General Biology I For M117 and D76 Students

陳 正 繹

Dept. of Biology & Anatomy

National Defense Medical Cente

Text Book

USA Edition : Traditional Global Edition

Lecture Presentations by Nicole Tunbridge and

Kathleen Fitzpatrick

Chapter 1

Evolution, the

Themes of

Biology, and

Scientific Inquiry

© 2017 Pearson Education, Inc.

Lecture Presentations by Nicole Tunbridge and

Kathleen Fitzpatrick

Chapter 1

Biology and Its

Themes

© 2018 Pearson Education Ltd.

1.0 Inquiring About Life

• An “organisms” adaptations to its environment are the result of evolution

– For example, the color of the beach mouse has come to be well matched, or adapted, to its local background

What can this beach mouse teach us about biology?

An inland mouse of the species

Peromyscus polionotus

•Evolution 演化is the process of change that has transformed life on Earth

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• Evolution 演化is the process of change that has transformed life on Earth

• Biology 生物學is the scientific study of life • Biologists生物學家ask questions such as:

1. How a single cell develops into an organism. 2. How the human mind works. 3. How living things interact in communities

Life defines a simple, one-sentence definition

“Life is recognized by what living things do”

Order 秩序 Evolutionary adaptation 演化的適應 Response to the environment 對環境的反應 Regulation 調節 Energy processing 能量的形成 Growth and development 生長與發育 Reproduction 生殖

Some properties of life

Key Concepts

1.1 The Study of Life Reveals Unifying Themes

1.2 The Core Theme: Evolution accounts for the unity and diversity of life

1.3 In studying nature, scientists make observations and form and test hypotheses

1.4 Science benefits from a cooperative approach and diverse viewpoints

1.1 The Study of Life Reveals Unifying Themes.

• Biology is a subject of enormous scope

• There are five unifying themes

– Organization

– Information

– Energy and matter

– Interactions

– Evolution

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Life can be studied at different levels from molecules to the entire living planet. This enormous range can be divided into different levels of biological

organization

A. Theme: New properties emerge at successive level of the biological organization

Exploring level of biological organization:

Biosphere 生物圈 Ecosystems 生態系 Communities 群落 Populations 族群 Organisms 生物體 Organs 器官 Tissue 組織 Cell 細胞 Organelle 胞器 Molecular 分子 Atom 原子

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1. Emergent properties a. Emergent properties新穎特質 result from the arrangement and

interaction of parts within a system b. Emergent properties characterize non-biological entities as well

Ex., a functioning bicycle emerges only when all of the necessary parts connect in the correct way

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c. Reductionism 化約主義,簡化論is the reduction of complex systems to simpler components that are more manageable to study Ex. studying the molecular structure of DNA helps us to understand the chemical basis of inheritance

d. To explore emergent properties, biologists complement reductionism with systems biology, analysis of the interactions among the parts of a biological system .

2. Structure and Function

• At each level of the biological hierarchy 階層we find a correlation between structure and function

Hummingbirds

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3. The Cell: An Organism’s Basic Units of Structure and Function

a. The cell is the lowest level of organization that can perform all activities required for life

b. All cells are enclosed by a membrane, use DNA as their genetic information

c. A eukaryotic cell真核細胞 has membrane-enclosed organelles膜性胞器, the largest of which is usually the nucleus

d. By comparison, a prokaryotic cell原核細胞 is simpler and usually smaller, and does not contain a nucleus or other membrane-enclosed organelles.

Contrasting eukaryotic and prokaryotic cells in size

and complexity

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B. Theme: Life’s Processes Involve the Expression and Transmission of Genetic Information

Within cells, structures called chromosomes染色體contain genetic material in the form of DNA (deoxyribonucleic acid)

A lung cell from a newt divides into two smaller cells that grow and divide again

Inherited DNA directs development of an organism

1. DNA, the Genetic Material a. Each chromosome has one long DNA molecule with hundreds or

thousands of genes b. Genes encode information for building the molecules synthesized

within the cell

c. Genes are the units of inheritance d. DNA controls the development and

maintenance of organisms

21 DNA: The genetic material

e. Each DNA molecule is made up of two long chains arranged in a double helix

f. Each link of a chain is one of four kinds of chemical building blocks called nucleotides核苷酸.

Figure 1.8

Lens

cell

(a) Lens cells are

tightly packed

with transparent

proteins called

crystallin.

(b) How do lens cells make crystallin proteins?

Crystallin gene

DNA

mRNA

Chain of amino

acids

Protein

Crystallin protein

TRANSCRIPTION

TRANSLATION

A C C A A A C C G A G T

T G G T T T G G C T C A

U G G U U U G G C U C A

PROTEIN FOLDING

g. Genes control protein production indirectly

h. DNA is transcribed into RNA then translated into a protein.

i. Gene expression is the process of converting information from gene to

cellular product

Gene expression: The transfer of information from a gene results in a functional protein

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e. The genomics approach depends on:

i.“High-throughput” technology高通量科技, which yields enormous amounts of data.

ii. Bioinformatics, 生物資訊 which is the use of computational tools to process a large volume of data.

iii. Interdisciplinary research teams跨學科的研究團隊

2. Genomics: Large-Scale Analysis of DNA Sequences.

Biology as an information science

a. An organism’s genome 基因體is its entire set of genetic instructions. b. The human genome and those of many other organisms have been

sequenced using DNA-sequencing machines. c. Genomics基因體學is the study of sets of genes within and between species d. Proteomics 蛋白質體學is the study of sets of proteins and their properties .

Entile sets of proteins encoded by the genome (known as proteomes)

C. Theme: Life Requires the Transfer and Transformation of Energy and Matter

• The input of energy from the sun and the transformation of energy from one form to another make life possible

• The chemical energy generated by plants and other photosynthetic organisms (producers生產者) is passed along to consumers消費者

• Consumers are organisms that feed on other organisms or their remains

• When organisms use energy to perform work, some energy is lost to the surroundings as heat

• As a result, energy flows能量流動 through an ecosystem, usually entering as light and exiting as heat

Energy flow and chemical cycling

D. Theme: From Molecules生態系to Ecosystems, Interactions Are Important in Biological Systems

• Interactions between the components of the system ensure smooth integration of all the parts. This holds true equally well for components of an ecosystem and the molecules in a cell

1. Molecules: Interactions With in Organisms

Interactions between components—organs, tissues, cells, and molecules—that make up living organisms are crucial to their smooth operation

Cells are able to coordinate various chemical pathways through a mechanism called feedback迴饋

Feedback mechanisms allow biological processes to self-regulate a. Negative feedback負向迴饋The most common form of

regulation in living organisms, in which the response reduces the initial stimulus, the process that creates it slows and less of the product is produced

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b. Positive feedback 正向迴饋:means that as more of a product accumulates, the process that creates it speeds up and more of the product is produced

Ex. Clotting of blood

2. Ecosystems: An Organism’s Interactions with Other Organisms and

the Physical Environment • At the ecosystem level, each organism interacts continuously with other

organisms, These interactions may be beneficial or harmful to one or both of the organisms

• Organisms also interact continuously with the physical factors in their environment, and the environment is affected by the organisms living there

Humans interact with our environment, sometimes with dire consequences

Over the past 150 years, humans have greatly increased the burning of fossil fuels and the release of carbon dioxide (CO2) into the atmosphere

The resulting global warming is just one aspect of climate change Wind and precipitation patterns are also shifting Extreme weather events such as storms and droughts are occurring more often As habitats deteriorate, plant

and animal species shift their ranges to more suitable locations

Populations of many species are shrinking in size or even disappearing

Threatened by global warming

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1.2: The core theme: Evolution accounts for the unity and diversity of life

• Evolution is the one idea that makes logical sense of everything we know about living organisms

• The scientific explanation for both the unity一致性and diversity多樣性of organisms is evolution, the concept that living organisms are modified descendants of common ancestors

• An abundance of evidence supports the occurrence of evolution.

“Nothing in biology makes sense except in the light of evolution”—Theodosius Dobzhansky (Neo-Darwinism新達爾文主義)

1. The Three Domains of Life a. Organisms are divided into three domains, named Bacteria細菌域, Archaea古細菌域, and Eukarya真核生物域

b. Domain Bacteriaand domain Archaeacomprise the prokaryotes (Kingdom Monera原核生物界)

c. Domain Eukarya includes all eukaryotic organisms The domain Eukarya includes three multicellular kingdoms: i. Plantae植物界, which produce their own food by

photosynthesis ii. Fungi真菌界, which absorb nutrients iii. Animalia動物界which ingest their food

d. Other eukaryotic organisms were formerly grouped into a called Protists kingdom原生生物界, though the recent trend has been to split the protists into several kingdoms

The three domains of life

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2. Unity一致性in the diversity of life An universal genetic code Similarities of cell structure

An example of unity underlying the diversity of life; the architecture of cilia(纖毛) in eukaryotes

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The history of life as documented by fossils and other evidence is the saga of a changing Earth, billions of years old

Digging the past

B. Charles Darwin and the theory of natural selection

1.Charles Darwin published “On the Origin of Species by Means of Natural Selection” in 1859

Darwin made two main points: • Species showed evidence of

“descent with modification”修飾的後裔from common ancestors 共通祖先

• Natural selection天擇 is the mechanism behind “descent with modification”

Charles Darwin as a young man

2. Darwin’s theory explained the duality of unity一致性and

diversity多樣性

Unity and diversity among the birds

Darwin observed that: •Individuals in a population have traits性狀 that vary •Many of these traits are heritable (passed from parents to offspring) •More offspring 子代are produced than survive •Competition is inevitable, species generally suit their environment

Darwin inferred that: • 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 • Evolution occurs as the unequal reproductive success of

individuals • In other words, the environment “selects” for the propagation of

beneficial traits. Darwin called this process natural selection天擇

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Natural selection

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Natural Selection Evolutionary adaptation Evolutionary adaptation

• Natural selection results in the adaptation of organisms to their environment. Ex. Bat wings are an example of adaptation, Form fits function 型式適合功能

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2.Fossils 化石provide additional evidence of anatomical unity from descent with

modification. 3.Darwin proposed that

natural selection could cause an ancestral species to give rise to two or more descendent species

4. Ex. the finch鶯 species of the Galápagos Islands are descended from a common ancestor

5. Evolutionary relationships are often illustrated with tree-like diagrams that show ancestors and their descendents

C. The tree of life 1.“Unity in diversity” arises from “descent with modification”.

Descent with modification: adaptive radiation 適應輻射

of finches 雀,鶯on the Galápagos Islands 加拉巴哥群島

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•The word Science is derived from Latin and means “to know” •Inquiry探究,探索is the search for information and explanation •The scientific process includes making observations, forming logical hypotheses, and testing them.

A. Exploration and observations

1.3: In studying nature, scientists make observations and

then form and test hypotheses

Jane Goodall collecting qualitative data on chimpanzee behavior

• Biologists describe natural structures and processes This approach is based on observation and the analysis of data數據.

• Recorded observations are called data

• Qualitative data: often take the form of recorded descriptions

• Quantitative data are generally expressed as numerical measurement, organized into tables and graphs

•Inductive reasoning歸納理由draws conclusions through the logical process of induction

•Repeating specific observations can lead to important generalizations Ex., “the sun always rises in the east” or “all organisms are made of cells”

B. Forming and Testing Hypotheses •In science a hypothesis假說an explanation, based on observations and assumptions, that leads to a testable prediction. It is usually a rational accounting for a set of observations觀察. It leads to predictions 預測that can be tested by making additional observations or by performing experiments

EX.:

i. Observation: Your desk lamp doesn’t work

ii. Question: Why doesn’t your desk lamp work?

iii. Hypothesis 1: The bulb is not screwed in properly

iv. Hypothesis 2: The bulb is burnt out v. Both these hypotheses are testable

A simplified view of the scientific process

1. Deductive Reasoning • Deductive reasoning推演uses general premises to make

specific predictions • Initial observations may give rise to multiple hypotheses • We can never prove that a hypothesis is true, but testing it

in many ways with different sorts of data can increase our confidence in it tremendously

2. Questions That Can and Cannot Be Addressed by Science • A hypothesis must be testable

EX.: a hypothesis that ghosts fooled with the flashlight cannot be tested

• Supernatural and religious explanations are outside the bounds of science

C. The Flexibility of the Scientific Process • The scientific method is an idealized process of inquiry • However, very few scientific inquiries adhere rigidly to this approach. • Backtracking回溯and “rethinking” may be necessary part way through

the process

The process of Science : A more realistic model

http://undsci.berkeley.edu/

http://undsci.berkeley.edu/article/howscienceworks_01

D. A Case Study in Scientific Inquiry: Investigating Coat Coloration in Mouse Populations • Color patterns of animals vary widely in nature, sometimes even between

members of the same species • Two populations of mice belonging to the same species (Peromyscus

polionotus) but with different color patterns are found in different environments

• The beach mouse lives on white sand dunes with sparse vegetation; the inland mouse lives on darker soil

Different coloration in beach and inland populations of Peromyscus polionotus

• The two types of mice match the coloration of their habitats, natural predators掠食者of these mice are all visual hunters

• Francis Bertody Sumner hypothesized that the color patterns had evolved as adaptations to protect the mice from predators

• 2010 Hopi Hoekstra and a group of students tested this hypothesis • The researchers predicted that mice that did not match their habitat would be preyed

on more heavily than mice that did match the surroundings • They built models of mice, painted them to match one of the surroundings, and placed

equal numbers of each type of model in each habitat • They then recorded signs of predation

Inquiry Dose camouflage affect predation on two population of mice?

E. Experimental Variables and Controls • In a controlled experiment, an experimental group實驗組

(the non-camouflaged mice in this case) is compared with a control group對照組(the camouflaged 偽裝mice)

• Experimental variables變數are features or quantities that vary in an experiment

• The independent variable自變數is the one that is manipulated by the researchers, while the dependent variable應變數is the one predicted to be affected in response

F. Theories in Science • In the context of science, a theory理論，原理，學說is

broader in scope than a hypothesis, general, and can lead to new testable hypotheses and supported by a large body of evidence in comparison to a hypothesis

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1.4: Science benefits from a cooperative approach and diverse viewpoints

Most scientists work in teams, which often include graduate and undergraduate students

Good communication is important in order to share results through seminars專題討論, publications出版物, and websites網路

Science as social process

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A.Building on the work of others Scientists check each others’ claims by performing similar experiments If experimental results are not repeatable, the original claim will have to

be revised It is not unusual for different scientists to work on the same research

question Scientists cooperate by sharing data about model organisms模式生物

(e.g., the fruit fly Drosophila melanogaster)

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B. Science, technology, and society The goal of science is to understand natural phenomena ;the goal of

technology is to apply scientific knowledge for some specific purpose Biology is marked by “discoveries”發現while technology is marked by

“inventions”發明 The combination of science and technology has dramatic effects on society Ethical issues倫理的爭議can arise from new technology, but have as much to

do with politics, economics, and cultural values as with science and technology

DNA technology and crime scene investigation

C. The Value of Diverse Viewpoints in Science

• Many important inventions have occurred where different

cultures and ideas mix

• Ex., the printing press 印刷術relied on innovations from China

(paper and ink) and Europe (mass production in mills)

• Science benefits from diverse views from different racial and

ethnic groups, and from both women and men

The End