and animal kingdoms are distinguished partly by their mode of nutrition.
There is unity in the diversity of life. This unity is evident in:
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The universal genetic code.
Similar metabolic pathways or cell functions.
Similar cell structure
Key idea: Life shows diversity (many species) and unity (same genetic code) at the same time.
2) Evolution.
These topics will be covered in greater detail in chapters 22 to 24.
Evolution is one unifying biological theme.
Species change over time. This documented by the fossil record and other evidence.
In 1859, Charles Darwin published The Origin of Species in which he made two major points:
1. Species change, and contemporary species arose from a succession of ancestors
through a process of "descent with modification."
2. A mechanism of evolutionary change is natural selection.
Darwin made the following observations:
1. Individuals in a population vary in many inheritable traits.
2. Populations have the potential to produce more offspring than will survive or than the
environment can support. There is competition or a struggle for existence.
3. Individuals with traits best suited to the environment leave a larger number of offspring,
which increases the proportion of inheritable variations in the next generation. This
differential success in reproduction is what he called natural selection.
Natural selection does not create adaptations. It merely increases the frequency of inherited
variants that arise by chance.
When exposed to certain environmental pressures, certain inheritable variations favor the
reproductive success of some individuals over others.
The cumulative changes over a long period of time could produce a new species from an
ancestral one.
Descent with modification accounts for the both the unity and diversity of life.
This connection between species and its ancestors more and more remote is refer as the Tree
of Life in which each species is a “twig” of the “tree”.
If one population is fragmented into several subpopulations isolated in different environments,
two or more related species can result over long periods of time.
The evolutionary relationship of species is often presented in the form of a tree with branches.
This can form a “family tree” or a phylogenetic tree.
“The affinities of all the beings of the same class have sometimes been represented by a great tree. I believe this
simile largely speaks the truth. The green and budding twigs may represent existing species; and those produced
during former years may represent the long succession of extinct species. At each period of growth all the growing
twigs have tried to branch out on all sides, and to overtop and kill the surrounding twigs and branches, in the same
manner as species and groups of species have at all times overmastered other species in the great battle for life. The
limbs divided into great branches, and these into lesser and lesser branches, were themselves once, when the tree
was young, budding twigs; and this connection of the former and present buds by ramifying branches may well
represent the classification of all extinct and living species in groups subordinate to groups. Of the many twigs which
flourished when the tree was a mere bush, only two or three, now grown into great branches, yet survive and bear the
other branches; so with the species which lived during long-past geological periods, very few have left living and
modified descendants…”
Darwin, Charles (1872), The Origin of Species by Means of Natural Selection, or the
Preservation of Favoured Races in the Struggle for Life (6th ed.), London: John Murray, pages
104-105.
http://darwin-online.org.uk/content/frameset?viewtype=text&itemID=F391&pageseq=132
Researchers sort out the relationships among organisms using anatomical, geographical and
molecular data.
Key ideas of this section:
1. Organisms constantly adapt through evolution. Natural selection is the mechanism of
evolution.
2. The correlation of structure and function can be applied at all levels of organization.
See the Tree of Life project: http://tolweb.org/Life_on_Earth/1
SCIENTIFIC INQUIRY.
Inquiry is a search for information and explanation.
Science is a process that includes repeatable observations and testable hypotheses.
Discovery or descriptive science describes natural structures and processes as accurately as
possible through careful observation and analysis of data.
Data can be quantitative and qualitative.
Discovery science and induction.
Inductive reasoning begins with observations and draws conclusions: general principle.
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What do all these facts have in common?
From many examples to all possible examples: inductive leap.
Verifiable observations and measurements are the data (singular, datum) of discovery science.
This dependence on observations demystifies natural phenomena and distinguishes science
from supernatural explanations.
Inductive conclusions are generalizations that summarize many concurrent observations.
Hypothesis-based science.
A hypothesis is a tentative answer to some question. It is an educated guess.
Hypotheses must be testable.
Science cannot address the possibility of supernatural phenomena nor the validity of religious
beliefs.
Deductive reasoning begins with supplied information called premises, and draws conclusions
on the basis of that information.
Deductive reasoning makes predictions that can be used to test hypotheses.
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It discovers relationships between facts.
If…then: "If all organisms are made of cells and humans are organisms then
humans are made of cells."
Deductive process flows from general observations to a specific conclusion.
A good explanation of inductive and deductive reasoning:
http://skepdic.com/refuge/ctlessons/lesson1.html
The scientific method
It is not a rigid procedure. The number of steps presented here is just one way of presenting the
scientific method. Some of these steps can be merged into one or divided into several.
Requires evidence to logically solve problems.
1. Make observations.
- Curiosity.
2. Ask critical questions.
3. Do background research, e.g. review of the literature; talk to scientists.
4. Formulate hypothesis:
- A hypothesis is an educated guess proposed as a tentative answer to a specific
question or problem.
5. Predictions are logical consequences of the hypothesis.
- Make a prediction that can be tested.
6. Test the prediction: controlled experimentation.
– Control group: in a controlled experiment, the groups in which all variables are
held constant.
– The experimental group differs from the control group in only one variable.
– Both groups are then compared.
7. Collect data. Recorded observations are called data (sing. datum)
 One datum; two data.
8. Interpret data.
9. Draw conclusions.
- Hypothesis supported or not.
In a controlled experiment,
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The control group is the one in which all variables are held constant.
The experimental group is the one in which one factor or treatment is varied.
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The variable is the condition of an experiment that is subject to change and that may
influence the outcome of the experiment.
Additional information: http://teacher.nsrl.rochester.edu/phy_labs/appendixe/appendixe.html
http://www.sciencemadesimple.com/scientific_method.html
A scientific theory
A theory in science is a comprehensive explanation supported by abundant evidence, which is
widely accepted by the scientific community.
A theory is validated by a continuum of observations and experiments.
A theory is general enough to spin off many new, specific hypotheses that can be tested.
The common use of the word theory is more applicable to a hypothesis in science, and not to a
scientific theory.
A scientific theory produces many hypotheses that can be tested.
Scientific credibility depends on the repeatability of observations and experiments.
Models of ideas, structures, and processes help us understand scientific phenomena and make
predictions.
Science is a social process.
The work of scientists build on the work of other scientists that have come before.
Most scientists work in teams and research groups include both graduate and undergraduate
students.
Scientists subject one another to careful scrutiny and check on each other's claims by repeating
the experiments.
Integrity and ethics is key in scientific research.
Science and technology are associated.
Technology is a method or devise that applies scientific knowledge for some specific purpose.
In many instances, technology results from scientific discoveries applied to the development of
goods and services.
Many technologies are goal-oriented applications of science.
Not all technologies are applied science. Technology in general predates science.
Scientists have the responsibility to educate politicians, bureaucrats, corporate leaders, and
voters about how science works and about the potential benefits and hazards of specific
technologies.
There is an important and crucial relationship between science, technology and society.
1. Science is a process of inquiry.
2. Science and technology have an impact in society and is closely connected to the social
sciences.
SUMMARY
1. There is a hierarchy of organization from atoms to organisms. Ecological organization
also shows a hierarchy of complexity. Emergent properties appear with each step
upward in level.
2. Organisms are open systems and interact with their surroundings in order to exchange
materials and obtain energy.
3. Cells are the basic unit of structure and function. There are two main types of cells:
prokaryotic and eukaryotic cells.
4. The continuity of life depends on the inheritable information contained in DNA.
5. The correlation of structure and function can be applied at all levels of organization.
6. All organisms must perform work, which requires energy.
7. Regulatory mechanisms ensure a dynamic balance within certain range of requirements.
8. Life shows diversity (many species) and unity (same genetic code) at the same time.
9. Organisms constantly adapt through evolution. Natural selection is the mechanism of
evolution.
10. Science is a process of inquiry.
11. Science and technology have an impact in society and is closely connected to the social
sciences.
ANOTHER SUMMARY OF CHAPTER 1:
http://www.mansfield.ohio-state.edu/~sabedon/campbl01.htm