Upload
jordan-junot
View
27
Download
2
Tags:
Embed Size (px)
DESCRIPTION
Chapter 1 Slides
Citation preview
BSC 108
1
CHAPTER 1CHAPTER 1
Introduction: Biology Today
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Lectures by Chris C. Romero
PowerPoint® Lectures forEssential Biology, Third Edition
– Neil Campbell, Jane Reece, and Eric SimonEssential Biology with Physiology, Second Edition
– Neil Campbell, Jane Reece, and Eric Simon
• We are living in a golden age of biology.
– Modern biology is as important as it is inspiring with
Biology and Society
Figure 1.1
inspiring, with exciting breakthroughs changing our very culture.
BSC 108
2
• Biology is the scientific study of life.
The Scope of Life
– Life is structured on a size scale ranging from the molecular to the global.
– Biology’s scope stretches across the enormous diversity of life on Earth.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
y
• The phenomenon we call life defies a simple, one-sentence d fi i i
The Unity of Life
Figure 1.2
definition.
• Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.
Life at Its Many Levels
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Figure 1.3
BSC 108
3
Ecosystems
• Each organism interacts continuously with its environment.
– Both organism and environment are affected by the interactions.
• The dynamics of any ecosystem depend on two
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
The dynamics of any ecosystem depend on two processes:
– Cycling of nutrients
– Flow of energy
Figure 1.4
Cells and Their DNA
• The cell is the lowest level of structure that can perform all activities required for life.
– All organisms are composed of cells.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
• We can distinguish two major types of cells:
– Prokaryotic
– Eukaryotic
BSC 108
4
• The prokaryotic cell is simple, small, and contains no organelles.
• The eukaryotic cell is larger and more complex and contains organelles.
– The nucleus is the largest organelle in most
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
The nucleus is the largest organelle in most eukaryotic cells.
Figure 1.5
• All cells use DNA as the chemical material of genes.
– Genes are the units of inheritance that transmit information from parents to offspring
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
offspring.
• The language of DNA contains just four letters:
– A, G, C, T
Figure 1.6
BSC 108
5
• Genetic engineering and biotechnology have allowed us to manipulate the DNA and genes of organisms.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Figure 1.7
Life in Its Diverse Forms
• Diversity is the hallmark of life.
– The diversity of known life includes 1.8 million species.
– Estimates of the total diversity range from 10 million to over 200 million species.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
p
– Biodiversity can be both beautiful and overwhelming.
Grouping Species: The Basic Concept
• Taxonomy is the branch of biology that names and classifies species.
– It formalizes the hierarchical ordering of organisms.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Figure 1.8
BSC 108
6
The Three Domains of Life
• The three domains of life are:
– Bacteria
– Archaea
– Eukarya
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
• Bacteria and Archaea are both prokaryotic domains.
Figure 1.9.1
• Eukarya includes at least four kingdoms:
– Plantae
– Fungi
– Animalia
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
– Protista
Figure 1.9.2
BSC 108
7
Unity in the Diversity of Life
• Underlying the diversity of life is a striking unity, especially at the lower levels of structure.
– Example: the universal genetic language of DNA
• Biological evolution accounts for this combination of unity and diversity
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
of unity and diversity.
Evolution: Biology’s Unifying Theme
• The history of life is a saga of a restless Earth billions of years old.
– Fossils document this history.
• Life evolves.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Figure 1.10
– Each species is one twig of a branching tree of life extending back in time.
Figure 1.11
BSC 108
8
The Darwinian View of Life
• The evolutionary view of life came into focus in 1859 when Charles Darwin published The Origin of Species.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Figure 1.12
• Darwin’s book developed two main points:
– Descent with modification
– Natural selection
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Natural Selection
• Darwin was struck by the diversity of animals on the Galápagos Islands.
• He thought of adaptation to the environment and the origin of new species as closely related processes.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
– As populations separated by a geographic barrier adapted to local environments, they became separate species.
• Fourteen species of Galápagos finches have beak shapes adapted to suit their environments.
BSC 108
9
Figure 1.13
Darwin’s Inescapable Conclusion
• Darwin synthesized the theory of natural selection from two observations that were neither profound nor original.
– Others had the pieces of the puzzle, but Darwin could see how they fit together.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
• Fact 1: Overproduction and competition
• Fact 2: Individual variation
• The inescapable conclusion: Unequal reproductive success
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
– It is this unequal reproductive success that Darwin called natural selection.
– The product of natural selection is adaptation.
• Natural selection is the mechanism of evolution.
BSC 108
10
Figure 1.14
Observing Artificial Selection
• Artificial selection is the selective breeding of domesticated plants and animals by humans.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Figure 1.15
Observing Natural Selection
• There are many examples of natural selection in action.
– The development of antibiotic-resistant bacteria is one.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Figure 1.16
BSC 108
11
• Darwin’s publication of The Origin of Speciesfueled an explosion in biological research.
– Evolution is one of biology’s best demonstrated, most comprehensive, and longest lasting theories.
– Evolution is the unifying theme of biology.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
y g gy
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.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Discovery Science
• Science seeks natural causes for natural phenomena.
– This limits the scope of science to the study of structures and processes that we can observe and measure.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
• Verifiable observations and measurements are the data of discovery science.
– In biology, discovery science enables us to describe life at its many levels.
BSC 108
12
Figure 1.17
• 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.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Hypothesis-Driven Science
• As a formal process of inquiry, the scientific method consists of a series of steps.
– The key element of the scientific method is hypothesis-driven science.
• A hypothesis is a tentative answer to some
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
A hypothesis is a tentative answer to some question.
– It is an explanation on trial.
BSC 108
13
Figure 1.18
• Once a hypothesis is formed, an investigation can use deductive logic to test the hypothesis.
– In deduction, the reasoning flows from the general to the specific.
• In the process of science, the deduction usually
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
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.
Figure 1.19
BSC 108
14
The Process of Science: Can Colors Protect a Snake?
• One way to learn more about how hypothesis-based science works is to examine a case study, an in-depth examination of an actual investigation.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Figure 1.20
• Biologists developed a hypothesis regarding mimicry in snakes.
– They tested the hypothesis by making artificial snakes and observing how often they were attacked by predators.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
BSC 108
15
Figure 1.21
• This is an example of a controlled experiment.
– Such an experiment is designed to compare an experimental group with a control group.
– Ideally, a control group and an experimental group differ in only one variable.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
y
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.
• Both cooperation and competition characterize the
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
Both cooperation and competition characterize the scientific culture.
– Scientists check the conclusions of others by attempting to repeat experiments.
BSC 108
16
Science, Technology, and Society
• Science and technology are interdependent.
– New technologies advance science.
– Scientific discoveries lead to new technologies.
– For example, the discovery of the structure of DNA 50 l d i f DNA
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
DNA 50 years ago led to a variety of DNA technologies.
Figure 1.23
Evolution Connection: Theories in Science
• What is a scientific theory, and how is it different from a hypothesis?
– A theory is much broader in scope than a hypothesis.
– Theories only become widely accepted in science
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings
y y pif they are supported by an accumulation of extensive and varied evidence.