Chapter 1iris.nyit.edu/~jlee26/pics/rptse/Eng RPTSE Bio Ch. 01.pdf · Chapter 1 Introduction: Biology Today RPTSE BIO Fall 2015 Jong B. Lee, PhD, All rights reserved. ... 4 RPTSE

RPTSE Biology – Fall 2015, Dr. Jong B. Lee 1

© Jong B. Lee, Ph.D.

Chapter 1

Introduction: Biology Today

RPTSE BIO Fall 2015 Jong B. Lee, PhD, All rights reserved.

Living in a Golden Age of Biology

• We are living in a golden age of biology

• Biology provides exciting breakthroughs

changing our culture.

– Molecular biology is solving crimes

and revealing ancestries.

– Ecology helps us address

environmental issues.

– Neuroscience and evolutionary

biology are reshaping psychology

and sociology.


• Biology is the scientific study of life: It’s a subject of

enormous scope that gets bigger every year.

The Scope of Life

• What is life?

: The phenomenon of life seems to defy a simple, one-

sentence definition.

Order, Regulation, Growth & Development, Energy

utilization, Response to the environment, Reproduction

The properties of Life


f Reproduction

g Evolutiona Order b Regulation

c Growth and development d Energy utilization

The properties of Lifee Response to the environment



Figure 1.2.1

Life at Its Many Levels

• Biologists explore life at

levels ranging from the

biosphere to the

molecules

• At each new level, novel

properties emerge,

properties that were not

part of the components of

the proceeding level.

“ The whole is greater

than the sum of its parts”

Ex) Life emerges at the

level of cellRPTSE BIO Fall 2015 Jong B. Lee, PhD, All rights reserved.

• Population (개체군 ): Groups of interacting individuals of

one species (ex: A herd of zebras)

The next: Organisms organ systems organs

tissues cells molecules atoms

• The biosphere (생물권) is enriched by a great variety of

ecosystems.

All the environments on Earth that support life

• An ecosystem (생태계): consists of all organisms in a

particular area, as well as the nonliving, physical

components of the environment that affect the organisms

• Community (군집): All the organisms in a particular area


• Each organism interacts continuously with its

environment, which includes other organisms as well

as nonliving factors.

Ecosystems (생태계)

– Both organisms and environment are affected by the

interactions

– Ecology is the branch of biology that investigates

these relationships between organisms and their

environment


The dynamics of Ecosystem

The dynamics of any

ecosystem depend on

two processes

– Cycling of

nutrients

(recycle)

– Flow of energy

(one way)

Figure 1.3

Chemicalenergy (food)



The cell is the lowest level of structure that can perform

all activities required for life

Cells and Their DNA

– All organisms are composed of cells

(unicellular and multicellular)

– Cells: basis for all reproduction, growth, and repair


• We can distinguish two major types of cells

– Prokaryotes (원핵생물): bacteria

– Eukaryotes (진핵생물): bacteria 이외의모든생물

보통식물, 동물들


Prokaryotic cell

Nucleoid

region

Organelles

Nucleus

Co

lori

zed

TE

M

(bacterium)

•

Simpler structure•

•

•

Smaller

DNA concentrated innucleoid region, whichis not enclosed bymembrane

Lacks most organelles

•

Eukaryotic cell

Larger

More complexstructure

Nucleus enclosedby membrane

Contains many

•

•

•

•

types of organelles


• The prokaryotic cell is

simple and contains no

organelles

• The eukaryotic cell is more

complex and contains

organelles

• The nucleus is the largest organelle in most eukaryotic

cells

• Eukaryotic cells is subdivided by internal membranes into

organelles.



– Genes are the units of

inheritance that transmit

information from parents to

offspring

• The language of DNA contains

just four letters: A, G, C, TFigure 1.5

• Though very different in structural

complexity, prokaryotic and eukaryotic cells

have much in common at the molecular level

• All cells use DNA as the chemical material of

genes


Genetic engineering and biotechnology have allowed us to

manipulate the DNA and genes of organisms

human insulin hormone production in bacteria

It is only possible because biological information is

written in the universal chemical language of DNA

How is bacteria able to produce human insulin?


Human genome의 sequence 해독 완성: 2001

– The entire “book” of genetic instructions of an

organism : “Genome”

– Human: 3.2 x 109 base pairs

– The genome sequences of other species

(E. coli, fruit fly, mouse) are completed

– Genomics (유전체학) – a branch of biology that studies

whole genomes


Diversity is the hallmark (상징) of life

Life in Its Diverse Forms

– The diversity of known life includes 1.8 million

species ( insects : more than 1 million)

– Estimates of the total diversity range from 10 million

to over 200 million species



Grouping Species

• Biodiversity can be

both beautiful and

overwhelming

• Taxonomy is the

branch of biology

that names and

classifies species

Figure 1.7


DO

MA

IN

BA

CT

ER

IA

DO

MA

IN

AR

CH

AE

A

DO

MA

IN E

UK

AR

YA

Kingdom Plantae

Kingdom Fungi

Kingdom Animalia

Protists (multiple kingdoms)

TE

MC

olo

rized

TE

M

LM

The Three Domains of Life

The kingdoms of life can now

be assigned to three even

higher levels of classification

called domains.

(Bacteria, Archaea, Eukarya)


Bacteria and Archaea are both prokaryotic domains

Figure 1.8.2


DOMAIN EUKARYA

Kingdom Plantae 식물계 Kingdom Fungi 곰팡이계

Kingdom Animalia 동물계 Protists 원생생물계 multiple kingdoms

: Generally single celled

LM

Eukarya includes at least four kingdoms



• These three multicellular kingdoms (식물, 동물, 곰팡이) are

distinguished by how they obtain food.

– Plants produce their own sugars and other foods by

photosynthesis.

– Fungi are mostly decomposers, digesting dead

organisms.

– Animals obtain food by eating and digesting other

organisms.

• Those eukaryotes that do not fit into the other three

kingdoms are referred the as the protists: generally

singled cells (amoebas..) and multicellular seaweeds


Underlying the diversity of life is a striking unity, especially

at the lower levels of structure

What can account for this combination of unit and diversity?

“Evolution”

Unity (통일성 ) in the Diversity of Life

Ex: The universal genetic language of DNA


The history of

life is a saga

(무용담) of a

restless Earth

billions of years

old

EVOLUTION: BIOLOGY’S UNIFYING THEME

: Fossils

document this

history


Ancestral

bear

Common ancestor of

polar bear and brown bear

Giant panda

Spectacled bear

Sloth bear

Sun bear

American black bear

Asiatic black bear

Polar bear

Brown bear

30 25 20 15 10 5

Millions of years ago

• All of life

is connected

• Each species is one twig of a branching tree of life

extending back in time (화석기록과유전적정보를근거로)



The evolutionary

view of life came into

focus in 1859 when

Charles Darwin

published The Origin

of Species

The Darwinian View of Life


Darwin’s book developed two main points

1) Contemporary species arose from a succession of

ancestors

◦ Darwin called this evolutionary history of species

“descent with modification”

(변형되어혈통잇기 곧진화를일컬음)

2) Natural selection (자연선택; 진화의작동원리)

Darwin proposed a mechanism for descent with

modification, he called this process natural selection.


Natural Selection

• Darwin was particularly struck by the

diversity of animals on the Galapagos

Islands.

• He thought of adaptation to the environment and the

origin of new species as closely related processes

– If some geographic barrier (an ocean separating

islands) isolated two populations of a single species,

the populations could diverge more and more in

appearance as each adapted to local environmental

conditions. Over many generations, the two

populations could become dissimilar enough to be

designated separate species


• Darwin synthesized the concept of natural selection

from two observations that by themselves were

neither profound nor original

• Others had the pieces of the puzzle, but Darwin

could see how they fit together.

Darwin’s Inescapable Conclusion

• Observation 1: Overproduction and competition

• Observation 2: Individual variation

(Individuals in a population of any species vary in

many heritable traits)



• Conclusion:

“ Unequal reproductive success”

– It is this unequal reproductive success that Darwin

called natural selection

– The product of natural selection is adaptation, the

accumulation of favorable variations in a population

over time


Natural selection is the

mechanism of evolution

Avoiding predation is

the key in this case.

Population with varied inherited traits of beetles

Elimination of individuals with certain traits

Reproduction of survivors

Increasing frequency of traits that enhance survival and reproductive success

1

2

3

4


Observing Artificial Selection

Artificial selection is the selective breeding of

domesticated plants and animal by humans (humans were

substituting for the environment in screening heritable trait)


b Domesticated dogs descended from wolves

Domesticated dogs Gray wolves



The Process of Science

• The word science is derived from a Latin verb

meaning “to know.”

• Science is a way of knowing.

• Science developed from people’s curiosity about

themselves and the world around them.

• This basic human drive to understand is manifest in two

main scientific approaches: discovery science and

hypothesis-driven science


1. Discovery Science

• Verifiable observations and measurements are the data

of discovery science.

– In biology, discovery science enables us to describe

life at its many levels.

Ex) Darwin’s careful description of the diverse plants

and animals, The sequencing of the human genomes,


• Discovery science can

lead to important

conclusions based on

a type of logic called

inductive reasoning.

: An inductive conclusion is

a generalization that

summarizes many

concurrent observations.

(specific general)


Observation:

My flashlightdoesn’t work.

Question:What’s wrong

with myflashlight?

Prediction:If I replace thebatteries, theflashlight will

work.

Experiment:I replace the

batteries withnew ones.

Experimentsupports

hypothesis;

make additionalpredictions

and test them.

Experiment does

not supporthypothesis; revise

hypothesis orpose new one.

Revise

Hypothesis:The flashlight’s

batteries

are dead.

2. Hypothesis-Driven Science

• The observations of discovery science stimulate us to

ask questions and seek explanations As a formal process

of inquiry , the scientific method consists of series of steps.



• In the process of science, the deduction usually

takes the form of predictions about experimental

results.

• Then the hypothesis is tested by performing an

experiment to see whether results are as predicted.

• A hypothesis is a tentative answer to some question.

: It is an explanation on trial.


The Process of Science: Is Trans Fat Bad for You?

• One way to better understand how the process of science

can be applied to real-world problems is to examine

a case study, an in-depth examination

of an actual investigation.

© 2010 Pearson Education, Inc.

• Dietary fat comes in different forms.

: Trans fat is a non-natural form produced through

manufacturing processes.


• A hypothesis-driven study published in 2004

– Started with the observation that human body fat

retains traces of consumed dietary fat.

– Asked the question: Would the adipose tissue of

heart attack patients be different from a similar

group of healthy patients?

– Formed the hypothesis that healthy patients’ body

fat would contain less trans fat that the body fat in

heart attack victims.

• The researchers set up an experiment to determine the

amounts of fat in the adipose tissue of 79 patients who

had a heart attack.RPTSE BIO Fall 2015 Jong B. Lee, PhD, All rights reserved.

• The results showed significantly higher levels of trans

fat in the bodies of the heart attack patients.

• They compared these patients

to the data for 167 patients

who had not had a heart

attack.

• This is an example of a

controlled experiment, in

which the control and

experimental groups differ

only in one variable—the

occurrence of a heart attack.



The Culture of Science

• Scientists build on what has been learned from earlier

research: They pay close attention to contemporary

scientists working on the same problem.

• Cooperation and competition characterize the scientific

culture: Scientists check the conclusions of others by

attempting to repeat experiments.


Science, Technology, and Society

• Science and technology are interdependent.- New technologies advance science.

- Scientific discoveries lead to new technologies.

ex) the discovery of the structure of DNA about 50

years ago led to a variety of DNA technologies.

• Technology has improved our standard of living in

many ways, but it is a double-edged sword.

- Technology that keeps people healthier has enabled

the human population to double to nearly 7 billion in

just the past 40 years.

- The environmental consequences of this population

growth may be devastating.


There are many examples of natural selection in action

Evolution connection: Evolution in our Everyday Lives

– Antibiotics have saved millions of human lives, but

there’s a dark side: It has driven the evolution of

antibiotic-resistant populations of bacteria.

– The development of antibiotic-resistant bacteria is

one (예: 결핵균)

Figure 1.16


• It is important to note that adaptation of antibiotic-

resistant bacteria does not mean that the drugs created

the favorable characteristics.

• Instead, the environment screened the heritable

variations that existed among individuals of a population

and favored the ones best suited to present conditions.



• Darwin’s publication of The Origin of Species

fueled an explosion in biological research

– Evolution is one of biology’s best demonstrated,

most comprehensive, and longest lasting theories

– Dobzansky (1973)

“ Nothing in biology makes sense except in light of

evolution”

Evolution is the unifying theme of biology

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Chapter 1iris.nyit.edu/~jlee26/pics/rptse/Eng RPTSE Bio Ch. 01.pdf · Chapter 1 Introduction: Biology Today RPTSE BIO Fall 2015 Jong B. Lee, PhD, All rights reserved. ... 4 RPTSE