Download The Science of Biology Ch 1 HB_2016

Evolution and the
Foundations of
Biology
Chapter 1
Overview: Inquiring About Life
 An
organism’s adaptations to its
environment are the result of evolution

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For example, a beach mouse’s light, dappled fur
acts as camouflage, allowing the mouse to blend
into its surroundings
Inland mice of the same species are darker in
color, matching their surroundings
 Evolution
is the process of change that
has transformed life on Earth
What is Biology?
 Biology
is the scientific study of life
 Biologists ask questions such as
How does a single cell develop into an
organism?
 How does the human mind work?
 How do different forms of life in a forest interact?

Study of Living Things

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Biology is the study of living things
Comes in a variety of shapes & forms
Biologists study life in many different ways
Also the study of diversity
(how living things work, interact in their
environment, & how they change over time)
WHAT CHARACTERISTICS
DEFINE LIFE?

All living organisms share a basic
characteristic
Properties (or Characteristics) of Life:
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1. Cellular organization: all organisms consist of
one or more cells (or order within internal &
external parts and how they interact with the
world)
2. Order: all living things are highly ordered…we
have many different types of cells
3. Sensitivity: all organisms respond to stimuli
4. Growth, development, and reproduction: must
pass on our genetics
Properties (or Characteristics) of Life:
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5. Energy utilization: all organisms use
energy in our body(this energy depends on
metabolism)
6. Evolutionary adaptation: all organisms
interact with other organisms & the
environment for survival.
7. Homeostasis: internal conditions suitable
for their environment
Think about this….

What must all living organisms be able to
do to be considered to be living?….thumbs
up if you know!
Studying diverse forms of life
reveals common themes
 To
organize and make sense of all the
information encountered in biology, focus
on a few big ideas
 These unifying themes help to organize
biological information
4 Themes that Unify
Biology
1. Theme:
Different levels of Biological Organization

Hierarchical Organization of the Biological
World
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The study of life extends from microscopic molecules to
the global scale of the earth
1. Population Level
2. Organism Level
3. Cellular Level
1 The
Biosphere
7
Tissues
2
Ecosystems
6 Organs
and Organ
Systems
10
Molecules
3
Communities
8
Cells
5
Organisms
4
Populations
9 Organelles
Population Level
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Biosphere: consist of life on earth and
the places where life exist
Ecosystem: the community & habitat
where it lives together in an
ecological system
Community: all the populations of
different species living together in one
place
Population: most basic a group of
organism of the same species living
in the same place
Species/Organism: its members
similar in appearance are able to
interbreed
1 The Biosphere
Fig. 1.2c4
Fig. 1.2c3
Fig. 1.2c1
Fig. 1.2b4
Organismal Level
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Organ systems: are groups of organs
(I.e. the nervous system consist of
sensory organs used by the brain,
spinal cord & neurons that send
signals to & from them)
Organs: are groups of tissues (i.e.
brain is an organ made of nerve cells &
connective tissue)
Tissues: the most basic level which are
groups of similar cells
Tissue
Organ
Organ system
Organism
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Fig. 1.2b3(TE Art)
Organ system
Organ system
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organ
Organ
Fig. 1.2b1
Cellular Level
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Cells are the basic unit of life
Organelles are tiny organs of the
cell
Molecules are clusters of atoms
Atoms are the basic units of matter
Atoms
Molecule
Organelle
Cell
Fig. 1.2a5
Fig. 1.2a4
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molecules
Molecule
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atoms
Atoms
Emergent Properties
 Emergent
properties result from the
arrangement and interaction of parts within
a system
 Emergent properties characterize
nonbiological entities as well

For example, a functioning bicycle emerges only
when all of the necessary parts connect in the
correct way
Systems in Biology
Biologists today combine reductionism with
systems biology, the exploration of a biological
system by analyzing the interactions among its
parts
 The systems approach poses questions such as
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How does a drug for blood pressure affect other
organs?
How does increasing CO2 alter the biosphere?
Structure and Function
At each level of the biological hierarchy we find
a correlation between structure and function
 Analyzing a biological structure can give clues
about what it does and how it works

2. Theme:
Life’s processes involve the expression of
Genetic Information
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Genes are made of DNA
Heredity depends on the copying of DNA
from one generation to the next
Genome: entire set of DNA instructions
within a cell
DNA Double Helix
3. Theme:
Life Requires the Transfer and Transformation
of Energy and Matter

Input of energy, mainly from the sun, and
transformation of energy from one form to
another make life possible
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Plants and other photosynthetic organisms convert the
energy of sunlight into the chemical energy of sugars
This chemical energy of these producers is then passed
to consumers that feed on the producers
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Energy flows through an ecosystem, generally
entering as light and exiting as heat
Chemical elements are recycled within an ecosystem
Energy flow
Chemicals
pass to
organisms
that eat plants.
Light
energy
Chemical
energy
Chemical
elements
Heat
Decomposers
return
chemicals
to soil.
4. Theme:
Organisms Interact with Other Organisms and
the Physical Environment
 Every
organism interacts with physical
factors in its environment
 Both organisms and their environments are
affected by the interactions between them

For example, a tree takes up water and minerals
from the soil and carbon dioxide from the air; the
tree releases oxygen to the air, and roots help
form soil
Interactions between organisms include those that
benefit both organisms and those in which both
organisms are harmed
 Interactions affect individual organisms and the way
that populations evolve over time

The Core Theme of Biology:
Evolution

Evolution makes sense of everything we know
about living organisms:
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Evolution explains patterns of unity and diversity in living
organisms
Similar traits among organisms are explained by
descent from common ancestors
Differences among organisms are explained by of
inheritable changes
Evolution
Classifying the Diversity of Life:
The Three Domains of Life
Humans group diverse items according to their
similarities and relationships to each other
 Studies of form and function has been used to
classify life-forms

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Recently, new methods of assessing species
relationships, especially comparisons of DNA
sequences, have led to a reevaluation of larger
groupings
Biologists categorize all living things
Into 3 groups called domains
The 3 Domains of Life

3 Biological Domains:
1. Bacteria (prokaryotic cells)
2. Archaea (prokaryotic cells)
3. Eukarya (eukaryotic cells)
A. Protista
B. Plantae
C. Fungi
D. Animalia
2 m
2 m
(b) Domain Archaea
(a) Domain Bacteria
(c) Domain Eukarya
Kingdom
Animalia
100 m
Kingdom
Plantae
Kingdom Fungi
Protists
Darwin’s
theory of
evolution
illustrates
how science
works
The Science of Biology
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Nearly 180 yrs ago, Charles Darwin set sail
on a journey on board the H.M.S. Beagle
His findings led directly to his development
of the Theory of Evolution
This theory has become the core of the
science of biology
Charles Darwin
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English Naturalist: 5 year voyage around coasts of South
America
Studied and made observations for over 30 years of various
plants and animals
Wrote “On the Origin of Species”
Living things have changed during the course of life on earth
His theory of natural selection did not challenge the existence
of a Divine Creator-He believed that this Creator did no
simply create things and then leave them forever unchanged.
Instead He expressed himself through the operation of
natural laws that produced change over time, thus evolution.
Charles Darwin published On the Origin of
Species by Means of Natural Selection in 1859
 Darwin
made two main points

1. Species showed evidence of “descent with
modification” from common ancestors

2. Natural selection is the mechanism behind
“descent with modification”
 Darwin’s
theory captured the duality of unity
and diversity
 Darwin
observed that
Individuals in a population vary in their traits, many of
which are heritable
 More offspring are produced than survive, and
competition is inevitable
 Species generally suit their environment
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 Darwin
determined:
Individuals that are best suited to their environment
are more likely to survive and reproduce
 Over time, more individuals in a population will have
the advantageous traits
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other words, the environment “selects” for
the propagation of beneficial traits
 Darwin called this process natural selection
 In
Darwin’s Evidence
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Drew ideas from Charles Lyell’s “Principles of Geologyspecies were becoming extinct while others were emerging
1.Observed fossils of extinct armadillos (Glyptodonts) that
were similar to armadillos still living in the area-Why would
similar living and fossil organisms be in the same area unless
the earlier form had given rise to the other?
In rock strata, progressive changes in characteristics can be
seen in fossils from earlier and earlier layers.
2. Geographical Distribution
a. Lands with similar climates (Australia, S. Africa,
California, and Chili), have unrelated plants and
animals indicating that diversity is not entirely
influenced by climate and environment.
b. The plants and animals of each continent are
distinctive.
3. Oceanic Islands
a. Endemic species show relatedness to one anotherThis suggests that they developed after their
mainland ancestors reached the islands. (Galapagos
tortoises)
b. Species on oceanic island show strong affinities to
those on the nearest mainland. (Galapagos finches)
One example: the Galapagos

On the Galapagos Islands, Darwin studied
many species of animals and plants that are
unique to the islands but similar to species
elsewhere.

He realized that individuals struggle to compete
in changing environmental conditions.
Galapagos tortoise are the largest
On Earth, different from other
Tortoises in body size and shape
Galapagos
finch
Is adapted
to feed
On cacti.
Galapagos marine iguanas
Eat algae from the ocean
Large claws help to cling
To slippery rocks
Natural Selection
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Natural selection is a
mechanism for change in
populations.
It occurs when organisms
with favorable variations
survive, reproduce, and
pass their variations to the
next generation.
As a result, each generation
consists largely of offspring
from parents with these
variations that aid survival.
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In nature, organisms
produce more offspring
than can survive
Darwin proposed this
idea of natural selection
to explain how species
change over time
Darwin explains natural selection

In any population,
individuals have
variations. Fishes,
for example, may
differ in color, size,
and speed.
Darwin explains natural selection

Individuals with certain
useful variations, such as
speed, survive in their
environment, passing those
variations to the next
generation.
Darwin explains natural selection

Over time, offspring with
certain variations make
up most of the population
and may look entirely
different from their
ancestors.
The Effects Of Natural Selection
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Natural selection can significantly alter the
genetic equilibrium of a population’s gene pool
over time
Significant changes in the gene pool
could lead to the evolution of a new
species over time
Speciation
•
The evolution of new
species, a process called
speciation occurs when
members of similar
populations no longer
interbreed to produce
fertile offspring within
their natural
environment.
Geographic Isolation

Geographic isolation
occurs whenever a
physical barrier
divides a population
Isolated habitat
fragments are similar to
islands in the way in
which the species living
there are effected.
https://www.youtube.com/watch?v=BE77igZczlI
GEOGRAPHIC ISOLATION
Artificial Selection
artificial selection is the process of intentional or unintentional
modification of a species through human actions which encourage
the breeding of certain traits over others
Darwin hypothesis that there was a force in nature that worked like
artificial selection
Adaptations for Evolution
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According to
Darwin’s theory,
adaptations in
species develop
over many
generations.
Evolution after Darwin: More
Evidence
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More extensive fossil record -support
Darwin’s theory of natural selection
Mechanism of heredity-Genetics accounts
in a neat and orderly way for the production
of new variations in organisms
Comparative Anatomy
Molecular evidence: -DNA evidence
Other Evidence
Anatomy
Homologous Structures: Similar
In arrangement, function or in both
Analogous Structures:
Similar body parts in
function w/ no evolutionary
origin
Vestigial Structure: A body structure in a
present day organism
That no longer serves its original purpose,
but was useful to
An ancestor
Human
Cat
Bat
Porpoise
Horse
Fossil Evidence
Fossils are important in Evolution
Because they provide a record
Of early life and history
Fossils – the clues to the past
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About 95 percent of
the species that have
existed are extinct—
they no longer live on
Earth
Among other
techniques, scientists
study fossils to learn
about ancient species.
Scientific Method
The experimental testing of a
hypothesis formulated after the
systematic, objective collection of
data
The Nature of Science
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Biology is FACINATING…AND
IMPORTANT
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Biologists are working on cures for disease such
as AIDS & cancer
Explains what our world is like
Solve environmental problems
Use and discover new technology
Scientific Method
Scientific Method

The methods of science are based on 2
principles:
1. Events in the natural world have natural
causes
Ex: ancient Greeks believed that lightning &
thunder occurred b/c a supernatural god Zeus
hurled thunderbolts from the heavens
Scientific Method
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2 principles
2. Uniformity: is the idea that the
fundamental laws of nature operate the
same way at all places and at all times
Ex: scientists assume that the law of gravity works
the same way on Mars as it does on Earth.
How Science Is Done
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1. Observation or Ask a Question
2. Do background research
3. Hypothesis
4. Controlled Experiment (test hypothesis)
5. Collect & Analyze Data
6. Draw a Conclusion
7. Develop Theory
Hypotheses are accepted or rejected based on
experimental results.
Biologist reason in 2 ways:
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1. Deductive Reason
2. Inductive Reason
Deductive Reasoning
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Applies general principles to predict
specific results.
Logic flows from general to specific
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The hypothesis is then tested experimentally
Inductive Reasoning:
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Draws conclusions through the logical process
Applies specific principles to predict general results.
Generalizations are drawn from a large number of
observations
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Example: Cats have fur, dogs have fur, and every mammal you
observe has fur, then you may infer that all mammals have hair.
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Example: “all organisms are made of cells” was based on two
centuries of microscopic observations
Establishing Controls (variables)
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Independent Variable: the manipulated
variable (changing)
Dependent Variable: responding variable,
it is affected by the independent variable
(happens because of something)
If a scientist conducts an experiment to test the theory that a
vitamin could extend a person’s life-expectancy, then:
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The independent variable is the amount of
vitamin that is given to the subjects within
the experiment. This is controlled by the
experimenting scientist.
The dependent variable, or the variable
being affected by the independent variable,
is life span.
In Other Words…..
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The dependent variable is usually the result
of the experiment, the thing you measure.
The independent variable is what causes
the results.
Using Conclusions
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A hypothesis is most useful when it makes
predictions, because predictions provide a way to
test the validity of the hypothesis
If experimental results are inconsistent with the
predictions then the hypothesis must be rejected.
If experimental results are consistent with the
predictions then the hypothesis must be accepted.
Mythbusters…
https://www.youtube.com/watch?v=iHu6LV
g-0Hs
Waterslide wipeout
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Observation
Question
Hypothesis
Hypothesis
Hypothesis
Hypothesis
Hypothesis
Potential
hypotheses
1
2
3
4
5
Fig. 1.4
Experiment
Hypothesis 2
Hypothesis 3
Hypothesis 5
Remaining
possible
hypotheses
Reject
hypotheses
1 and 4
Experiment
Hypothesis 5
Reject
hypotheses
2 and 3
Last remaining
possible hypothesis
Predictions
Experiment 1
Experiment 2 Experiment 3
Predictions
confirmed
Experiment 4
Basic vs Applied Research
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Basic research expands the boundaries of
what we know and is usually performed at
Universities
Applied research is conducted by scientists
in industry. Example food additives, new
drugs, testing environmental quality